Global Environmental Change [1 ed.] 9789400757837, 9789400757844

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Handbook of Global Environmental Pollution Series Editors: P. Brimblecombe · R. Lal · R. Stanley · J. Trevors

Bill Freedman Editor

Global Environmental Change

1 3Reference

Handbook of Global Environmental Pollution Series Editors Peter Brimblecombe School of Energy and Environment City University of Hong Kong Kowloon, Hong Kong SAR Rattan Lal Carbon Management and Sequestration Center The Ohio State University, Columbus, OH, USA Roya Stanley Energy Initiatives LLC, Washington DC, USA Jack Trevors University of Guelph School of Environmental Sciences Ontario Agricultural College Guelph, ON, Canada

More information about this series at: http://www.springer.com/series/8130

Bill Freedman Editor

Global Environmental Change With 135 Figures and 28 Tables

Editor Bill Freedman Department of Biology Dalhousie University Halifax, NS, Canada

ISBN 978-94-007-5783-7 ISBN 978-94-007-5784-4 (eBook) ISBN 978-94-007-5785-1 (Print and electronic bundle) DOI 10.1007/978-94-007-5784-4 Springer Dordrecht Heidelberg New York London Library of Congress Control Number: 2014935961 # Springer Science+Business Media Dordrecht 2014 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher’s location, in its current version, and permission for use must always be obtained from Springer. Permissions for use may be obtained through RightsLink at the Copyright Clearance Center. Violations are liable to prosecution under the respective Copyright Law. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com)

Preface

I am pleased to present this volume on Global Environmental Change, which is the first of a multi-volume Springer project titled the Handbook of Global Environmental Pollution. The Handbook provides a comprehensive treatment of environmental pollution and its regional and global effects on both ecosystems and the human economy. Within that context, this first volume provides a series of articles that represent a detailed look at the key aspects of global change, with an emphasis on the causes and consequences of changes in the Earth’s climate system. In their aggregate, the articles in this volume provide detailed information about climate change, its recent anthropogenic forcing, and the profound ecological and socioeconomic outcomes that may result. Our intent is to provide a timely and all-inclusive coverage of the subject matter, in a format that will be useful to environmental professionals, while also being accessible to students in colleges and universities. The development and completion of this volume has been a highly collaborative effort. I particularly applaud the efforts of the subject editors: Ce´lia Alves, Ulisses E.C. Confalonieri, M. Francesca Cotrufo, Brian D. Fath, Ben Kravitz, Roderick J. Lawrence, Marta G. Rivera Ferre, Deborah S. Rogers, Ursula M. Scharler, and R. Jan Stevenson. These dedicated specialists helped to define the topic areas to be covered in individual articles, worked diligently to find suitable authors, and then engaged in an in-depth review process to ensure that the submissions achieved an appropriate coverage of the assigned subject area. In doing their work, the subject editors carried much of the brunt of the work-load for this volume. While their work was intellectually stimulating, it was also difficult and time-consuming, and I am totally grateful and pleased with the accomplishments of the subject editors in all respects. Of course, the essence of the project has resulted from the efforts of the authors of the many articles in this volume. Those persons are all busy professionals; yet they managed to find the time to prepare comprehensive overviews of their subject areas, in a format accessible to a broad field of interested readers. Their work in this respect is exceedingly important to the society, because it helps to inform scientific practitioners, students, and concerned citizens about the most important dimensions of global environmental change. This is perhaps the most consequential field within the larger environmental crisis, and its resolution requires advocacy and

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Preface

decision-making that is well-informed by scientific knowledge – the present volume is a step forward in that respect. Myself, the subject editors, and the many authors who participated in this volume are satisfied to have been a part of a successful academic and scientific endeavor – this was a most worthwhile collaboration for us to have been involved with. May 2014

Bill Freedman

About the Editor

Bill Freedman Department of Biology, Dalhousie University, Halifax, NS, Canada Bill Freedman is an ecologist and environmental scientist. He has taught in the Department of Biology at Dalhousie University, Halifax, Canada, since 1979. His research has examined the influence of environmental stressors, both natural and anthropogenic, on biodiversity, nutrient cycling, and other attributes of ecosystems. Understanding the ecological effects of stressor regimes is of theoretical interest, and it also helps to avoid or repair damages caused by anthropogenic pollution and disturbances. His research has examined the effects of a range of industrial activities, particularly forestry practices, but also acidification, eutrophication, metals, pesticides, and sulphur dioxide. Additional interests include arctic ecology, carbon storage in ecosystems, urban ecology, the design of environmental monitoring programs, and ecologically sustainable resource management. More than one hundred publications in journals have resulted from this work, plus hundreds of book and encyclopedia chapters and research reports. Bill has written or co-authored several books: Environmental Ecology (2nd ed, 1995), Environmental Science: A Canadian Perspective (5th ed, 2010), Ecology: A Canadian Context (2nd ed, 2014), and History of the Nature Conservancy of Canada (2013).

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About the Editor

Bill served on the Board of Directors of the Nature Conservancy of Canada from 1992 to 2012, and was its Chair during 2007–2009. In 2006, he received a Canadian Environment Gold Medal Award from the Canadian Geographic Society, in the category of Community Awards for Conservation. In 2007, he received a Career Achievement Award from the Canadian Council of University Biology Chairs. Bill is an enthusiastic naturalist and traveler, and loves to spend time in wild places.

Section Editors

Global Change and Climate Brian D. Fath Department of Carouge Sciences, Towson University, Towson, MD, USA Global Change and Oceans Ursula M. Scharler School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban, South Africa Global Change and Freshwater Ecosystems R. Jan Stevenson Department of Zoology, Center for Water Sciences, Michigan State University, East Lansing, MI, USA Global Change and Terrestrial Ecosystems M. Francesca Cotrufo Department of Soil and Crop Sciences and Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, USA Urban Environments Ce´lia Alves Centre for Environmental and Marine Studies, Department of Environment, University of Aveiro, Aveiro, Portugal Global Change and Sustainable Development Roderick J. Lawrence Institute for Environmental Sciences, University of Geneva, Carouge, Switzerland Global Change and Human Health Ulisses E. C. Confalonieri LAESA-CPqRR/FIOCRUZ, Belo Horizonte, Brazil

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Section Editors

Global Change and Food Security Marta G. Rivera Ferre Polytechnic School, Environment and Food Department Research Group incl. Societies, Policies and Communities (SoPCi), University of Vic – Central University of Catalonia, Vic, Spain Greenhouse Gases and Geoengineering Ben Kravitz Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA Social Aspects of Global Change Deborah S. Rogers Institute for Research in the Social Sciences (IRiSS), Stanford University, Stanford, CA, USA

Contents

Part I Global Change and Climate Brian D. Fath

..........................

1

1

Global Climate Change, Introduction . . . . . . . . . . . . . . . . . . . . . Natalia Fath and Brian D. Fath

3

2

Radiative Forcing and the Greenhouse Gases . . . . . . . . . . . . . . . David Szpunar

9

3

Reflective Aerosols and the Greenhouse Effect . . . . . . . . . . . . . . Kathryn E. Kautzman

23

4

Water Cycles and Climate Change . . . . . . . . . . . . . . . . . . . . . . . Kevin E. Trenberth

31

5

Global Dimming and Brightening . . . . . . . . . . . . . . . . . . . . . . . . Martin Wild

39

6

Paleoclimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thomas M. Cronin

49

7

Holocene Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Heinz Wanner

55

8

Changes in Atmospheric Carbon Dioxide . . . . . . . . . . . . . . . . . . Hua Lin

61

Global Change and Oceans . . . . . . . . . . . . . . . . . . . . . . . . . .

69

Part II

Ursula M. Scharler 9

Sea-Surface Temperature Thomas M. Smith

..............................

71

10

Variations of Oceanic Heat Content Matthew D. Palmer

......................

77

11

Ocean Currents and Circulation and Climate Change . . . . . . . . Henk A. Dijkstra

85

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Contents

12

Sea Ice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hugues Goosse

97

13

Ocean Acidification and Oceanic Carbon Cycling Dieter A. Wolf-Gladrow and Bjo¨rn Rost

...........

103

14

Other Nutrients and Dissolved Oxygen and Climate Change . . . Katja Fennel

111

15

Marine Net Primary Production . . . . . . . . . . . . . . . . . . . . . . . . . Zoe V. Finkel

117

16

Ecological Carbon Sequestration in the Oceans and Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Richard Sanders and Stephanie Henson

125

17

Ecosystem Resilience and Resistance to Climate Change . . . . . . Bayden D. Russell and Sean D. Connell

133

18

Pelagic Ecosystems and Climate Change . . . . . . . . . . . . . . . . . . . Gregory Beaugrand

141

19

Coral Reefs and Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . David Glassom

151

20

Land-Margin Ecosystems and Global Change Donald F. Boesch

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159

21

Marine Mammals – Natural and Anthropogenic Influences . . . . Martha´n Bester

167

22

Marine Bio-Resources and Climate Change . . . . . . . . . . . . . . . . R. Ian Perry

175

23

Marine Biodiversity and Climate Change . . . . . . . . . . . . . . . . . . Thomas Wernberg, Bayden D. Russell, Mads S. Thomsen, and Sean D. Connell

181

Part III

Global Change and Freshwater Ecosystems

...........

189

R. Jan Stevenson 24

Precipitation Regimes and Climate Change Nathan Moore

................

191

25

Snow, Permafrost, Ice Cover, and Climate Change . . . . . . . . . . Eugenie Euskirchen, Merritt Turetsky, Jonathan O’Donnell, and Ronald P. Daanen

199

26

Glaciers and Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . Regine Hock

205

Contents

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27

Impacts of Projected Changes in Climate on Hydrology David W. Hyndman

......

211

28

Productivity of Freshwater Ecosystems and Climate Change . . . John A. Downing

221

29

Lakes and Climate Change - a Paleoecological Perspective . . . . John P. Smol

231

30

Threats to Freshwater Biodiversity in a Changing World David Dudgeon

.....

243

31

Wetland Ecosystems and Global Change . . . . . . . . . . . . . . . . . . . M. Siobhan Fennessy

255

32

Rivers and Global Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R. Jan Stevenson

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33

Lake Nutrients, Eutrophication, and Climate Change . . . . . . . . John Jones and Michael T. Brett

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34

Acidification, Dissolved Organic Carbon (DOC) and Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mattias Winterdahl, Kevin Bishop, and Martin Erlandsson

Part IV Global Change and Terrestrial Ecosystems . . . . . . . . . . . . M. Francesca Cotrufo

281 289

35

Global Change and Terrestrial Ecosystems, Introduction M. Francesca Cotrufo

.....

291

36

Terrestrial Plant Productivity and Carbon Allocation in a Changing Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Colleen Iversen and Richard Norby

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37

Soil Organic Matter Dynamics, Climate Change Effects Alain Plante and Richard T. Conant

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Soil Trace Gas Emissions and Climate Change . . . . . . . . . . . . . . Klaus Butterbach-Bahl, Eugenio Diaz-Pines, and Michael Dannenmann

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Biogeochemical Cycling in Terrestrial Ecosystems - Individual Components, Interactions and Considerations Under Global Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kristen Freeman and Walter Oechel

40

Distribution of Terrestrial Ecosystems and Changes in Plant Community Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Michael J. Schuster, Lorena Torres Martinez, and Jeffrey S. Dukes

335

341

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Contents

Microbial Community-Level Responses to Warming and Altered Precipitation Patterns Determine Terrestrial Carbon-Climate Feedbacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Matthew D. Wallenstein

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Terrestrial Biodiversity and Climate Change . . . . . . . . . . . . . . . Mark A. Bradford and Robert J. Warren II

355

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Water Deficits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Melinda Laituri

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Desertification and Soil Erosion . . . . . . . . . . . . . . . . . . . . . . . . . . Rattan Lal

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Impacts of Global Change on Crop Production and Food Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Serge Savary, Andrea Ficke, and Clayton A. Hollier

379

Land Management Options for Mitigation and Adaptation to Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Richard A. Houghton

389

Carbon Sequestration in Soil and Vegetation and Greenhouse Gases Emissions Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Keith Paustian

399

46

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Conservation Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Frank Lowenstein and Evan Girvetz

Part V Urban Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ce´lia Alves

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415

49

Global Change and Urban Atmospheres, Introduction . . . . . . . . Erika von Schneidemesser and Paul S. Monks

417

50

Climate–Chemistry Interactions in the Urban Atmosphere . . . . Ivar S. A. Isaksen, O. A. Søvde, Christos Zerefos, and Kostas Eleftheratos

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Climate Change and Air Quality . . . . . . . . . . . . . . . . . . . . . . . . . Anabela Carvalho, Helena Martins, Myriam Lopes, and Ana Isabel Miranda

435

52

Heat Waves, Human Health, and Climate Change . . . . . . . . . . . Aurelio Tobias and Julio Diaz

447

Contents

53

xv

Damage to Materials and Buildings in a Changing Urban Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Peter Brimblecombe

455

54

Urban Biodiversity and Climate Change . . . . . . . . . . . . . . . . . . . Jose Antonio Puppim de Oliveira, Christopher N. H. Doll, Raquel Moreno-Pen˜aranda, and Osman Balaban

461

55

Reducing Emissions of Atmospheric Pollutants . . . . . . . . . . . . . Alexandra Monteiro, Jorge H. Amorim, J. Ferreira, Maria Elisa Sa´, and Carlos Borrego

469

56

Vegetation and Other Development Options for Mitigating Urban Air Pollution Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . Richard Baldauf and David Nowak

57

Urban Vegetation Facing Pollution and Over-Heating . . . . . . . . Elena Paoletti, Ilaria Conese, and Laura Bacci

Part VI

Global Change and Sustainable Development . . . . . . . . .

479 487

497

Roderick J. Lawrence 58

Sustainable Development and Global Change . . . . . . . . . . . . . . . Roderick J. Lawrence

499

59

The Role of Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kornelis Blok

509

60

Kyoto Protocol and Beyond . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Geraldine Pflieger

517

61

Agenda 21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Arthur Lyon Dahl

527

62

Tradable Permits for Greenhouse Gases . . . . . . . . . . . . . . . . . . . Catherine Ferrier

533

63

Taxation of Emissions of Greenhouse Gases . . . . . . . . . . . . . . . . Andrea Baranzini and Stefano Carattini

543

64

Offset Systems and Greenhouse Gases . . . . . . . . . . . . . . . . . . . . . Adrien K. Lawrence

561

65

Population Growth and Global Change . . . . . . . . . . . . . . . . . . . . Bill Freedman

571

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Contents

66

Population Policies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Roderick J. Lawrence

579

67

Economic Growth and Global Change Julien Forbat

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585

68

Building Performance and Climate Change Richard Hyde

................

593

Part VII Global Change and Human Health . . . . . . . . . . . . . . . . . . Ulisses E. C. Confalonieri

597

69

Global Change and Human Health, Introduction . . . . . . . . . . . . Anthony J. McMichael

70

Climate Change, Extreme Weather and Climate Events, and Health Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aderita Sena, Carlos Corvalan, and Kristie Ebi

605

Waterborne and Foodborne Diseases, Climate Change Impacts on Health . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Corinne Schuster-Wallace, Sarah Dickin, and Chris Metcalfe

615

Emerging Infectious Diseases, Vector-Borne Diseases, and Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Madeleine C. Thomson

623

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72

73

Food and Water and Climate Change . . . . . . . . . . . . . . . . . . . . . Colin D. Butler

74

National and Global Monitoring and Surveillance Systems for the Health Risks of Global Change . . . . . . . . . . . . . . . . . . . . . . . Kristie Ebi

75

Health in the ‘Low-Carbon’ Economy . . . . . . . . . . . . . . . . . . . . . Andrew Haines and Paul Wilkinson

Part VIII

Global Change and Food Security . . . . . . . . . . . . . . . . . .

599

629

649 657

665

Marta G. Rivera Ferre 76

Global Change and Food Security, Introduction . . . . . . . . . . . . . Geoffrey Lawrence and Philip McMichael

667

77

Vulnerability of Food Security to Global Change . . . . . . . . . . . . Polly Ericksen

677

78

Impacts of Climate Change on Food Availability: Agriculture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Christoph M€uller

681

Contents

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Impacts of Climate Change on Food Availability: Livestock . . . Feliu Lopez-i-Gelats

80

Impacts of Climate Change on Food Availability: Non-Timber Forest Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sheona Shackleton

695

Impacts of Climate Change on Food Availability: Distribution and Exchange of Food . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Marta G. Rivera Ferre

701

81

689

82

Impacts of Climate Change on Food Accessibility Colin Sage

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709

83

Impacts of Climate Change on Food Utilization . . . . . . . . . . . . . Noora-Lisa Aberman and Cristina Tirado

717

84

Knowledge and Technological Requirements to Adapt to Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Benjamin Graeub, Samuel Ledermann, and Hans R. Herren

725

Agroecology: Adaptation and Mitigation Potential and Policies for Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Janice Jiggins

733

...

745

85

86

The Socioeconomic Capability to Adapt to Climate Change Petra Tschakert

Part IX Greenhouse Gases and Geoengineering . . . . . . . . . . . . . . Ben Kravitz

755

87

The Strategic Value of Geoengineering Research . . . . . . . . . . . . Jane C. S. Long and John G. Shepherd

757

88

Stratospheric Sulfate Aerosols and Planetary Albedo . . . . . . . . . Simone Tilmes and Michael Mills

771

89

Cloud Brightening and Climate Change . . . . . . . . . . . . . . . . . . . Hannele Korhonen and Antti-Ilari Partanen

777

90

Maintaining and Enhancing Ecological Carbon Sequestration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bill Freedman

783

91

Space Sunshades and Climate Change . . . . . . . . . . . . . . . . . . . . . Govindasamy Bala

803

92

Enhancing the Ocean’s Role in CO2 Mitigation Greg H. Rau

.............

817

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Contents

Part X

Social Aspects of Global Change . . . . . . . . . . . . . . . . . . . . .

825

Deborah S. Rogers 93

Social Aspects of Global Change, Introduction . . . . . . . . . . . . . . Deborah S. Rogers

827

94

Defining and Measuring Human Well-Being . . . . . . . . . . . . . . . . David A. Clark

833

95

Vulnerability and Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ben Wisner and Maureen Fordham

857

96

Managing Risk and Responding to the Unknown . . . . . . . . . . . . Ben Wisner and Maureen Fordham

865

97

Pollution and Pollution Control Through an Economic Lens . . . Randall Bluffstone

873

98

Governance Frameworks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Louis Meuleman

885

99

Linguistic and Cultural Homogenization in the Face of Global Change, a Subarctic Example . . . . . . . . . . . . . . . . . . . . . . . . . . . Annette Luttermann

903

100

Human Rights, Rights of the Earth, and Global Change Martin Wagner

......

911

101

Environmental Ethics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Joseph Mazor

925

102

Socioeconomic Equity and Sustainability . . . . . . . . . . . . . . . . . . . Deborah S. Rogers

933

103

Mechanisms of Cultural Change and the Transition to Sustainability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cody T. Ross, Peter J. Richerson, and Deborah S. Rogers

943

Knowledge, Learning, and Societal Change for Sustainability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chris Blackmore

951

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959

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

967

104

105

Engaging Civil Society Robert J. Brulle

Contributors

Noora-Lisa Aberman International Food Policy Research Institute, Washington, DC, USA Jorge H. Amorim Department of Environment, Centre of Environmental and Marine Studies, University of Aveiro, Aveiro, Portugal Laura Bacci Consiglio Nazionale delle Ricerche - Istituto di Biometeorologia (CNR-IBIMET), Firenze, Italy Govindasamy Bala Center for Atmospheric and Oceanic Sciences, Indian Institute of Science, Divecha Center for Climate Change, Bangalore, Karnataka, India Osman Balaban Institute of Advanced Studies, United Nations University, Yokohama, Japan Richard Baldauf U.S. Environmental Protection Agency, Office of Research and Development, and Office of Transportation and Air Quality, Research Triangle Park, NC, USA Andrea Baranzini HEG Gene`ve – School of Management Geneva, University of Applied Sciences and Arts Western Switzerland (HES-SO), Carouge, Geneva, Switzerland Gregory Beaugrand Centre National de la Recherche Scientifique, UMR CNRS LOG 8187, Station Marine, Universite´ des Sciences et Technologies Lille 1, Wimereux, France Martha´n Bester Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Hatfield, South Africa Kevin Bishop Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden Chris Blackmore Communication and Systems Department, The Open University, Milton Keynes, UK Kornelis Blok Department of Science, Technology and Society, Utrecht University, Utrecht, The Netherlands xix

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Contributors

Randall Bluffstone Department of Economics, Portland State University, Portland, OR, USA Donald F. Boesch University of Maryland Center for Environmental Science, Cambridge, MD, USA Carlos Borrego Department of Environment, Centre of Environmental and Marine Studies, University of Aveiro, Aveiro, Portugal Mark A. Bradford School of Forestry and Environmental Studies, Yale University, New Haven, CT, USA Michael T. Brett Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA Peter Brimblecombe School of Energy and Environment, City University of Hong Kong, Kowloon, Hong Kong, China Robert J. Brulle Department of Culture and Communications, Drexel University, Philadelphia, PA, USA Colin D. Butler Faculty of Health, University of Canberra, Canberra, ACT, Australia Klaus Butterbach-Bahl Institute of Meteorology and Climate Research, Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology (KIT), Garmisch-Partenkirchen, Germany Stefano Carattini HEG Gene`ve – School of Management Geneva, University of Applied Sciences and Arts Western Switzerland (HES-SO), Carouge, Geneva, Switzerland Anabela Carvalho Department of Environment and Planning, Centre of Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal David A. Clark Centre of Development Studies, University of Cambridge, Cambridge, UK Richard T. Conant Colorado State University, Fort Collins, CO, USA Ilaria Conese Institute of Plant Protection, National Research Council (CNRIPP), Sesto Fiorentino, Florence, Italy Sean D. Connell Southern Seas Ecology Laboratories, School of Earth & Environmental Sciences, University of Adelaide, Adelaide, SA, Australia Carlos Corvalan Department of Medicine, Pan American Health Organization, Brasilia, Brazil M. Francesca Cotrufo Department of Soil and Crop Sciences and Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, USA

Contributors

xxi

Thomas M. Cronin U.S. Geological Survey, Reston, VA, USA Ronald P. Daanen Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, USA Arthur Lyon Dahl International Environment Forum, Chatelaine, Geneva, Switzerland Michael Dannenmann Institute of Meteorology and Climate Research, Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology (KIT), Garmisch-Partenkirchen, Germany Julio Diaz National School of Public Health, Instituto de Salud Carlos III, Madrid, Spain Eugenio Diaz-Pines Institute of Meteorology and Climate Research, Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology (KIT), Garmisch-Partenkirchen, Germany Sarah Dickin School of Geography and Earth Sciences, McMaster University, Hamilton, ON, Canada United Nations University Institute for Water Environment and Health, Hamilton, ON, Canada Henk A. Dijkstra Department of Physics and Astronomy, Institute for Marine Atmospheric Research Utrecht, Utrecht University, Utrecht, Netherlands Christopher N. H. Doll Institute of Advanced Studies, United Nations University, Yokohama, Japan John A. Downing Iowa State University, Ames, IA, USA David Dudgeon The University of Hong Kong, Hong Kong, China Jeffrey S. Dukes Department of Forestry and Natural Resources, Department of Biological Sciences, Purdue University, West Lafayette, IN, USA Kristie Ebi ClimAdapt, LLC, Los Altos, CA, USA Kostas Eleftheratos Faculty of Geology and Geoenvironment, University of Athens, Greece Polly Ericksen CGiAR and International Livestock Research Institute, Nairobi, Kenya Martin Erlandsson Department of Geography and Environmental Science, School of Human and Environmental Sciences, The University of Reading, Whiteknights, Reading, UK Eugenie Euskirchen Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA

xxii

Contributors

Brian D. Fath Department of Carouge Sciences, Towson University, Towson, MD, USA Natalia Fath Department of Geography and Environmental Planning, Towson University, Towson, MD, USA Katja Fennel Department of Oceanography, Dalhousie University, Halifax, NS, Canada M. Siobhan Fennessy Department of Biology, Kenyon College, Gambier, OH, USA J. Ferreira Department of Environment, Centre of Environmental and Marine Studies, University of Aveiro, Aveiro, Portugal Catherine Ferrier Geneva School of Economics and Management, University of Geneva, Geneva, Switzerland Andrea Ficke Bioforsk Plantehelse, Bioforsk Plant Health and Plant Protection, ˚ s, Norway A Zoe V. Finkel Environmental Science Program, Mt Allison University, Sackville, NB, Canada Julien Forbat Institute of Environmental Sciences, University of Geneva, Carouge, Switzerland Maureen Fordham Department of Geography, Northumbria University, Newcastle-Upon-Tyne, UK Bill Freedman Department of Biology, Dalhousie University, Halifax, NS, Canada Kristen Freeman Global Change Research Group, San Diego State University, San Diego, CA, USA Evan Girvetz International Center for Tropical Agriculture, Nairobi, Kenya David Glassom University of KwaZulu-Natal, Durban, South Africa Hugues Goosse Centre de recherches sur la terre et le climat Georges Lemaıˆtre, Earth and Life Institute, Universite´ Catholique de Louvain, Louvain, Belgium Benjamin Graeub Biovision Foundation for Ecological Development, Zurich, Switzerland Andrew Haines London School of Hygiene and Tropical Medicine, London, UK Stephanie Henson National Oceanography Centre, University of Southampton, Southampton, UK Hans R. Herren Millennium Institute, Washington, DC, USA Biovision Foundation, Zurich, Switzerland

Contributors

xxiii

Regine Hock Geophysical Institute, University of Alaska, Fairbanks, AK, USA Clayton A. Hollier Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, USA Richard A. Houghton Woods Hole Research Center, Falmouth, MA, USA Richard Hyde Faculty of Architecture, Design and Planning, The University of Sydney, Sydney, NSW, Australia David W. Hyndman Department of Geological Sciences, Michigan State University, East Lansing, MI, USA Ivar S. A. Isaksen Department of Geosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway Center for International Climate and Environmental Research – Oslo (CICERO), Oslo, Norway Colleen Iversen Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA Janice Jiggins Knowledge, Technology and Innovation Section, Communication, Philosophy, Technology (CPT), Wageningen University, Wageningen, The Netherlands John Jones Department of Fisheries and Wildlife Sciences, University of Missouri, Columbia, MO, USA Kathryn E. Kautzman Department of Chemistry, Towson University, Towson, MD, USA Hannele Korhonen Finnish Meteorological Institute, Kuopio, Finland Melinda Laituri Department of Ecological Science and Sustainability, Colorado State University, Fort Collins, CO, USA Rattan Lal Carbon Management and Sequestration Center, The Ohio State University, Columbus, OH, USA Adrien K. Lawrence Swiss Academy of Sciences (SCNAT), Bern, Switzerland Geoffrey Lawrence The University of Queensland, Brisbane, Australia Roderick J. Lawrence Institute for Environmental Sciences, University of Geneva, Carouge, Switzerland Samuel Ledermann Biovision Foundation for Ecological Development, Zurich, Switzerland Hua Lin Chinese Academy of Sciences, Mengla, Yunnan, China Jane C. S. Long Bipartisan Policy Center and the Environmental Defense Fund, Oakland, CA, USA

xxiv

Contributors

Myriam Lopes Department of Environment and Planning, Centre of Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal Feliu Lopez-i-Gelats Center for Agro-food Economy and Development (CREDA-UPC-IRTA), Castelldefels, Barcelona, Spain Frank Lowenstein New England Forestry Foundation, Littleton, MA, USA Annette Luttermann Golden, BC, Canada Helena Martins Department of Environment and Planning, Centre of Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal Joseph Mazor Department of Philosophy, London School of Economics and Political Science, London, UK Anthony J. McMichael National Centre for Epidemiology and Population Health, The Australian National University, Canberra, Australia Philip McMichael Cornell University, Ithaca, NY, USA Chris Metcalfe Trent University and United Nations University, Peterborough, ON, Canada Louis Meuleman VU University Amsterdam, Amsterdam, The Netherlands Public Strategy for Sustainable Development, Brussels, Belgium Michael Mills National Center for Atmospheric Research, Boulder, CO, USA Ana Isabel Miranda Department of Environment and Planning, Centre of Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal Paul S. Monks Department of Chemistry, University of Leicester, Leicester, UK Alexandra Monteiro Department of Environment, Centre of Environmental and Marine Studies, University of Aveiro, Aveiro, Portugal Nathan Moore Department of Geography, Michigan State University, East Lansing, MI, USA Raquel Moreno-Pen˜aranda Institute of Advanced Studies, United Nations University, Yokohama, Japan Christoph M€ uller Potsdam Institute for Climate Impact Research, Potsdam, Germany Richard Norby Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA

Contributors

xxv

David Nowak U.S. Department of Agriculture, Forest Service, Northern Research Station, Syracuse, NY, USA Jonathan O’Donnell U.S. Geological Survey, Boulder, CO, USA Walter Oechel Global Change Research Group, San Diego State University, San Diego, CA, USA Matthew D. Palmer Met Office Hadley Centre, Exeter, UK Elena Paoletti Istituto per la Protezione delle Piante (IPP), Consiglio Nazionale delle Ricerche (CNR), Sesto Fiorentino, Florence, Italy Antti-Ilari Partanen Finnish Meteorological Institute, Kuopio, Finland Keith Paustian Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA R. Ian Perry Fisheries & Oceans Canada, Nanaimo, BC, Canada Geraldine Pflieger De´partement de Science Politique et Relations Internationals, Institut des Sciences de l’environnement, Universite´ de Gene`ve, Gene`ve, Switzerland Alain Plante Department of Earth & Environmental Science, University of Pennsylvania, Philadelphia, PA, USA Jose Antonio Puppim de Oliveira United Nations University Institute of Advanced Studies (UNU-IAS), 6F International Organizations Center, Yokohama, Japan Greg H. Rau Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA Peter J. Richerson Department of Environmental Science and Policy, University of California, Davis, CA, USA Marta G. Rivera Ferre Polytechnic School, Environment and Food Department Research Group incl. Societies, Policies and Communities (SoPCi), University of Vic – Central University of Catalonia, Vic, Spain Deborah S. Rogers Institute for Research in the Social Sciences (IRiSS), Stanford University, Stanford, CA, USA Cody T. Ross University of California, Davis, CA, USA Bjo¨rn Rost Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany Bayden D. Russell Southern Seas Ecology Laboratories, School of Earth & Environmental Sciences, University of Adelaide, Adelaide, SA, Australia

xxvi

Contributors

Maria Elisa Sa´ Department of Environment, Centre of Environmental and Marine Studies, University of Aveiro, Aveiro, Portugal Colin Sage Department of Geography, University College Cork, Cork, Ireland Richard Sanders National Oceanography Centre, University of Southampton, Southampton, UK Serge Savary UMR AGIR, INRA, Castanet Tolosan, France Michael J. Schuster Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, USA Corinne Schuster-Wallace Institute for Water, Environment and Health, United Nations University, Hamilton, ON, Canada Aderita Sena Ministry of Health, Brasilia, Brazil Sheona Shackleton Department of Environmental Science, Rhodes University, Grahamstown, South Africa John G. Shepherd University of Southampton, Southampton, UK Thomas M. Smith NOAA, SCSB, STAR, NESDIS, College Park, MD, USA John P. Smol Queen’s University, Kingston, ON, Canada O. A. Søvde Center for International Climate and Environmental Research - Oslo (CICERO), Oslo, Norway R. Jan Stevenson Department of Zoology, Center for Water Sciences, Michigan State University, East Lansing, MI, USA David Szpunar Roosevelt University, Chicago, IL, USA Mads S. Thomsen Marine Ecology Research Group, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand Madeleine C. Thomson International Research Institute for Climate and Society, The Earth Institute, and Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA Simone Tilmes National Center for Atmospheric Research, Boulder, CO, USA Cristina Tirado PAHO/WHO, Rio de Janeiro, Brazil UCLA School of Public Health Aurelio Tobias Institute of Environmental Assessment and Water Research (IDAEA), Barcelona, Spain Lorena Torres Martinez Department of Biological Sciences, Purdue University, West Lafayette, IN, USA

Contributors

xxvii

Kevin E. Trenberth National Center for Atmospheric Research, Boulder, CO, USA Petra Tschakert Department of Geography and the Earth and Environmental Systems Institute (EESI), Pennsylvania State University, University Park, PA, USA Merritt Turetsky Department of Integrative Biology, University of Guelph, Guelph, ON, Canada Erika von Schneidemesser Atmospheric Chemistry Group, University of Leicester, Leicester, UK Martin Wagner International Program, Earthjustice, San Francisco, CA, USA Matthew D. Wallenstein Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, USA Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO, USA Heinz Wanner Oeschger Centre, University of Bern, Bern, Switzerland Robert J. Warren II School of Forestry and Environmental Studies, Yale University, New Haven, CT, USA Department of Biology, SUNY Buffalo State, Buffalo, NY, USA Thomas Wernberg The University of Western Australia, UWA Oceans Institute and School of Plant Biology, Australian Institute of Marine Science, Crawley, WA, Australia Martin Wild Eidgeno¨ssiche Technische Hochschule (ETH) Zurich, Institute for Atmospheric and Climate Science, Zurich, Switzerland Paul Wilkinson London School of Hygiene and Tropical Medicine, London, UK Mattias Winterdahl Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden Ben Wisner Aon-Benfield Hazard Research Centre, University College London, London, UK Dieter A. Wolf-Gladrow Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany Christos Zerefos Biomedical Research Foundation, Academy of Athens, Athens, Greece

Part I Global Change and Climate Brian D. Fath

1

Global Climate Change, Introduction Natalia Fath and Brian D. Fath

Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Temperature Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oceans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cryosphere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sea Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Extreme Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3 4 4 5 6 7 7 7

Abstract

The issue of global climate change is not new, but over the past few decades, the conversation has spilled out of the academic halls and research conferences into policy and public discussions. The goal of this section titled Global Change and Climate is to provide an overview of some of the key scientific concepts surrounding this topic. We begin with a summary overview of the major processes effecting global climate change. Keywords

Climate change • Cryosphere • Oceans • Sea level rise • IPCC

N. Fath (*) Department of Geography and Environmental Planning, Towson University, Towson, MD, USA e-mail: [email protected] B.D. Fath Department of Carouge Sciences, Towson University, Towson, MD, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_46, # Springer Science+Business Media Dordrecht 2014

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N. Fath and B.D. Fath

Introduction Climate refers to the long-term weather patterns, and change is the statistical deviation of these observed weather conditions. The change may be detected at various scales, local, regional, or global, but here we focus on change at the global scale. Broadly speaking the term does not imply the cause of the change, and clearly the planet has experienced climate changes throughout geologic time as a result of Earth’s natural processes. However, here, specific attention is paid to anthropogenic global change occurring during the past century. Although climate is determined by a complex set of interrelations involving solar insolation, the properties of the receiving surface, and the composition of transfer medium (atmosphere), a fairly simple energy balance can be constructed. The greenhouse gases retain the outgoing energy radiated from the Earth’s surface, reradiating it back to the Earth and eventually to space. The net result is more heat retained in the Earth-atmosphere system, which drives different climatic factors. The causes of change are described in more detail in the entry on the greenhouse effect. Evidence of a changing global climate can be observed in terms of several factors including rising global average temperature, warming oceans, ocean acidification, shrinking ice sheets, glacial retreat, declining Arctic sea ice, rising sea level, and extreme events.

Temperature Change The most common attribute of climate is temperature. Globally, we observe a rise of 0.8 C since 1880, and the period from January 2000 to December 2009 was the warmest decade on record. Figure 1.1 shows the agreement in rise of global surface temperatures from four independent records. Temperatures are expected to continue to rise due to increased GHG loading. Estimates are that by 2100 the temperature could be 3–5 C above the preindustrial baseline (IPCC 2007).

Oceans The heat capacity, or ability to retain energy, of air is much lower than that of water (1.012 vs. 4.1813, respectively). Therefore, a changing climate would have more noticeable effects on the air, but also a detectable change in the ocean temperatures is possible. The amount of additional energy required to raise ocean temperatures, on one hand acts as a buffer to atmospheric temperature changes, but on the other demonstrates the large impact that climate change is having. In other words, oceans are absorbing much of the increased energy in the Earth-atmosphere system. Measurements indicate that the ocean surface (top 700 m) has warmed by 0.168 C F since 1969 (Levitus et al. 2009). The ocean is a sink not only for the heat but also for the carbon gases being loaded into the atmosphere. As a sink, the

1

Global Climate Change, Introduction

5

Global Surface Temperatures Four independent records show nearly identical long-term warming trends.

0.6

Temperature Anomaly (°C)

0.4

NASA Goddard Institute for Space Studies Met Office Hadley Centre/Climatic Research Unit NOAA National Climatic Data Center Japanese Meteorological Agency

0.2 0 −0.2 −0.4 −0.6 1880

1900

1920

1940 Year

1960

1980

2000

Fig. 1.1 Record of global surface temperatures for four independent sources showing warming trend (credit: NASA Earth Observatory/Robert Simmon)

oceans help to reduce the overall GHG concentration in the atmosphere thus ameliorating somewhat the climate impacts. In fact, the oceans absorb around 2 billion tons of CO2 per year (Sabine et al. 2004). However, this carbon is having another effect on the oceans in that once converted to carbonic acid acts to increase the acidity of the oceans by lowering the pH. A 30 % increase in the ocean acidity has been observed since the beginning of industrial revolution.

Cryosphere Increasing temperatures are having an observable effect on the cryosphere. Ice mass is being lost in the polar and mountain regions at an accelerating rate. The two main ice sheets on Earth, in Antarctica and Greenland, have both decreased substantially in mass. Based on data from NASA’s Gravity Recovery and Climate Experiment (GRACE), Greenland lost 150–250 km3 of ice per year between 2002 and 2006, while Antarctica lost about 152 km3 of ice between 2002 and 2005 (Fig. 1.2). Glaciers are retreating almost everywhere around the world including the Alps, Himalayas, Andes, and Rockies as these regions face greater temperature changes. Figure 1.3 shows the retreating glaciers and formation of glacial lakes in the Bhutan-Himalaya region. Although not land-based ice, contributing to sea-level rise, the Arctic sea ice is also declining, reaching its lowest level on record in 2011. Currently, it is losing about 12 % per decade.

6

N. Fath and B.D. Fath

1000 800

ICE MASS CHANGE (Gt)

600 400 200 0 −200 −400 −600 −800 −1000

2003

2004

2005

2006

2007

2008

2009

CALENDAR YEAR

Fig. 1.2 Ice mass change in Antarctica from NASA’s GRACE satellite

Fig. 1.3 This NASA image shows receding glaciers and the formation of glacial lakes in BhutanHimalaya

Sea Level The combination of warmer oceans, melting ice sheets, and glaciers contributes overall to the rise in sea level – another clear indication of global climate change.

1

Global Climate Change, Introduction

7

During the twentieth century, the sea level rose about 17 cm but with an increasing rate during the past decades. Currently, sea level is measured at a rise of 3.19 mm per year. Even at this pace, by century’s end there would be another 0.3 m rise in sea level. Low-lying areas are greatly affected by this consequence as many human settlements are on coastal areas.

Extreme Events The world has also experienced an increase in the number of extreme events. These include record number of high-temperature events, intense rainfalls, or devastating droughts, hurricane, and tornado activity. There is less direct evidence that they are the result of climate change, but their occurrence is consistent with a warming world in which more energy in the system is dissipated through large atmospheric processes.

Conclusions Signs of change, discussed above, are documented in numerous scientific reports. Overwhelming evidence supports the conclusion that the anthropogenic driver is behind the rapid global climate change experienced recently. Uncertainties exist in projections of how global climate change will evolve in the future. However, the fundamental conclusions about the processes and the problem of climate change are solid.

References IPCC (2007) Fourth Assessment Report: Climate Change 2007. Working Group I: The Physical Science Basis Levitus S et al (2009) Global ocean heat content 1955–2008 in light of recently revealed instrumentation problems. Geophys Res Lett 36:L07608 Sabine CL et al (2004) The oceanic sink for anthropogenic CO2. Science 305:367–371 Velicogna I (2009) Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE. Geophys Res Lett 36:L19503

2

Radiative Forcing and the Greenhouse Gases David Szpunar

Contents Definition and Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Derivation of a Simple Climate Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Abstract

The idea of radiative forcing is introduced through the development of a simple climate model using energy balance with a system composed of the Sun, Earth, and a thin atmospheric layer. A brief discussion of climate forcing agents in general is followed by the specific case of forcing due to an increase in greenhouse gas concentrations. Keywords

Climate change • Radiative forcing • Forcing agent • Greenhouse gas • Climate sensitivity

Definition and Introduction This section will introduce some definitions and concepts necessary before a simple model describing Earth’s temperature is derived. This model will be used to introduce the concept of radiative forcing and how it is related to changes in the Earth’s average temperature. The temperature of the Earth (like all things) is subjected to the first law of thermodynamics, which states that energy is conserved. We can liken this energy conservation to a bank account. Money can change forms (e.g., checking

D. Szpunar Roosevelt University, Chicago, IL, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_70, # Springer Science+Business Media Dordrecht 2014

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and saving accounts), but the total amount of money is governed by Nature’s accountant: the first law of thermodynamics. Energy received by the Earth from the Sun can change form, but it must all be accounted for. To work with the first law, we must keep track of all the energy in our system – the Sun-Earth pair. As we will discover shortly, both the Sun and the Earth radiate energy in the form of light. The energy arriving from the Sun does not necessarily have to equal the energy released from the Earth at any one time. However, for the Earth’s temperature to be stable, the energy received from the Sun as light must be balanced by the energy emitted by the Earth as light over a long period of time (on average) (Archer and Rahmstorf 2010). Due to this energy balance, whatever energy is taken in, the same amount must be emitted. This energy may be of different wavelengths, but it must be the same total amount. Because we are “bookkeeping” energy, we must address how to measure this energy input/output. We could simply use energy in terms of Joules (1 J ¼ 1 kgm2s2). However, this does not necessarily tell the whole story. We may sometimes want to know the amount of energy transferred in a given amount of time. A certain amount of energy transferred over a long period of time will not have the same effect as the same amount of energy transferred over a short period of time. Measuring the amount of energy in Joules in a given time period (e.g., seconds, s) is simply power measured in Watts (1 W ¼ 1 J/s). It is the rate energy that is transferred. Finally, knowing the energy transferred over a given period of time still neglects the area over which the energy is transferred. Energy transferred over a small area will have a much greater effect than the same amount transferred over a larger area. We can measure the power of the energy transferred per unit area, which is known as a flux (units ¼ W/m2). Now that we have addressed the different ways to measure energy, the next question is, “What is light, and how does it affect energy balance?” Light is a form of electromagnetic radiation: a periodic disturbance (wave) in the omnipresent electric and magnetic fields. In classical electrodynamics, a charge that is accelerated produces a change in the electric and magnetic fields that reproduces itself, resulting in an electromagnetic wave. We now consider some properties of these waves. Waves in general are characterized by several factors. The first is the speed at which they propagate, which for electromagnetic waves is the speed of light (c ¼ 2.998  108 m/s in vacuum). The second defining characteristic of a wave is how quickly the wave oscillates. This is known as frequency (n) and can be thought of as the number of cycles the wave undergoes per unit time. Usual units are given in Hertz (1 Hz ¼ 1 s1). Finally, the distance between two identical points on a wave is known as the wavelength, l. The relationship between these three factors is: c ¼ nl

(2:1)


speed ¼ ðfrequency Þðwavelength   1 m=s ¼ ðm Þ s

(2:2)

Notice the units are consistent:

2

Radiative Forcing and the Greenhouse Gases

11 ← Increasing Frequency (ν)

1024

1022

1020

γ rays

1018

1016

X rays

1014

UV

1012

IR

1010

108

Microwave FM

106

104

102

100 ν (Hz)

Long radio waves

AM

Radio waves

10−16

10−14

10−12

10−10

10−8

10−6

10−4

10−2

100

102

104

106

108

λ (m)

Increasing Wavelength (λ) → Visible spectrum

400

500

600

700

Increasing Wavelength (λ) in nm →

Fig. 2.1 A schematic showing ranges of the electromagnetic spectrum. The inset from approximately 400 nm to 700 nm constitutes the visible range

In the early twentieth century, it was found that, under the right circumstances, electromagnetic radiation could also be thought of as a particle since termed a photon. Each photon carries with it a discrete amount of energy, which is dependent on the frequency of the light (and therefore wavelength) through the equation E ¼ hn ¼ h

 c l

(2:3)

where E is the energy of the photon, h is Planck’s constant (h ¼ 6.6261034 Js), c is the speed of light (c ¼ 2.998  108 m/s), n is frequency of oscillation of the light, and l is the wavelength of the light. Note here that the energy of light is inversely proportional to wavelength and spans a much longer range than the visible range we are accustomed to (see Fig. 2.1). The visible region of light is bookended by the infrared (IR) on the low-energy side and the ultraviolet (UV) on the high-energy side. Consider a substance of N particles, some of which are charged. Bodies at a temperature above absolute zero (T > 0 K) will be moving with a range of velocities, the average of which is related to the substance’s temperature. For example, the average kinetic energy of a monatomic (1 atom) ideal gas is given by Τ ¼ 3/2kBT, where kB ¼ 1.381023 JK1 is Boltzmann’s constant. In essence, the faster the particles move, the higher the temperature. This motion is random, and any changes in velocity correspond to an acceleration. Remember that from classical electrodynamics, a charged particle undergoing acceleration emits energy as an electromagnetic wave. The higher the temperature, the greater the amount of energy that is released. This is manifested in the wavelength of emitted light through Eq. 2.3.

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D. Szpunar

Thus, all objects over T ¼ 0 K will emit electromagnetic radiation, the frequency (and therefore the wavelength) governed by the body’s temperature. As already stated, however, the particles’ velocities are random, with their average value corresponding to a particular temperature. Thus, we should expect a distribution of wavelengths, l emitted from an object. We will consider a hypothetical object that absorbs all wavelengths perfectly (i.e., with 100 % efficiency) and is a perfect emitter of radiation as well, known as a blackbody. The distribution of wavelengths emitted by a blackbody is given by fbl ðT Þ ¼

2phc2  hc 
1 l exp kTl 5

(2:4)

where h is Planck’s constant, c is the speed of light, kB is Boltzmann’s constant, T is temperature in Kelvin, and l is wavelength (Jacob 1999). Here, fbl is a flux per unit wavelength and is given the superscript “b” to signify this is for a blackbody, while “l” signifies this is the flux at a given wavelength. However, we are interested in the total energy, rather than just at a particular wavelength, so we need to sum up the value of fbl , for each individual range of wavelengths, Dl. In the limit of Dl ! 0, this sum becomes an integral. This integral of fbl over all wavelengths is the total radiation flux emitted by a blackbody and is equal to FT ¼ sT 4

(2:5)

where s ¼ 5.67  108 Wm2 K4 is the Stefan-Boltzmann constant (Jacob 1999). Blackbodies, however, are idealized objects. Real objects do not absorb and emit all frequencies with 100 % efficiency. We can modify Eq. 2.4 to account for this fact, using Kirchhoff’s Law. If an object absorbs radiation at a particular wavelength l with an efficiency el, then it will also emit radiation of wavelength l at the same efficiency (el) relative to a perfect blackbody. Thus, fl ðT Þ ¼ el ðT Þsbl ðT Þ

(2:6)

where sbl (T) is given by Eq. 2.4 (Jacob 1999). If we record the intensity of light emitted by the Sun as a function of wavelength (a solar emission spectrum), then we see that it agrees with that of a blackbody with a temperature of 5,800 K (see Fig. 2.2). Here, the dotted line is the flux distribution of a blackbody at 5,800 K, and the solid line is the actual experimental solar emission spectrum. We therefore approximate the Sun as a blackbody at the temperature 5,800 K. The Earth is at a temperature above 0 K and therefore also emits radiation. The Earth is obviously at a much lower temperature than the Sun and, therefore, emits at longer wavelengths.

2

Radiative Forcing and the Greenhouse Gases

13

Sun’s Spectrum vs. Thermal Radiator of a single temperature T = 5777 K 2.5 spectrum of Sun spectrum of T = 5777 K blackbody

Obs. “Intensity” (W/m2/nm)

2

1.5

1

0.5

0

200

400

600

800

1200 1000 wavelength (nm)

1400

1600

1800

2000

Fig. 2.2 The spectral output of the Sun as a function of wavelength. The smooth curve is a fit to the data modeling the Sun as a blackbody radiator with a temperature of 5777K

Derivation of a Simple Climate Model Now that we have introduced the necessary terms, we are ready to develop a simple climate model to describe the Earth’s temperature and ultimately the concept of radiative forcing. This model is closely based off the treatment of D. Jacob in Introduction to Atmospheric Chemistry (Jacob 1999). We began this chapter with a discussion of the first law of thermodynamics, and we are now in the position to return to it. Let us now consider our energy source – the Sun. The energy transfer from the Sun is initiated via nuclear reactions, which result in the emission of electromagnetic radiation characterized by the blackbody emission spectrum (Eq. 2.4). A portion of this energy impinges on the Earth. The (mostly) visible light emitted by the Sun is absorbed by the Earth, which causes it to heat up. This absorption of energy as heat results in an increase of temperature at the Earth’s surface, causing the emission of IR radiation from the Earth’s surface. We can effectively see Earth as changing the wavelength from the visible to the infrared range (see Fig. 2.3). Eventually, the energy impinging on the Earth’s surface is exactly balanced by its own emission. The temperature of the Earth is then stable and defined by this thermal equilibrium.

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D. Szpunar

Fig. 2.3 The spectral output of the Sun (on left) compared to that of the Earth (on right). Note that while the Sun’s output peaks in the visible region, the Earth’s radiation peaks in the infrared range

The total energy emitted from the Sun per unit time is simply the flux emitted (sTs4) multiplied by the total surface area of the Sun (4pRs2 where Rs is the radius of the Sun): Es ¼ 4pRs 2 sT s 4 This should be evident because: Power ¼ ðfluxÞðareaÞ ¼

(2:7)

  Power ðareaÞ area

As we move further and further from the Sun, the flux drops. This is because the light spreads out in a sphere of increasing radius as it is emitted by the Sun. If a point is located at a distance d from the Sun, then it spreads out proportionally to the surface area of the “light sphere,” 4pd2. If we want the flux at a distance d from the Sun, we divide the total energy emitted by the Sun (Eq. 2.7) by the total surface area of the “light sphere,” 4pd2. Fs ¼

Es 4pRs sT s 4 ¼ 4pd2 4pd2 2 4 Rs sT s ¼ d2

(2:8)

Substituting known values into Eq. 2.8 gives Fs ¼ 1,370 Wm2, which is known as the solar constant (Jacob 1999).

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Radiative Forcing and the Greenhouse Gases

Fig. 2.4 Schematic showing the cross -sectional area of the Earth that is available to solar radiation

15 Area = pRE2

Earth

Sun

Now that we have the total flux hitting the Earth at a distance d from the Sun, we want to convert that to a total energy. Here, we must recognize that out of the total “light sphere” emitted from the Sun, only a disc of area pRE2 (RE ¼ radius of the Earth) of the Sun’s radiation is available to the Earth at any one time (see Fig. 2.4). Thus, the total energy impinging on the Earth’s surface is: Fs pRE 2

(2:9)

Equation 2.9 gives the total energy striking the Earth per unit time. However, this total power does not tell the whole story. We once again must consider the flux of radiation striking the Earth. We therefore divide the total power striking the Earth divided by the total surface area of the Earth, 4pRE2: Fs pRE 2 4pRE 2 Fs ¼ 4

Fsun ¼

(2:10)

This equation represents the flux of radiation emitted from the Sun available to the Earth and assumes that all of the light impinging on the Earth actually strikes its surface and is absorbed. This is not always the case, however, because some of this radiation is scattered (reflected) back into space by clouds, snow, ice, etc. This fraction of light that is reflected is known as the planetary albedo, A, which for the Earth is A ¼ .28. Note albedo is dimensionless. Because A is the fraction of light reflected, 1-A is the fraction of light that actually strikes the Earth and is absorbed. Therefore, Eq. 2.10 becomes: Fsun ¼

Fs ð1  AÞ 4

(2:11)

We once again return to the first law and the concept of thermal equilibrium. The energy absorbed by the Earth results in a heating, which in turn causes the Earth to radiate primarily in the infrared. Although the Earth is not actually a blackbody, we will approximate it as one here. Thus, the radiation flux emitted by the Earth is

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D. Szpunar

FE ¼ sT E 4

(2:12)

where TE is the temperature of the Earth, the quantity we are interested in. Because this energy must be balanced, whatever flux strikes the Earth from the Sun must be exactly equal to the flux emitted from the Earth back to space. In other words, Fsun ¼ FE Fs ð1  AÞ ¼ sT E 4 4

(2:13)

where we have equated Eqs. 2.11 and 2.12.3 Solving for TE gives: 

Fs ð1  AÞ TE ¼ 4s

1=4 (2:14)

Substituting the known values into Eq. 2.14 gives a temperature of the Earth of TE ¼ 255 K (Jacob 1999). Although this is a surprisingly low temperature, we should recognize that the actual properties of the atmosphere were not taken into account in this model. The reason the atmosphere must be taken into account is because, as shown in chapter ▶ Soil Trace Gas Emissions and Climate Change, trace gases in the atmosphere are capable of absorbing radiation in the IR (i.e., greenhouse gases), exactly the range of the electromagnetic spectrum where the Earth emits. This obviously upsets the equilibrium situation that enabled the formulation of the temperature relation (Eq. 2.14). We will therefore alter our model to include the atmosphere, approximating it as a thin layer that absorbs in the IR. The atmosphere does not appreciably absorb in the visible, which is evidenced by the lack of color in the atmospheric gases. Because the peak as well as majority of the output from the Sun is in the visible (see Fig. 2.3), we will assume here that the atmosphere is completely transparent to solar radiation. However, because the Earth radiates in the IR (see Fig. 2.3), this outgoing radiation can be absorbed by the Earth’s atmosphere. We will denote the fraction of outgoing radiation that is absorbed as f. Because the atmosphere is taken to be a separate component, we will denote its temperature as T1 and the temperature of the Earth’s surface as T0. Because the atmospheric layer is transparent to solar radiation, we will only consider the outgoing radiation from the Earth (terrestrial radiation). The flux of terrestrial radiation absorbed by the atmosphere is the terrestrial output (Eq. 2.12) multiplied by the fraction that absorbs f: Fa ¼ f sT 0 4

(2:15)

Because the fraction of light that escapes the atmosphere is 1  f, the flux of terrestrial radiation escaping the atmosphere is:

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Radiative Forcing and the Greenhouse Gases

17

ð1  f ÞsT 0 4

(2:16)

We must also consider, however, the fact that the atmospheric layer can also radiate energy with an outgoing contribution of: Fa ¼ f sT 1 4

(2:17)

due to Kirchhoff’s law. Note the inclusion of f, which acts as the absorption efficiency, e, in Eq. 2.6. Equations 2.16 and 2.17 are then added to Eq. 2.13 to give its modified form: F s ð 1  AÞ ¼ ð1  f ÞsT 0 4 þ f sT 1 4 4

(2:18)

Equation 2.18 has two unknowns (T0 and T1), making a unique solution impossible. However, we can also construct an equation governing the atmospheric layer and its equilibrium with the Earth. This layer can radiate out to space ( fsT14) as well as back down to Earth ( fsT14) and therefore has a total flux of 2fsT14. The atmospheric layer must balance with the Earth, and therefore, the equation is: f sT 0 4 ¼ 2f sT 1 4

(2:19)

Next, we solve for T14 in terms of T04 in Eq. 2.19 giving: T 0 4 =2 ¼ T 1 4

(2:20)

Substituting Eq. 2.20 into Eq. 2.18 gives: Fs ð 1  AÞ T04 ¼ ð1  f ÞsT 0 4 þ f s ¼ ð1  f =2ÞsT 0 4 4 2

(2:21)

Solving for T0, the surface temperature of the Earth, gives:  T0 ¼

Fs ð 1  AÞ 4sð1  f =2Þ

1=4 (2:22)

A value of f ¼ 0.77 gives the best agreement with the observed temperature of 288 K. Thus, about 80 % of outgoing terrestrial radiation is absorbed by the atmosphere resulting in the natural greenhouse effect (American Chemical Society 2009). This effect is termed the natural greenhouse effect because it is a naturally occurring physical phenomenon, without which the Earth would have an average temperature below freezing. The enhanced greenhouse effect is due to changes in the atmospheric composition that increases the absorption over 80 %

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D. Szpunar

Radiative forcing of climate between 1750 and 2005 Radiative Forcing Terms CO2 Long-lived greenhouse gases

N2O CH4 Halocarbons

Human activities

Ozone

Stratospheric (−0.05)

Tropospheric

Stratospheric water vapour Black carbon on snow

Land use

Surface albedo Direct effect Total Aerosol Cloud albedo effect

Natural processes

Linear contrails

(0.01)

Solar irradiance Total net human activities −2

−1

0

1

2

Radiative Forcing (watts per square matre) Fig. 2.5 Radiative forcing of different agents along with their uncertainty

(American Chemical Society 2009). An increase in greenhouse gas (GHG) concentration is but one example of climate forcing. Other examples include changing the intensity of the solar output and changing of albedo due to snow, ice, and clouds (to be covered in Chapter X). In general, the factors that can change the Earth’s temperature through a disturbance in the Earth-Sun radiation balance are called climate forcing agents, and the strength of forcing in W/m2 is termed radiative forcing (RF). Different RF values can have different overall effects on the temperature. For example, GHGs, because of their long atmospheric lifetimes, have global effects, while aerosols with their relatively short atmospheric lifetimes have local effects. Figure 2.5 shows the radiative forcing from the major agents and their corresponding uncertainties.

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Radiative Forcing and the Greenhouse Gases

19

Inspection of Eq. 2.22 shows how radiative forcing will affect the Earth’s surface temperature, T0. An increase/decrease in solar intensity will increase/decrease Fs and therefore increase/decrease T0. An increase in albedo from increased cloud cover or a volcanic eruption increases A, resulting in a lowering of T0, while a reduction in albedo results in an increase of T0. Finally, an increase in GHG concentration will result in an increase in f, ultimately resulting in an increase in T0. We will now examine in more detail radiative forcing through an increase in GHG concentration. It is understood here that the RF of a GHG is defined to be the value under clear sky conditions (Archer and Rahmstorf 2010). Consider our system at radiative equilibrium. An injection of GHG will upset this equilibrium. If a mass Dm of GHG X is added to the atmosphere, while keeping everything else, including temperature, constant, the increase in GHG concentration results in an increase in terrestrial radiation absorption by the atmosphere and therefore a reduction in the outgoing flux of radiation from the top of the atmosphere by DF (in Wm2). This change in flux, DF, is defined as the radiative forcing. Remember from Eq. 2.19 the outgoing flux is given by: ð1  f ÞsT 0 4 þ ð f =2ÞsT 0 4 ¼ ð1  f =2ÞsT 0 4

(2:23)

An increase in GHG concentration results in an increase in absorption efficiency which we will denote Df. Including this new absorption contribution in Eq. 2.23 gives a new outgoing flux given by:  1

  f þ Df sT 0 4 2

(2:24)

Remember that radiative forcing (DF) is defined as the difference in forcing (Wm2) between the forcing with and without the forcing agent. We therefore subtract Eq. 2.24 from Eq. 2.23: 

  f þ Df DF ¼ ð1  f =2ÞsT 0  1  sT 0 4 2 Df sT 0 4 ¼ 2 4

(2:25)

We now have an expression for the radiative forcing, which gives the change in flux due to the injection of a GHG. If the GHG concentration is allowed to stabilize, a new thermal equilibrium will be established. The temperature will have increased by an amount DT giving a new temperature of T ¼ T0 + DT. Our new radiation equilibrium equation is now a modified version of Eq. 2.21:

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D. Szpunar

Fs ð 1  AÞ ¼ 4



 f þ Df 1 sðT 0 þ DT Þ4 2

(2:26)

We will now make a simplification of Eq. 2.26 by expanding the (T0 + DT)4 term: ðT 0 þ DT Þ4 ¼ T 0 4 þ 4T 0 3 DT þ 6T 0 2 DT 2 þ 4T 0 DT 3 þ DT 4

(2:27)

The next step is to recognize that, for sufficiently small forcing and therefore small temperature change, the higher order terms of DT are sufficiently small to ignore. We therefore have the approximation: ðT 0 þ DT Þ4  T 0 4 þ 4T 0 3 DT

(2:28)

Equation 2.26 then reduces to: Fs ð1  AÞ ¼ 4

 
f þ Df 1 s T 0 4 þ 4T 0 3 DT 2

(2:29)

Equation 2.29 can be further simplified by using Eq. 2.21 to substitute for Fs ð1AÞ : 4

ð1  f =2ÞsT 0

4

 
f þ Df ¼ 1 s T 0 4 þ 4T 0 3 DT 2

(2:30)

Equation 2.30 is then solved for the change in temperature, DT: DT ¼

T 0 Df 8ð1  f =2  Df =2Þ

(2:31)

We will make one final approximation here, and that is because the radiative forcing is so small, the increase in absorption (Df) is small enough compared to the actual absorption that it makes very little difference when added to f/2, and therefore, it is dropped from the denominator, giving: DT ¼

T 0 Df 8ð1  f =2Þ

(2:32)

Equation 2.32 gives the change in temperature expected when mass Dm of species X is added to the atmosphere resulting in an increase in absorption, Df. Finally, we can determine how temperature change and radiative forcing relate through the substitution of Eq. 2.25 into Eq. 2.32:

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Radiative Forcing and the Greenhouse Gases

Df sT 0 4 ; 2

21

2DF sT 0 4   T0 2DF DT ¼ 8ð1  f =2Þ sT 0 4 1 ¼ DF 4ð1  f =2ÞsT 0 3 ¼ lDF

DF ¼

Df ¼

(2:33)

where l is the climate sensitivity parameter. The concept of climate sensitivity is still one of considerable research (Andronova et al. 2007); its importance being that it links radiative forcing to the change in temperature at the Earth’s surface. It can be thought of as “the ability to amplify or reduce the initial temperature change initiated by the external forcing” (Andronova et al. 2007). Note here that this relationship is linear. The climate sensitivity parameter is historically linked to the change in temperature through DT2x, which is the change in temperature resulting from doubling CO2 concentrations. It will not be shown here, but for CO2, the RF is the same for any doubling of CO2 concentration, regardless of the initial concentration. Because of this as well as historical considerations, climate sensitivity is used interchangeably with DT2x.

References American Chemical Society (2009) Chemistry in context: applying chemistry to society, 6th edn. McGraw-Hill Higher Education, New York Andronova N, Schlesinger ME, Dessai S, Hulme M, Li B (2007) The concept of climate sensitivity: history and development. In: Schlesinger ME, Kheshgi HS, Smith J, de la Chesnaye FC, Reilly JM, Wilson T, Kolstad C (eds) Human-induced climate change. Cambridge University Press, Cambridge, UK Archer D, Rahmstorf S (2010) The climate crisis. Cambridge University Press, Cambridge, UK Jacob DJ (1999) Introduction to atmospheric chemistry. Princeton University Press, Princeton

3

Reflective Aerosols and the Greenhouse Effect Kathryn E. Kautzman

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aerosol Origin, Classification, and Formation Mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radiation Interacting with Particles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Quantification of Optical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aerosol Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aerosol Radiative Forcings Versus Radiative Forcings from GHGs . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

23 24 26 26 27 28 29 30

Abstract

The contributions of atmospheric aerosols to add to either a climate-warming effect or climate-cooling effect depend on the chemical composition of the aerosol and the local environment. The best estimation is that the global net effect of aerosols is cooling. The magnitude of this cooling effect is comparable to the warming caused by greenhouse gases, but the uncertainty associated with the total cooling effect is relatively large. An introduction to the properties of aerosols and the role aerosols play in altering the Earth’s radiative budget through direct effects is addressed. Keywords

Aerosols • Radiative forcing • Scattering • Absorption • Refractive index • Single-scattering albedo

K.E. Kautzman Department of Chemistry, Towson University, Towson, MD, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_72, # Springer Science+Business Media Dordrecht 2014

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K.E. Kautzman

Definition Aerosols are liquid or solid particles suspended within the atmosphere. Aerosol particles originate from a variety of sources and perturb the Earth’s energy budget in ways that are dependent upon the particle’s size, shape, composition, location, and lifetime through the scattering and absorption of radiation, termed direct effects, and by acting as cloud condensation nuclei, termed indirect effects. The latest report from the Intergovernmental Panel on Climate Change (IPCC) demonstrates that the largest uncertainty in estimating the radiative budget of the atmosphere is in the poorly constrained effects of aerosol species and how their chemical and physical properties alter the Earth’s energy balance (IPCC 2007). Solar radiation entering the top of the atmosphere provides an input of energy. Some of this energy is absorbed by the atmosphere and by the Earth’s surface, and some is reflected or emitted back out to space. In order for the environment to reach equilibrium, the input and output of energy must balance. The difference of the input of solar radiation minus the output of radiation is called a radiative forcing. Thus radiative forcing is a measure of the energy that is retained by the Earth and is typically given in units of power per area or W/m2. At the top of the atmosphere, a negative effect indicates a loss of energy, or cooling of the atmosphere; a positive radiative forcing indicates a net gain of energy, or a warming effect.

Aerosol Origin, Classification, and Formation Mechanisms The interaction between aerosols and solar radiation is strongly dependent upon the size, shape, and chemical composition of the aerosol. These properties are largely determined by the manner in which the aerosol is generated and upon how the aerosol transforms within the atmosphere. General pathways for the generation, transformation, and removal of aerosols are described in Fig. 3.1. Understanding the size distribution of particles from different formation pathways is important as, according to the Mie Theory, particles interact most strongly with wavelengths of light that are similar in size to the particle diameter. Thus smaller particles interact more strongly with short wavelength radiation (0.1–5 mm) and coarse particles interact with longwave radiation (5–100 mm). Coarse aerosols fall in the 2–50 mm size range and are typically generated by mechanical forces or combustion. For example, mechanical action from the wind on the Earth and ocean surfaces acts to inject mineral dust, vegetation debris, pollen, and sea salt into the atmosphere. Coarse particles are also formed through erupting volcanoes, forest fires, and coal combustion, which spew ash into the atmosphere. Because most coarse particles enter the atmosphere in particulate form, they are referred to as primary aerosols. Coarse particles are sufficiently large that they are removed from the atmosphere by gravitational settling or dry deposition on relatively short time scales of minutes to days.

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Reflective Aerosols and the Greenhouse Effect

25

Fig. 3.1 Formation and removal processes for aerosols. Adapted from (Mahowald et al. 2011)

Smaller particles are classified as either ultrafine (0.001–0.1 mm) or fine aerosol (0.1–2 mm). Typically ultrafine and fine particles are not directly emitted into the atmosphere as particles but are formed by the atmospheric processing of gas-phase species. New ultrafine particles form from the clustering of gases (nucleation). These ultrafine particles rapidly grow by two primary mechanisms: coagulation occurs when small clusters combine to form larger particles or the new particles act as a sink for low-vapor-pressure gas species that can condense on the smaller particles (Jacob 1999). Dependent on the relative humidity, fine and ultrafine particles can also uptake water, altering both their size and shape and thus their optical properties. Furthermore, water uptake provides a medium for chemical reactions both within the aerosol and at the surface, thus altering the chemical and optical properties further. Because the species responsible for forming the aerosols are originally emitted in the gas phase, they are termed secondary aerosols. Particles in the fine size range remain in the atmosphere for days to weeks and are removed by wet and dry deposition (Fig. 3.1).

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K.E. Kautzman

Fig 3.2 Mechanisms of radiation interactions with particles: (a) diffraction, (b) refraction and internal reflection, (c) refraction, (d) absorption, (e) reflection, and (f) emission

Radiation Interacting with Particles A beam of light incident upon a particle can be either scattered or absorbed, thus removing a quantity of the beam of light or altering the light path. Scattering events may occur as reflection, refraction, or diffraction as shown in Fig. 3.2. Absorption, mechanism D in Fig. 3.2, also attenuates light; however, here the energy is transferred to the particle and the energy of the particle increases. The excited particle emits energy to the surrounding atmosphere either in the form of heat or by fluorescence (pathway F). Particles which primarily absorb light create a positive radiative forcing (warming), while scattering events create a negative radiative forcing (cooling). The absorption and scattering interactions of light with particles are dependent on the wavelength of the incident light and the size of the particle.

Quantification of Optical Properties The radiative properties of aerosols can be quantitatively described by a variety of optical terms. Important quantifications of the radiative effects of aerosols include the aerosol’s optical depth, shape factor, and phase function (Bohren and Huffman 1998). Here the interaction of solar radiation and infrared radiation from the Earth with aerosol particles is quantified in terms of the complex refractive index (RI) and the single-scattering albedo. The RI, n, is expressed as n ¼ m + ik, where m depicts the scattering properties of the aerosol and k is the absorption term. Both m and k are dependent on the wavelength of incident radiation. Table 3.1 lists the RI for common atmospheric species at a wavelength of 550 nm. Note that the RI of most species has no intensity in the absorption term; thus they are entirely scattering or cooling. There are a few exceptions; soot and mineral dust both have absorption components. Refractive indices suggested by Seinfeld and Pandis (2006), Ebert et al. (2002), Bond et al. (2006), and Meland et al. (2011).

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Reflective Aerosols and the Greenhouse Effect

Table 3.1 Complex refractive index for atmospheric constituents at 550 nm m ¼ n + ik

Water (liquid) Water (ice) (NH4)2SO4 SiO2 Sea Salt NaCl Soot Mineral Dust

27 n 1.333 1.309 1.53 1.55 1.53 1.544 1.95 2.2 3.26

k 0 0 0 0 0 0 0.79 0.003 0.21

The total radiative properties of aerosols can be described by the combination of scattering and absorption interactions. The sum of the particle interaction with light from scattering and absorption is termed the extinction. Since most aerosol particles are primarily scattering, their optical properties can be defined by the singlescattering albedo (SSA), which is the ratio of how much light a particle scatters to the total extinction. A SSA of 1 represents a particle that is completely scattering, and a SSA of 0 is completely absorbing. Since most atmospheric species primarily scatter light and have a SSA 1, a SSA of less than 0.85 is considered a strong absorber under atmospheric conditions.

Aerosol Types Chemical composition is a key factor in determining the radiative forcing (RF) of aerosols. Chemical composition of aerosols is highly variable and is dependent on the mechanism of aerosol generation as well as upon secondary reactions that the aerosol undergoes within the environment. This complexity is one reason it is difficult to determine an exact magnitude for the radiative forcing by aerosols. Here some sources of aerosols and their contributions to radiative forcing are described. Sulfates: Sulfur is mostly emitted in the form of SO2 from combustion and the burning of fossil fuels. Natural sources of sulfur include dimethylsulfide (DMS) from oceans and to a smaller extent gas and ash emissions from volcanoes. Once emitted, SO2 is oxidized by the atmosphere to form condensed sulfuric acid (H2SO4) particles, which subsequently react with organics and ammonium in the atmosphere. Sulfur-containing particles are typically hygroscopic and play a large role in both the radiative direct and indirect effects. Current assessments suggest a total RF from sulfate species is –0.4 to –1.3 W/m2 (Mahowald et al. 2011; Satheesh and Moorthy 2005). Mineral Dust: Mineral dust originates from wind acting on the surface of deserts to entrain crustal material and minerals into the atmosphere; thus the

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K.E. Kautzman

majority of mineral dust is formed in the Sahara desert, China, and the Middle East. Mineral dusts both scatter and absorb radiation. The exact process is a function of wind speed and of the Earth’s surface. In the visible wavelengths, dust particles primarily scatter radiation; at IR wavelengths, dust is an absorber. The combined RF of this class of aerosols is estimated to be 0.5 W/m2 with SSAs of 0.7–0.98 (Durant et al. 2009). Sea Salt: Sea-salt particles are generated by a wind-driven or wave-driven process involving bubble bursting at the ocean surface. The chemical composition of sea salt is primarily NaCl with contributions from Mg and SO4. The RF contributions from sea salt are 0.6 to 4.0 W/m2 (Satheesh and Moorthy 2005). Volcanoes: The primary components of these aerosols are sulfates, nitrates, and hydrochloric acid. SO2 vapors form sulfuric acid, which nucleates to generate small particles. The large increases in reflective sulfate aerosols lead to a negative RF. The eruption of Mt. Pinatubo in 1991 significantly altered the Earth’s climate and radiation fluxes. Average global reductions in the absorption of solar radiation of 5 W/m2 were observed after the eruption (Seinfeld and Pandis 2006).

Aerosol Radiative Forcings Versus Radiative Forcings from GHGs According to the latest IPCC report, the cooling effect attributed to aerosols is approximately 1.3 (2.2 to 0.5) W/m2, which is comparable to the positive forcing of +1.66 W/m2 from increases in CO2. The radiative forcing (RF) contributions from greenhouse gases (GHGs) are well-defined because concentrations are comparable across the globe, sources and sinks are understood, and the models are mathematically tractable. However, significant uncertainties regarding the magnitude of the effects due to aerosols persist. Contrasts in lifetimes and differences in descriptive pathways for how gases and particles interact with radiation lead to significant dissimilarities in the forcings of GHGs and aerosols. The major differences are summarized in Table 3.2. GHGs generally interact only on the outgoing infrared (IR) radiation from the Earth to create a warming effect (positive forcing). In contrast, aerosols can both scatter and absorb radiation and thus have both a cooling and warming effect on the atmosphere. Furthermore, because aerosols range in size and chemical composition, aerosols interact with radiation over a broader range of the electromagnetic spectrum. Since the GHG effect is a result of gas interaction with longwave radiation emitted from the Earth’s surface, GHG effects occur during both day and night. This is in contrast to direct aerosol effects, which pertain to an alteration in solar flux and are only relevant during daytime. The removal of aerosol species through processes of dry and wet deposition (Fig. 3.1) leads to a comparatively short aerosol lifetime. Once injected/formed in the atmosphere, a particle’s lifetime (within the troposphere) is a few days to a few weeks. Thus the cooling (or warming) caused by the aerosol occurs on an immediate time scale. The warming potential for GHGs is significantly longer

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Reflective Aerosols and the Greenhouse Effect

29

Table 3.2 Comparision of GHG and aerosol forcings Quantification of Optical Properties Spectral Dependence

GHG Absorption of IR is well-quantified

Longwave interactions (infrared) Global Variation Uniform, well mixed Nature of Forcing Forcing occurs during night and day Time scale of Forcing Decades to centuries

Aerosols Quantity is ill-constrained due to complicated dependence on mixing state, structure, composition and size Tropospheric interactions relevant across solar spectrum Strong spatial and temporal variation, locally dependent Forcing only occurs during daylight hours

Days to weeks

and is not fully realized until equilibrium within the atmosphere is achieved. For short-lived greenhouse gases, such as O3 and HCFCs, the equilibrium time scale is on the order of decades. For longer-lived species, such as CO2, CH4, and N2O, equilibrium time scales are on the order of centuries. This provides a predicament; the negative impacts of aerosols relating to visibility and health lead to a desire to decrease aerosol concentrations, but the overall cooling effect aids in masking the “true” magnitude of the GHG effect. If one could simultaneously “turn off” all of the sources of both GHGs and aerosols, the cooling observed from aerosols would disappear in weeks due to short aerosol lifetimes, but the warming trend from GHGs would continue to increase as the current levels of GHGs come to equilibrium in the atmosphere. For example, after the events of September 11, 2001, planes were grounded for 3 days. The reduction in aerosols and aerosol contributions to cloud formation lead to a 1.1  C increase in ground temperatures across the USA (Travis et al. 2002). This demonstrates the potential magnitude and approximate time scale for the aerosol cooling effect at the Earth’s surface.

References Bohren CF, Huffman DR (1998) Absorption and scattering of light by small particles. WileyInterscience, New York Bond TC, Bond TC, Bergstrom RW (2006) Light absorption by carbonaceous particles: an investigative review. Aerosol Sci Tech 40(1):27–67 Durant AJ, Harrison SP, Watson IM, Balkanski Y (2009) Sensitivity to direct radiative forcing by mineral dust to particle characteristics. Prog Phys Geog 33(1):80–102 Ebert M, Weinbruch S, Rausch A, Gorzawski,G, Hoffmann P, Wex H, Helas G (2002) Complex refractive index of aerosols during LACE 98 as derived from the analysis of individual particles. J Geophys Res 170(D21). doi:10.1029/2000JD000195 Intergovernmental Panel on Climate Change (2007) Climate change 2007: the physical science basis. Cambridge University Press, Cambridge, UK

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Jacob DJ (1999) Introduction to atmospheric chemistry. Princeton University Press, Princeton Mahowald N, Ward DS, Kloster S, Flanner MJ, Heald CL, Heavens NG, Hess PG, Lamarque JF, Chuang PY (2011) Aerosol impacts on climate and biogeochemistry. Ann Rev Environ Resour 36:45–74 Meland B, Kleiner PD, Grassian VH, Young MA (2011) Visible light scattering study at 470, 550, and 660 nm of components of mineral dust aerosol: hematite and goethite. J Quant Spectrosc Radiat Transf 112:1108–1118 Satheesh SK, Moorthy KK (2005) Radiative effects of natural aerosols: a review. Atmos Environ 39(11):2089–2110 Seinfeld J, Pandis S (2006) Atmospheric chemistry and physics: from air pollution to climate change. Wiley, Hoboken N J Travis D, Carleton AM, Lauritsen RG (2002) Climatology: contrails reduce daily temperature range- a brief interval when the skies were clear of jets unmasked an effect on climate. Nature 418:601

Additional Recommended Reading Po´sfai M, Buseck P (2010) Nature and climate effects of individual tropospheric particles. Ann Rev Earth Planet Sci 38:17–43 Stier P, Seinfeld JH, Kinne S, Boucher O (2007) Aerosol absorption and radiative forcing. Atmos Chem Phys 7(19):5237–5261

4

Water Cycles and Climate Change Kevin E. Trenberth

Contents Introduction to the Water Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Role of Water in the Climate System and Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Other Changes in Precipitation with Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cross-References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

The hydrological cycle is described. Because the climate is changing from human activities, and there is a direct effect on the hydrological cycle, water resources will also change. The effects of climate change on precipitation, evaporation, and extremes of floods and droughts are elucidated. Keywords

Precipitation • Floods • Droughts • Water vapor • Climate change • Rainfall • Hydrological cycle

Introduction to the Water Cycle Precipitation is the general term for rainfall, snowfall, and other forms of frozen or liquid water falling from clouds. Precipitation is intermittent, and the character of the precipitation when it occurs depends greatly on temperature and the weather situation. The latter determines the storms and supply of moisture through winds

K.E. Trenberth National Center for Atmospheric Research, Boulder, CO, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_30, # Springer Science+Business Media Dordrecht 2014

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and surface evaporation, and how it is gathered together to form clouds. Precipitation forms as water vapor is condensed, usually in rising air that expands and hence cools. The upward motion comes from air rising over mountains, warm air riding over cooler air (warm front), colder air pushing under warmer air (cold front), convection from local heating of the surface, and other weather and cloud systems. Precipitation is therefore also dependent on the presence of storms of one sort or another. The water cycle varies on all time scales. Partly, this arises from the inherently intermittent nature of precipitation. Of particular concern for society and the environment are the damaging heavy rains or prolonged dry spells. Hydrological extreme events are typically defined as floods and droughts. Floods are associated with extremes in rainfall (from tropical storms, thunderstorms, orographic rainfall, widespread extratropical cyclones, etc.), while drought is associated with a lack of precipitation and often extreme high temperatures that contribute to drying. Floods are often fairly local and develop on short time scales, while droughts are extensive and develop over months or years. Both can be mitigated: floods by good drainage systems and drought by irrigation, for instance. Precipitation varies from year to year and over decades, and changes in amount, intensity, frequency, and type (e.g., snow vs. rain) affect the environment and society. Steady moderate rains soak into the soil and benefit plants, while the same rainfall amounts in a short period of time may cause local flooding and runoff, leaving soils much drier at the end of the day. Snow may remain on the ground for some months before it melts and there is runoff. These examples highlight the fact that the characteristics of precipitation are just as vital as the amount in terms of the effect on the soil moisture and stream flow. As air warms to be above the freezing point, precipitation turns to rain. However, the water holding capacity of air increases 6–7 % for every 1  C increase in temperature. This comes from a well-established physical law (the ClausiusClapeyron equation). Hence, increasing atmospheric moisture occurs with a constant relative humidity because of an increase in temperature. In winter, as temperatures drop below freezing point, the air becomes “freeze-dried,” and at very low temperatures, below 10  C, snow tends to become very light with small flakes or even “diamond dust” like. It is only when temperatures are near freezing that huge amounts of snow fall, flakes can be large, and snow can bind together so that one can make snowmen. Similarly, as air rises into regions of lower pressure, it expands and cools, causing water vapor to condense and precipitation to form. Consequently, changes in temperature provide a very fundamental constraint on precipitation amount and type through the water vapor content of the air. Surface moisture effectively acts as an “air-conditioner,” as heat used for evaporation acts to moisten the air rather than warm it. An observed consequence of this partitioning is that summers, in particular, generally tend to be either warm and dry or cool and wet. The long-term mean global hydrological cycle is depicted in Fig. 4.1 based on Trenberth et al. (2007a) who review the past estimates and provide discussion of the sources of data of the storage and flows of water through the Earth system. Several

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Fig. 4.1 The hydrological cycle. Estimates of the main water reservoirs, given in plain font in thousand (103) km3, and the flow of moisture through the system, given in slant font in thousand (103) km3/yr, equivalent to Exagrams (1018 g) per year. Units: thousand cubic km for storage and thousand cubic km/yr for exchanges. From Trenberth et al. (2007a)

aspects remain quite uncertain, and some vary substantially from year to year and as the climate changes. Comprehensive listings of many tables of relevant data are given by Gleick (1993), who notes that “good water data are hard to come by” and that the data are “collected by individuals with differing skills, goals, and intents.”

The Role of Water in the Climate System and Climate Change The Earth’s water cycle is not only of vital interest because of the continual freshwater supply on land for humanity to exploit but also because it plays a central role in the Earth’s energy cycle and climate change. The sun’s radiation enters the atmosphere, and about 30 % is reflected either from clouds or aerosol (particulates) in the atmosphere or from the surface (see Trenberth et al. 2009). Some 47–48 % of the incoming radiation at the top of atmosphere is absorbed at the surface and has to be balanced by cooling to maintain an equilibrium climate. It is estimated that 39 % of the loss comes from net longwave radiative losses, although this involves a very large amount emitted from the surface that is compensated by downwelling radiation from greenhouse gases and clouds within the atmosphere. About 10 % is lost from the surface as sensible heating of the atmosphere, for instance, through thermals. The rest – about 50 % is lost through evaporative

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cooling of the surface: moisture enters the atmosphere as water vapor to subsequently heat the atmosphere when condensed to form precipitation. Because the climate is not in equilibrium, there is a small residual of 0.6 % for the post-2000 period that is absorbed and serves to heat the oceans, melt ice, and cause climate change from the increasing greenhouse gases in the atmosphere owing to human activities. So the Earth is not currently in energy balance, and it follows that the water cycle must also be changing as a consequence. The term “global warming” is often used to refer to the warming of the planet from human influences, and while there are many influences, the biggest comes from interference with the natural flows of energy through the climate system by changing the composition of the atmosphere and especially the greenhouse effect. Changes in aerosol cause regional variations of mixed character. Increases in certain aerosols such as sulfate particles from burning coal result in a milky whitish haze that reflects the sun and causes cooling, while carbonaceous aerosols are more likely to be absorbing and may cause local heating but at the expense of surface heating, and so both kinds can short circuit the hydrological cycle. The largest decrease recorded in global land precipitation followed in the year after the Mount Pinatubo volcanic eruption, owing to cooling from the aerosol deposited in the stratosphere (Trenberth and Dai 2007). While one consequence of global warming is an increase in temperature, and thus the water holding capacity of the atmosphere, another consequence is an increase in evaporation over the oceans or evapotranspiration on land. Accordingly, the water cycle speeds up. For precipitation, climate models typically predict an increase in amount globally of about 2 % per 1  C warming in global mean temperature although this value is quite uncertain. Regionally, this may be small or nonexistent owing to aerosol effects, and the best estimates of global precipitation find no trends of significance (Trenberth 2011). A robust finding in all climate models with global warming is for an increase in evapotranspiration if water is present. In the absence of precipitation, this leads to increased risk of drought, as surface drying is enhanced. It also leads to increased risk of heat waves and wildfires in association with such droughts; because once the soil moisture is depleted, all heating goes toward raising temperatures and wilting plants. However, this is not a simple process as there are multiple downstream effects. The change in atmospheric storage is small compared with the amount cycled through the atmosphere, and thus, any increase in evapotranspiration (E) is largely matched by an increase in precipitation (P) on a global basis. This also means an increase in latent heating of the atmosphere, and that deposition of heat means the vertical temperature structure of the atmosphere is affected. The immediate effect is to stabilize the atmosphere until or unless the heat can be removed by radiative processes or transported elsewhere where it may eventually be radiated to space. The mismatch between the rate of increase in water holding capacity of 7 % versus E and P of 2 % per degree Celsius has other major consequences. Precipitation is inherently intermittent and, on average, the frequency of precipitation over the global oceans is 10.9 % (Ellis et al. 2009), varying from values factors of 2–3 times higher at high latitudes to much lower in the subtropical regions. Over land,

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the average values are less and can be almost zero in deserts (see Dai 2001). Accordingly, rates of precipitation, conditional on when it does fall, are much greater than rates of evaporation, which are fairly continuous. Overall, the value is probably a factor of about 10–25, depending on the threshold used for precipitation. It also follows that most precipitation does not come directly from local evaporation, as the mismatch in rates is so great. Nor can it come from the moisture stored in a column, which averages globally about 19 mm (January) to 22 mm (July), and varies with region so that values are over 50 mm in the tropics. Accordingly, most moderate and heavy precipitation comes from convergence of moisture by the winds of the storm that convey the moisture from remote regions into the storm that produces the precipitation (see Trenberth et al. 2003; Trenberth 2011). Globally on average, precipitation comes from regions 3 to 5 times the radius of the rain region – or 10–25 times the areal value. This rule of thumb seems to apply remarkably well to many weather systems, including hurricanes (Trenberth et al. 2007b). Hence, because precipitation comes primarily from moisture convergence, an increase in atmospheric moisture means increased intensity of events: heavier rains and also heavier snows, as is generally observed to be happening (IPCC 2007). The rate of increase of precipitation intensity can even exceed the modest ClausiusClapeyron rate because the additional latent heat released feeds back and invigorates the storm that causes the rain in the first place, further enhancing convergence of moisture. However, the total precipitation amount is constrained by energy availability which therefore increases at a much lower rate, and so the frequency or duration must decrease, making for longer dry spells between events in some way. This too is being observed in places where it has been examined (Groisman and Knight 2008).

Other Changes in Precipitation with Climate Change To a first approximation, the pattern of winds do not change much with climate change, and thus, the increases in water vapor guarantee that wet areas get wetter and dry areas get drier. This is referred to as “the rich get richer and the poor get poorer” change in precipitation. However, as heat is transported upwards during precipitation, with more moisture, there is greater latent heat released and thus less need for the overall circulation to be as vigorous. An implication is that large-scale overturning circulations, such as the Hadley and Walker cells and monsoons, are apt to weaken. A further implication is that there must be a decrease in light and moderate rains and/or a decrease in the frequency of rain events, as found in several studies. Thus, the prospect may be for fewer but more intense rainfall – or snowfall – events. Other changes occur as the patterns of where storms form and tracks change, and thus, the global atmospheric circulation plays a key role in the distribution of precipitation. The distribution and timing of floods and droughts are most profoundly affected by the cycle of El Nin˜o-Southern Oscillation (ENSO) events, particularly in

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the tropics and over much of the midlatitudes of Pacific-rim countries. Accordingly, small changes in sea surface temperature (see chapter ▶ Sea-Surface Temperature) distributions are important in the tropics. The extremes of floods and droughts with ENSO become amplified with global warming. These aspects have enormous implications for agriculture, hydrology, and water resources, yet they have not been adequately appreciated or addressed in many studies of impacts of climate change. In the twenty-first century, a robust pattern of increased precipitation polewards of about 45 is projected due to the increase in water vapor in the atmosphere and the resulting increase in vapor transport from lower latitudes. This is accompanied by decreased subtropical precipitation, although less so over Asia. Extratropical storm tracks are projected to move poleward, with consequent changes in wind, precipitation, and temperature patterns, continuing the broad pattern of observed trends over the last half century. Along with a poleward expansion of the subtropical high-pressure systems, this leads to a drying tendency in the subtropics that is especially pronounced at the higher-latitude margins of the subtropics. The IPCC (2007) also concludes that future tropical cyclones (typhoons and hurricanes) will likely become more intense, with larger peak wind speeds and more heavy precipitation associated with ongoing increases of tropical SSTs. Because an intense tropical cyclone takes heat out of the ocean and mixes the ocean, leaving behind a much stronger cold wake than a more modest storm, there may be fewer tropical cyclones as a whole. Possible increases in stability in the atmosphere also lead to fewer tropical cyclones. Nonetheless, increased risk of flooding is a likely outcome from land-falling tropical storms. As temperatures rise, the likelihood of precipitation falling as rain rather than snow increases, especially in autumn and spring at the beginning and end of the snow season, and in areas where temperatures are near freezing. Such changes are already observed in many places, especially over land in middle and high latitudes of the Northern Hemisphere, leading to increased rains but reduced snowpacks, and consequently diminished water resources in summer, when they are most needed. In extratropical mountain areas, the winter snowpack forms a vital resource, not only for skiers but also as a freshwater resource in the spring and summer as the snow melts. Yet warming makes for a shorter snow season with more precipitation falling as rain rather than snow, earlier snowmelt of the snow that does exist, and greater evaporation and ablation. These factors all contribute to diminished snowpack. It is evident that climate change has large direct impacts on the hydrological cycle and, in particular, its extremes, making managing and using water resources more challenging. Dealing with drought 1 year, and then floods the next, makes for major challenges for water managers on how to save in times of excess for those times when there is too little. Acknowledgments The National Center for Atmospheric Research is sponsored by the National Science Foundation. This work is supported by NASA grant NNX11AG69G.

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Cross-References ▶ Sea-Surface Temperature

References Dai A (2001) Global precipitation and thunderstorm frequencies. Part I: Seasonal and interannual variations. J Climate 14:1092–1111 Ellis TD, L’Ecuyer T, Haynes JM, Stephens GL (2009) How often does it rain over the global oceans? The perspective from CloudSat. Geophys Res Lett 36, L03815. doi:10.1029/ 2008GL036728 Gleick PH (1993) Water in crisis: a guide to the world’s fresh water resources. Oxford University Press, New York, 504 pp Groisman PY, Knight RW (2008) Prolonged dry episodes over the conterminous United States: new tendencies emerging during the last 40 years. J Climate 21:1850–1862 IPCC (Intergovernmental Panel on Climate Change) (2007) In: Solomon S, Qin D, Manning M, Chen Z, Marquis MC, Averyt KB, Tignor M, Miller HL (eds) Climate change 2007. The physical science basis. Cambridge University Press, Cambridge, UK/New York Trenberth KE (2011) Changes in precipitation with climate change. Climate Res 47:123–138. doi:10.3354/cr00953 Trenberth KE, Dai A (2007) Effects of Mount Pinatubo volcanic eruption on the hydrological cycle as an analog of geoengineering. Geophys Res Lett 34, L15702. doi:10.1029/ 2007GL030524 Trenberth KE, Dai A, Rasmussen RM, Parsons DB (2003) The changing character of precipitation. Bull Am Meteorol Soc 84:1205–1217 Trenberth KE, Smith L, Qian T, Dai A, Fasullo J (2007a) Estimates of the global water budget and its annual cycle using observational and model data. J Hydrometeorol 8:758–769 Trenberth KE, Davis CA, Fasullo J (2007b) Water and energy budgets of hurricanes: case studies of Ivan and Katrina. J Geophys Res 112, D23106. doi:10.1029/2006JD008303 Trenberth KE, Fasullo JT, Kiehl J (2009) Earth’s global energy budget. Bull Am Meteorol Soc 90:311–323

5

Global Dimming and Brightening Martin Wild

Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Observational Evidence and Possible Causes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Environmental Implications of Dimming and Brightening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

40 40 44 46

Abstract

A fundamental determinant of climate and life on our planet is the solar radiation (sunlight) incident at the Earth’s surface. Any change in this precious energy source affects our habitats profoundly. Until recently, for simplicity and lack of better knowledge, the amount of solar radiation received at the Earth surface was assumed to be stable over the years. However, there is increasing observational evidence that this quantity undergoes significant multi-decadal variations, which need to taken into account in discussions of climate change and solar energy generation. Coherent periods and regions with prevailing declines (“dimming”) and inclines (“brightening”) in surface solar radiation have been detected in the worldwide observational networks, often in accord with anthropogenic air pollution patterns. This paper highlights the main characteristics of this phenomenon, and provides a conceptual framework for its causes as well as an overview over potential environmental implications. Keywords

Solar energy • Global dimming and brightening • Earth radiation budget • Decadal climate variations • Air pollution and climate

M. Wild Eidgeno¨ssiche Technische Hochschule (ETH) Zurich, Institute for Atmospheric and Climate Science, Zurich, Switzerland e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_27, # Springer Science+Business Media Dordrecht 2014

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Introduction The major anthropogenic impact on climate and environments occurs through a modification of the Earth’s radiation balance by changing the amount of greenhouse gases and aerosol in the atmosphere. The amount of solar radiation reaching the Earth’s surface is thereby particularly important as it provides the primary source of energy for life on the planet and states a major component of the surface energy balance which governs the thermal and hydrological conditions at the Earth’s surface. On a more applied level, knowledge on changes in this quantity is also crucial for the planning and management of the rapidly growing number of solar power plants in support of the world’s pressing demands on nuclear- and carbon-free energy sources. Any change in this precious energy source could therefore affect our life and environments profoundly (Wild 2012). Observational and modeling studies emerging in the past two decades indeed suggest that surface solar radiation (SSR) is not necessarily constant on decadal timescales as often assumed for simplicity and lack of better knowledge, but shows substantial decadal variations. Largely unnoticed over a decade or more, this evidence recently gained a rapid growth of attention under the popular expressions “global dimming” and “brightening”, which refer to a decadal decrease and increase in SSR, respectively.

Observational Evidence and Possible Causes Monitoring of SSR began in the early twentieth century at selected locations and since the mid-century on a more widespread basis. Many of these historic radiation measurements have been collected in the Global Energy Balance Archive (GEBA, Gilgen et al. 1998) at ETH Zurich and in the World Radiation Data Centre (WRDC) of the Main Geophysical Observatory, St. Petersburg. In addition, more recently, highquality surface radiation measurements, such as those from the Baseline Surface Radiation Network (BSRN, Ohmura et al. 1998) and from the Atmospheric Radiation Measurement Program (ARM), have become available. These networks measure surface radiative fluxes at the highest possible accuracy with well-defined and calibrated state-of-the-art instrumentation at selected worldwide distributed sites. Changes in SSR from the beginning of widespread measurements in the 1950s up to the 1980s have been analyzed in numerous studies (e.g., Ohmura and Lang 1989; Gilgen et al. 1998; Stanhill and Cohen 2001 and references therein; Liepert 2002; Wild 2009 and references therein). These studies report a general decrease of SSR at widespread locations over land surfaces between the 1950s and 1980s. This phenomenon is now popularly known as “global dimming” (see Fig. 5.1 upper panel, for a schematic illustration). Increasing air pollution and associated increase in aerosol concentrations are considered a major cause of the observed decline of SSR (e.g., Stanhill and Cohen 2001;

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Fig. 5.1 Schematic representation of “dimming” and “brightening” periods over land surfaces. During “dimming” (1950s–1980s, upper panel), the decline in surface solar radiation (SSR) may have outweighed increasing atmospheric downwelling thermal radiation (LW↓) from enhanced greenhouse gases and effectively counteracted global warming, causing only little increase in surface thermal emission (LW↑). The resulting reduction in radiative energy at the Earth’s surface may have attenuated evaporation and its energy equivalent, the latent heat flux (LH), leading to a slowdown of the water cycle. With the transition from “dimming” to “brightening” (1980s–2000s, lower panel), the enhanced greenhouse effect has no longer been masked, causing more rapid warming, stronger evaporation/LH, and an intensification of the water cycle. Values denote best estimates of overall changes in surface energy fluxes over both periods in Wm 2 (ranges of literature estimates for SSR dimming/brightening in parentheses). Positive/red (negative/blue) numbers denote increasing (decreasing) magnitudes of the energy fluxes in the direction indicated by the arrows (From Wild (2012))

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Wild 2009). Changes in cloud amount and optical properties, which may or may not have been linked to the aerosol changes, have also been proposed to contribute to the dimming (e.g., Liepert 2002). An attempt has been made in Norris and Wild (2007) to differentiate between aerosol and cloud impacts on radiative changes over Europe. They show that changes in cloud amount cannot explain the changes in SSR, pointing to aerosol direct and indirect effects as major cause of these variations. Alpert et al. (2005) found that the decline in SSR in the 1950s to 1980s period is particularly large in areas with dense population, which also suggests a significant anthropogenic influence through air pollution and aerosols. Several studies (e.g., Dutton et al. 2006; Wild et al. 2009 and references therein) noted a dimming over the 1950s–1980s period also at remote sites, suggesting that the phenomenon is not of purely local nature and air pollution may have far-reaching effects (a concept on how SSR in remote areas may be modulated by subtle changes in background aerosol levels is introduced below). More recent studies using SSR records updated to the year 2000 found, however, a trend reversal and partial recovery at many of the sites since the 1980s. The term “brightening” was thereby coined to emphasize that the decline in SSR and associated global dimming no longer continued after the 1980s (Wild et al. 2005) (Fig. 5.1, lower panel). Particularly in industrialized areas, the majority of the sites showed some recovery from prior dimming, or at least a levelling off, between the 1980s and 2000. The brightening has been somewhat less coherent than the preceding dimming, with trend reversals at widespread locations, but still some regions with continued decrease, such as in India (see Wild 2009, 2012 for an overview). Brightening is not just found under all sky conditions, but often also under clear skies, pointing once more to aerosols as major causes of this trend reversal (e.g., Wild et al. 2005; Norris and Wild 2007). The transition from decreasing to increasing SSR is in line with a similar shift in atmospheric clear sky transmission determined from pyrheliometer measurements at a number of sites (Fig. 5.2). This transition is also in line with changes in aerosol and aerosol precursor emissions derived from historic emission inventories, which also show a distinct trend reversal during the 1980s, particularly in the industrialized regions (e.g., Streets et al. 2006; Stern 2006). The trend reversal in aerosol emission towards a reduction and the associated increasing atmospheric transmission since the mid-1980s may be related to air pollution regulations and the breakdown of the economy in Eastern European countries. A reduction of aerosol optical depth over the world oceans since 1990, which may be indicative of the global background aerosol level, was inferred from satellite data by Mishchenko et al. (2007). This fits well to the general picture of a widespread transition from dimming to brightening seen in the surface radiation observations at the same time. Updates on the SSR evolution beyond the year 2000 show mixed tendencies. Overall, observed brightening is less distinct after 2000 compared to the 1990s at many sites. Brightening continues beyond 2000 at sites in Europe and the USA, but levels off at Japanese sites, and shows some indications for a renewed dimming in China after a phase of stabilization during the 1990s, while dimming persists throughout in India (Wild et al. 2009). On the other hand, the longest observational

Global Dimming and Brightening

Fig. 5.2 Time series of annual mean atmospheric transmission under cloud-free conditions determined from pyrheliometer measurements at various sites in Russia (Moscow), Estonia (TartuToravere and Tiirikoja), Switzerland (Payerne), and Japan (average of 14 sites) (From Wild et al. (2005), online supporting material)

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records, which go back to the 1920s and 1930s at a few sites in Europe, further indicate some brightening tendencies during the first half of the twentieth century, known as “early brightening” (Ohmura 2009; Wild 2009). Wild (2009, 2012) proposed a conceptual framework for the explanation of dimming and brightening, suggesting that aerosol-induced dimming and brightening can be amplified or dampened by aerosol-cloud interactions depending on the prevailing pollution levels. In pristine regions, small changes in cloud condensation nuclei (CCN) can have a much bigger impact on cloud characteristics than in polluted environments, because clouds show a nonlinear (logarithmic) sensitivity to CCN (e.g., Kaufman et al. 2005). Additional CCN due to air pollution in pristine regions may therefore be particularly effective in increasing the formation, lifetime, and albedo of clouds (Kaufman et al. 2005; Rosenfeld et al. 2006), which all act towards a reduction of SSR through enhanced cloud shading. Thus, aerosol-cloud interactions in pristine environments may cause a strong amplification of dimming (brightening) trends induced by small increases (decreases) in aerosols. This implies that dimming/ brightening could be substantial even in areas far away from pollution sources, where small changes in background aerosol levels induced by long-range transports can effectively alter SSR through cloud modifications. This mechanism potentially could also be responsible for the brightening over oceans with decreasing aerosol background levels (Mishchenko et al. 2007) between the mid-1980s and 2000 consistently seen in the satellite-derived SSR records (Wild 2009 and references therein). In polluted regions, on the other hand, cloud microphysics effects tend to saturate with the logarithmic sensitivity to CCN, whereas the direct extinction of SSR by aerosols becomes more relevant, which increases proportionally to the aerosol

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loadings. Absorbing pollution layers further heat and stabilize the atmosphere and attenuate SSR and related surface evaporation. This generally leads to a suppression of convective cloud formation and dissolves clouds in layers heated by absorbing aerosol (known as semi-direct aerosol effect). The associated reduced cloud shading may partly counteract the aerosol-induced reduction of SSR in heavily polluted areas. Thus, in contrast to pristine areas, aerosol-cloud interactions may tend to dampen dimming/brightening trends induced by direct aerosol effects (Wild 2009, 2012).

Environmental Implications of Dimming and Brightening A growing number of studies provide evidence that the variations in SSR have a considerable impact on climate and environmental change (see Wild (2009, 2012) for a review). Wild et al. (2007) investigated the impact of dimming and brightening on global warming. They present evidence that SSR dimming was effective in masking and suppressing greenhouse warming, but only up to the mid-1980s, when dimming gradually transformed into brightening. Since then, the uncovered greenhouse effect reveals its full dimension, as manifested in a rapid temperature rise (+0.38  C/decade over land since mid-1980s). More recently, Wild (2012) pointed out that the absence of global warming from the 1950s to 1980s and the subsequent reversal into rapid warming was most prominently seen on the Northern Hemisphere, while on the Southern Hemisphere rather a steady gradual warming since the 1950s was observed (Fig. 5.3). This fits well to the asymmetric hemispheric evolution of anthropogenic air pollution which strongly increased from the 1950s to the 1980s and declined thereafter on the Northern Hemisphere, while pollution levels on the Southern Hemisphere were an order of magnitude lower and steadily increased with no trend reversal (Wild 2012; Stern 2006). This again points to a possible large-scale influence of aerosol-induced SSR dimming and brightening on global warming. Interestingly enough, the suppression of warming during the dimming period on the Northern Hemisphere was even slightly stronger over ocean than over land areas (Wild 2013) (slight cooling of 0.03  C per decade over oceans between 1958 and 1985, compared to a slight warming over land with +0.04  C per decade over the same period, based on data from the Climate Research Unit, Norwich, and the Hadley Centre, Exeter). Even though anthropogenic air pollution sources are located over land, subtle changes in background aerosol levels over the relatively pristine oceans could have amplified SSR trends through effective cloudaerosol interactions as outlined in the conceptual framework above. This may explain the lack of warming particularly also over oceans during this period (Wild 2013). SSR is also a major determinant of surface evaporation and thereby the main driver of the global water cycle (Wild and Liepert 2010). Wild et al. (2004) suggested that surface solar energy reductions outweighed the increasing thermal energy from the greenhouse effect from the 1960s to 1980s, resulting in a reduction of surface net radiation and associated evaporation over land surfaces, causing an attenuation of the intensity of the associated water cycle (Figs. 5.1 and 5.4). In contrast, for the more recent period 1980s–2000s, Wild et al. (2008) pointed out that SSR brightening adds to the increasing

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Fig. 5.3 Annual 2-m temperature anomalies observed on the Northern (a) and Southern Hemispheres (b). Observations from HadCRUT3, anomalies with respect to 1960–1990. Linear trends over the dimming phase (1950s–1980s) in blue, over the brightening phase (1980s–2000s) in red. On the polluted Northern Hemisphere, observed warming is much smaller during dimming with strong aerosol increase than during subsequent brightening with aerosol decrease. On the more pristine Southern Hemisphere, with greenhouse gases as sole major anthropogenic forcing, observed warming is similar during both periods (Adapted from Wild (2012))

Precipitation 60

Fig. 5.4 Observational estimates of annual precipitation anomalies from 1950 to 2008 over the Northern Hemisphere land masses. Data from the Global Historic Climate Network. Reference period for anomalies is 1961–1990. Eleven-year running mean in blue. Units mm (From Wild (2012))

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energy from the enhanced greenhouse effect, leading to higher evaporation and an intensification of the global terrestrial water cycle since the 1980s (Figs. 5.1 and 5.4). Impacts of the transition from dimming to brightening can further be seen in the more rapid retreats of glaciers and snow cover, which became evident since the 1980s as soon as the dimming disappeared (Wild 2009 and references therein). Modeling studies further suggest that SSR dimming/brightening may also impact the terrestrial carbon cycle and plant growth (Mercado et al. 2009). During dimming, plant photosynthesis and associated terrestrial carbon uptake might have been enhanced despite a reduction in SSR, since the stronger aerosol and cloud scattering enlarged the diffuse radiative fraction in this period. Diffuse light penetrates deeper into the vegetation canopies than the direct sunbeam and can therefore be more effectively used by plants for photosynthesis. Further research will be required to establish the full dimension of impacts of dimming and brightening on climate and environmental change.

References Alpert P, Kishcha P, Kaufman YJ, Schwarzbard R (2005) Global dimming or local dimming? Effect of urbanization on sunlight availability. Geophys Res Lett 32(17):L17802. doi:10.1029/ 2005gl023320 Dutton EG, Nelson DW, Stone RS, Longenecker D, Carbaugh G, Harris JM, Wendell J (2006) Decadal variations in surface solar irradiance as observed in a globally remote network. J Geophys Res Atmos 111(D19):D19101. doi:10.1029/2005jd006901 Gilgen H, Wild M, Ohmura A (1998) Means and trends of shortwave irradiance at the surface estimated from global energy balance archive data. J Climate 11(8):2042–2061 Kaufman YJ, Koren I, Remer LA, Rosenfeld D, Rudich Y (2005) The effect of smoke, dust, and pollution aerosol on shallow cloud development over the Atlantic Ocean. Proc Natl Acad Sci USA 102(32):11207–11212. doi:10.1073/pnas.0505191102 Liepert BG (2002) Observed reductions of surface solar radiation at sites in the United States and worldwide from 1961 to 1990. Geophys Res Lett 29(10):1421. doi:10.1029/2002gl014910 Mercado LM, Bellouin N, Sitch S, Boucher O, Huntingford C, Wild M, Cox PM (2009) Impact of changes in diffuse radiation on the global land carbon sink. Nature 458(7241):U1014–U1087. doi:10.1038/Nature07949 Mishchenko MI, Geogdzhayev IV, Rossow WB, Cairns B, Carlson BE, Lacis AA, Liu L, Travis LD (2007) Long-term satellite record reveals likely recent aerosol trend. Science 315(5818):1543–1543. doi:10.1126/science.1136709 Norris JR, Wild M (2007) Trends in aerosol radiative effects over Europe inferred from observed cloud cover, solar “dimming” and solar “brightening”. J Geophys Res Atmos 112(D8): D08214. doi:10.1029/2006jd007794 Ohmura A (2009) Observed decadal variations in surface solar radiation and their causes. J Geophys Res Atmos 114:D00d05. doi:10.1029/2008jd011290 Ohmura A, Lang H (1989) Secular variations of global radiation in Europe. Paper presented at the IRS’88: current problems in atmospheric radiation, Lille Ohmura A, Dutton EG, Forgan B, Frohlich C, Gilgen H, Hegner H, Heimo A, Konig-Langlo G, McArthur B, Muller G, Philipona R, Pinker R, Whitlock CH, Dehne K, Wild M (1998) Baseline surface radiation network (BSRN/WCRP): new precision radiometry for climate research. Bull Am Meteorol Soc 79(10):2115–2136

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Rosenfeld D, Kaufman YJ, Koren I (2006) Switching cloud cover and dynamical regimes from open to closed Benard cells in response to the suppression of precipitation by aerosols. Atmos Chem Phys 6:2503–2511 Stanhill G, Cohen S (2001) Global dimming: a review of the evidence for a widespread and significant reduction in global radiation with discussion of its probable causes and possible agricultural consequences. Agr Forest Meteorol 107(4):255–278 Stern DI (2006) Reversal of the trend in global anthropogenic sulfur emissions. Glob Environ Change Human Policy Dimens 16(2):207–220. doi:10.1016/j.gloenvcha.2006.01.001 Streets DG, Wu Y, Chin M (2006) Two-decadal aerosol trends as a likely explanation of the global dimming/brightening transition. Geophys Res Lett 33(15):L15806. doi:10.1029/2006gl026471 Wild M (2009) Global dimming and brightening: a review. J Geophys Res Atmos 114:D00d16. doi:10.1029/2008jd011470 Wild M (2012) Enlightening global dimming and brightening. Bull Am Meteorol Soc 93(1):27–37. doi:10.1175/Bams-D-11-00074.1 Wild M (2013) Relevance of Decadal Variations in Surface Radiative Fluxes for Climate Change. AIP Conf Proc 1531:728–731. doi: 10.1063/1.4804873 Wild M, Liepert B (2010) The earth radiation balance as driver of the global hydrological cycle. Environ Res Lett 5(2), 025003. doi:10.1088/1748-9326/5/2/025003 Wild M, Ohmura A, Gilgen H, Rosenfeld D (2004) On the consistency of trends in radiation and temperature records and implications for the global hydrological cycle. Geophys Res Lett 31(11):L11201. doi:10.1029/2003gl019188 Wild M, Gilgen H, Roesch A, Ohmura A, Long CN, Dutton EG, Forgan B, Kallis A, Russak V, Tsvetkov A (2005) From dimming to brightening: decadal changes in solar radiation at earth’s surface. Science 308(5723):847–850. doi:10.1126/science.1103215 Wild M, Ohmura A, Makowski K (2007) Impact of global dimming and brightening on global warming. Geophys Res Lett 34(4):L04702. doi:10.1029/2006gl028031 Wild M, Grieser J, Schaer C (2008) Combined surface solar brightening and increasing greenhouse effect support recent intensification of the global land-based hydrological cycle. Geophys Res Lett 35(17):L17706. doi:10.1029/2008gl034842 Wild M, Truessel B, Ohmura A, Long CN, Konig-Langlo G, Dutton EG, Tsvetkov A (2009) Global dimming and brightening: an update beyond 2000. J Geophys Res Atmos 114:D00d13. doi:10.1029/2008jd011382

6

Paleoclimates Thomas M. Cronin

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Earth’s Climate History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Application of Paleoclimate Data to Modern Challenges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cross-References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

Evidence for large changes in Earth’s climate is well documented in geological records, and they play an increasingly important role in providing a context for modern and future climate change. Global and regional climate changes occur over all timescales due to many external and internal factors. For example, changes in Earth’s orbital configuration due to gravitational changes in the solar system affect the seasonal and geographic distribution of solar energy. Orbitally forced changes in insolation over 105 to 106 year timescales can be amplified through atmosphere-ocean interactions, influencing the concentration of atmospheric carbon dioxide (CO2) and global radiative greenhouse gas forcing. Internal factors, including dynamical changes in atmosphere-ocean circulation, changes in ice sheet and glacier mass balance, and large hydrological events such as glacial lake drainage, also influence climate. These and other processes can affect global sea level, ocean circulation and heat transport, and regional precipitation. Small changes in total solar irradiance reaching Earth’s atmosphere and volcanic events can also catalyze climate shifts over relatively short timescales.

T.M. Cronin U.S. Geological Survey, Reston, VA, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_45, # Springer Science+Business Media Dordrecht 2014

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Keywords

Paleoclimatology • Ice cores • Carbon dioxide • Ocean circulation • Orbital (Milankovitch) cycles • Abrupt climate transitions • Sea-level change

Definition Paleoclimatology is the study of climate changes preserved in the geological record using natural archives such as glacial ice, air bubbles preserved in ice, tree rings, marine and lake sediments, speleothems (calcite precipitated from groundwater), coral skeletons, paleosols (ancient soils), and mollusk shells. The field encompasses many disciplines including paleoceanography, paleolimnology, glaciology, dendroclimatology, ice core paleoclimatology, geochronology, and paleoclimate modeling (Bradley 1999; Ruddiman 2007; Cronin 2009). Climate proxies are chemical (stable isotopic, trace element, organic geochemical), physical (geomorphological, sedimentological), and biological (species’ ecology, fossil assemblages) indicators of climate parameters such as temperature, glacial ice volume, sea-level positions, land vegetation, polar sea ice cover, and surface and deep ocean circulation that are preserved in paleoclimate archives.

Earth’s Climate History Earth’s climate changes over all timescales due to multiple causes and feedback mechanisms. Over long timescales (106 to 108 years), geological processes influence Earth’s climate by changing atmospheric chemistry (including concentrations of greenhouse gases) and circulation, ocean basin configuration, ocean circulation and heat transport, continental elevations, bedrock weathering, and global and regional hydrology. Some important geological processes are plate tectonics and seafloor spreading, orogeny (mountain building), volcanic activity, continental weathering, land-to-sea sediment and geochemical transport, and global biogeochemical cycling. Over 105- to 106-year timescales, cyclic changes in the seasonal and geographic distribution of solar energy reaching Earth’s atmosphere are caused by gravitational variations in the solar system. These insolation changes, embodied in the orbital theory of climate change (the Milankovitch or astronomical theory), are the main catalyst of glacial-interglacial climatic cycles over the last few million years and are often called the pacemaker of the ice ages (Fig. 6.1). Orbitally forced glacialinterglacial cycles are best known over the last 800,000 years from deep-sea sediments, Antarctic ice cores, lake sediments, windblown loess, and speleothems. During these cycles, Earth’s mean temperature fluctuated about 5  C, global sea level varied up to 130–140 m due to the growth and decay of large continental ice sheets, and atmospheric CO2 and concentrations varied from 180 parts per million volume (ppmv) during glacial periods to 300 ppmv during interglacials. Methane (CH4) also oscillated from 360 to 690 parts per billion (ppbv). The large increase in

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Fig. 6.1 Orbital glacial-interglacial climatic cycles over the last 800,000 years from 3 proxy records. (a) Antarctic ice core record of temperature anomalies with respect to the mean temperature of the last millennium from EPICA Dome C (EDC) ice core based on deuterium isotope data plotted on the EDC3 gas age timescale (Parrenin et al. 2007; Loulergue et al. 2007; Jouzel et al. 2007). Marine Isotope Stages (MIS) are labeled, odd stages are interglacial periods, and even stages are glacial periods. (b) Antarctic ice core records of atmospheric carbon dioxide uthi et al. 2008). EPICA (CO2) concentrations (from Petit et al. 1999; Siegenthaler et al. 2005; L€ Dome C CO2 data (measured at Bern [red and orange], Grenoble [blue], Taylor Dome [green], and Vostok [purple]). CO2 values are on the EDC3 gas age scale. (c) Deep-sea benthic Foraminifera oxygen isotope (d18O) curve called the LR04 stack from Lisiecki and Raymo (2005). Curve is an average of 57 globally distributed benthic d18O records from foraminiferal calcite tests used to measure global ice volume and deep ocean temperature

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atmospheric CO2 concentrations during deglaciation is most likely due to its release from the world’s oceans and its effect was to amplify insolation-driven climate changes. In addition to excellent records of orbital cycles over the last 800,000 years, orbital climate cycles are also known from much older parts of the geological record mainly from cyclic sediment records containing evidence for large changes in ocean temperature, circulation, productivity, and other parameters. Climate also changes abruptly, over millennial and centennial timescales, sometimes when a threshold in the climate system is crossed and new equilibrium climate is achieved. Two types of millennial climate change occurred during the last glacial period about 70,000–25,000 years ago: Dansgaard-Oeschger (D/O) events, first identified first in Greenland ice core stable isotopic measurements, and Heinrich events, discovered in ice-rafted sediment layers in deep-sea cores. D/O events, which are characterized by atmospheric temperature shifts of 10–15  C in the subpolar North Atlantic region, typically begin abruptly, within a few decades, and last between 800 and 2,000 years and therefore are referred to as millennial-scale climate variability. Often associated with large D/O events, Heinrich events represent catastrophic discharges of icebergs from ice sheets surrounding the northern North Atlantic Ocean. Abrupt millennial-scale climate transitions also characterized the last deglacial period from about 20,000 to 11,500 years ago and, with lower amplitude, the Holocene interglacial period (11,500-present). The Younger Dryas cooling event between 13,000 and 11,700 years ago interrupted an otherwise global deglacial warming and represents one of the largest deglacial climate reversals. One hypothesized mechanism causing abrupt climate transitions involves the drainage of massive glacial lake formed from meltwater derived from retreating Laurentide and Fennoscandian Ice Sheets in North American and Eurasia, respectively. According to some climate models, large freshwater discharges might affect large-scale meridional overturning circulation and heat transport of the world’s ocean. Glacial Lake Agassiz, located in former glaciated regions in central Canada, had multiple drainage episodes during its 5,000-year history. The timing and routing of glacial lake discharges through the Hudson, St. Lawrence, and Mackenzie Rivers and through Hudson Strait and their possible impacts on the ocean/climate system are actively researched topics. Earth’s climate also varied during the Holocene epoch (11,700 to present). Holocene climate of the last 2 millennia, a period that included the warm Medieval Climate Anomaly (AD 800–1400) and the Little Ice Age (AD 1400–1900), is intensely studied because it provides the baseline climate variability against which human-induced climate changes can be assessed. Tree ring, speleothem, and coral proxy records provide a history of atmospheric and ocean temperatures, respectively, often at annual resolution. Ice cores from the Greenland and Antarctic Ice Sheets, smaller ice caps, and high-elevation Alpine glaciers provide high- and low-latitude climate records over various timescales, while sediments in high deposition rate areas of the oceans can yield decadal- to centennial-scale ocean history. Proxy reconstructions from these archives extend the relatively limited time period covered by historical record of temperature obtained from instruments and satellites.

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Application of Paleoclimate Data to Modern Challenges The paleoclimate records summarized above are applicable to many pressing issues in the study of present and future climate change. One important example is distinguishing climate change caused by humans (i.e., anthropogenic) from changes caused by natural phenomena, such as solar output, volcanic activity, or oceanatmosphere processes. Proxy and instrumental temperature records combined with reconstructions of past volcanic activity and solar irradiance show that at least half of the global atmospheric warming at the Earth’s surface since the 1950s was caused by anthropogenic greenhouse gases rather than natural variability. Another application of paleoclimate data uses knowledge of past climate changes caused by varying atmospheric CO2 concentrations to improve our understanding of Earth’s climate sensitivity to greenhouse gas forcing. Paleo-CO2 values for the last 800,000 years are measured directly from air bubbles trapped in ice cores. Prior to 800,000 years ago, atmospheric CO2 concentrations are reconstructed from indirect proxy methods, including leaf stomatal density and the geochemistry of algal biomarkers, fossil soils, and shells of small marine protists called Foraminifera. During the Cretaceous (145–65 million years ago) and early Cenozoic (55–35 million years ago), CO2 concentrations sometimes exceeded 1,000 parts ppmv. At these times, polar temperatures were up to 20  C, the tropics were several degrees warmer than today, and global sea level was much higher than today due to minimal polar land ice. During the mid-Pliocene, about 4–3 million years ago, atmospheric CO2 concentrations were roughly 350–420 ppmv and global temperature was several degrees warmer than today. The CO2-climate link is especially important to address issues such as global sea-level rise and ocean acidification because modern glaciers and ice sheets show negative mass balance (net melting) and the global ocean continues to take up anthropogenic CO2. In this sense, paleo-records of high-CO2 climates can help assess what might be the impacts of future atmospheric CO2 concentrations. Many segments of today’s climate system exhibit unprecedented changes, at least compared to those observed in historical and instrumental records, leading to concern about “tipping points” or thresholds in the climate system. Paleoclimate records of abrupt transitions are useful to assess the causes and impacts of today’s decreasing Arctic sea ice and, in lower latitudes, hydrological changes and droughts.

Conclusions Modern atmospheric CO2 concentrations are approaching 400 ppmv, and future levels will far surpass the highest concentrations of the last 800,000 years as measured in ice core records. Research on past climate changes, especially patterns, causes and impacts of abrupt climate transitions, elevated atmospheric CO2 concentrations, and perturbations to the global carbon cycle, shows that Earth’s climate is extremely sensitive to large and small forcing over all timescales. Despite

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major progress over the past few years, future work is expected to add considerably to our understanding of how terrestrial and oceanic ecosystems respond to largescale climate changes such as those expected over the next few centuries from elevated greenhouse gas concentrations.

Cross-References ▶ Holocene Climate

References Bradley RS (1999) Paleoclimatology: reconstructing climates of the quaternary, 2nd edn. Academic, Amsterdam Cronin TM (2009) Paleoclimates: understanding climate change past and present. Columbia University Press, New York Jouzel J, Masson-Delmotte V, Cattani O, Dreyfus G, Falourd S, Hoffmann G, Minster B, Nouet J, Barnola JM, Chappellaz J, Fischer H, Gallet JC, Johnsen S, Leuenberger M, Loulergue L, Luethi D, Oerter H, Parrenin F, Raisbeck G, Raynaud D, Schilt A, Schwander J, Selmo E, Souchez R, Spahni R, Stauffer B, Steffensen JP, Stenni B, Stocker TF, Tison JL, Werner M, Wolf EW (2007) Orbital and millennial Antarctic climate variability over the past 800,000 years. Science 317(5839):793–796. doi:10.1126/science.1141038 Lisiecki LE, Raymo ME (2005) A Pliocene-Pleistocene stack of 57 globally distributed benthic d18O records. Paleoceanography 20:PA1003. doi:10.1029/2004PA001071 Loulergue L, Parrenin F, Blunier T, Barnola J-M, Spahni R, Schilt A, Raisbeck G, Chappellaz J (2007) New constraints on the gas age-ice age difference along the EPICA ice cores, 0–50 kyr. Clim Past 3:527–540. doi:10.5194/cp-3-527-2007 L€uthi D, Le Floch M, Bereiter B, Blunier T, Barnola J, Siegenthaler U, Raynaud D, Jouzel J, Fischer H, Kawamura K, Stocker TF (2008) High-resolution carbon dioxide concentration record 650,000–800,000 years before present. Nature 453:379–382. doi:10.1038/nature06949 Parrenin F, Barnola J-M, Beer J, Blunier T, Castellano E, Chappellaz J, Dreyfus G, Fischer H, Fujita S, Jouzel J, Kawamura K, Lemieux-Dudon B, Loulergue L, Masson-Delmotte V, Narcisi B, Petit J-R, Raisbeck G, Raynaud D, Ruth U, Schwander J, Severi M, Spahni R, Steffensen JP, Svensson A, Udisti R, Waelbroeck C, Wolff E (2007) The EDC3 chronology for the EPICA Dome C ice core. Clim Past 3:485–497. doi:10.5194/cp-3-485-2007 Petit JR, Jouzel J, Raynaud D, Barkov NI, Barnola J-M, Basile I, Bender M, Chappellaz J, Davisk M, Delaygue G, Delmotte M, Kotlyakov VM, Legrand M, Lipenkov VY, Lorious C, Pe´pin L, Ritz C, Saltzmank E, Stievenard M (1999) Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antartica. Nature 399:429–436. doi:10.1038/20859 Ruddiman WF (2007) Earth’s climate: past and future, 2nd edn. W. H. Freeman, New York Siegenthaler U, Stocker TF, Monnin E, L€ uthi Dieter, Schwander J, Stauffer B, Raynaud D, Barnola J-M. Fischer H, Masson-Delmotte VC, Jouzel J (2005) Stable carbon cycle-climate relationship during the late. Pliestocene 310:1313–1317. doi:10.1126/science.1120130

7

Holocene Climate Heinz Wanner

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Millennial-Scale Variability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Multi-Decadal- to Multi-Century-Scale Variability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Keywords

Interglacial • Orbital forcing • Holocene thermal maximum • Neoglacial • Monsoon • Bond cycles • Meltwater flux • Meridional overturning circulation • Medieval climate anomaly • Little ice age

Definition Holocene climate was strongly determined by changing solar insolation (millennial scale) as well as by changing solar activity, large tropical volcanic eruptions, and the dynamics of the ocean thermohaline circulation (multi-decadal to multi-century scale). The present interglacial, the Holocene, has sustained the growth and development of modern human society. It started about 11,700 years before present (BP) with a rapid transition from the cold period called Younger Dryas to a subsequent, generally warmer period that showed relatively small amplitudes in the reconstructed temperature. However, the tropics and subtropics witnessed strong changes in the hydrological conditions.

H. Wanner Oeschger Centre, University of Bern, Bern, Switzerland e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_28, # Springer Science+Business Media Dordrecht 2014

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Millennial-Scale Variability At the millennial scale, climate variability is strongly determined by the solar forcing that means the position and the orientation of the Earth relative to the Sun. As a consequence of the gravitational forces of the other planets (mainly Jupiter and Saturn) acting on the Earth, the orbital parameters of the Earth change with main periodicities around 400,000 and 100,000 years (due to changes in orbital eccentricity), 40,000 years (due to changes in the Earth’s axial tilt), and 20,000 years (due to the precession of the Earth’s axis). The theory of orbital forcing (often called Milankovitch theory) is unique in the sense that the orbital forcing is the only forcing that can be calculated precisely, even for the future (Berger 1978). The climate of the Holocene was strongly influenced by opposite hemispheric summer insolation trends. During the Holocene, the summer insolation of the Northern Hemisphere decreased by almost 40 W m 2, and an opposite trend existed in the Southern Hemisphere. Therefore, a strong shift in the hemispheric temperature distribution, as well as in the intensity of the monsoon systems, was observed (Wanner et al. 2008). Based on these facts, the Holocene can be divided into three main periods. The first period between approximately 11,700 and 7,000 years BP is characterized by a high summer insolation in the Northern Hemisphere, still a cool or temperate climate mainly in the surroundings of the melting ice sheets in North America and Eurasia (Renssen et al. 2009), and a high monsoon activity in Africa and Asia (Zhang et al. 2011). The second period between about 7,000 and 4,200 years BP marks the so-called Holocene Thermal Maximum (also called “Holocene Climate Optimum,” “Altithermal,” or “Hypsithermal” from a Northern Hemisphere viewpoint). Compared to the preindustrial period prior to year 1900 AD, this period was clearly characterized by higher summer temperatures in the Northern Hemisphere mid- and high-latitude areas, and most of the global monsoon systems were still active, but weakening (Wanner et al. 2008). The third period, called “Neoglaciation” or “Neoglacial,” was dominated by decreasing summer temperatures in the Northern Hemisphere due to decreasing insolation during the boreal summer (Denton and Karle´n 1973). Even though summer insolation in the Northern Hemisphere decreased after the mid-Holocene, there is evidence from some areas that not only the Holocene Thermal Maximum (Kaufman et al. 2004) but also the Neoglacial period started earlier. The Neoglacial was terminated by global warming, which at the beginning of the twentieth century was most likely induced by the increasing anthropogenic greenhouse effect (IPCC 2007). Figure 7.1 shows a spatial synthesis of Holocene climate change for the end of the third period, the Neoglacial (AD 1700), compared to the second period, the mid-Holocene Thermal Maximum (6,000 years BP). The dynamical response due to the decreasing solar insolation in the Northern Hemisphere is clearly visible. The ITCZ shifted south and a cooling trend, mainly during summer, occurred over the North Atlantic and its surrounding continental land mass. Therefore, the ice mass and the length of glaciers were smaller during the mid-Holocene, e.g., in the European Alps and Scandinavia, and many glaciers of the Northern Hemisphere

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reached a late maximum position during the so-called Little Ice Age (LIA) between AD 1350 and 1860. Reconstructions of the North Atlantic Oscillation (NAO) index, though uncertain, depict positive values and warmer winters for the mid-Holocene and negative values, indicating cold winters during the Neoglacial. The North Pacific sea surface temperature trend was positive, counter to the forcing, and humidity in the interior midlatitudinal area of North America increased. In the context of the southerly moving ITCZ (Haug et al. 2001), the Afro-Asian summer monsoon weakened greatly, causing aridity in subtropical Africa (e.g., the Sahel region), the northern Asian deserts, and in Central America. As a consequence of a changing sea surface temperature gradient between the Indo-Pacific warm pool and the eastern Pacific Ocean, the Walker circulation intensified after 5,000 years BP, and the frequency of the El Nin˜o increased. During the same period, a northward movement and a partial strengthening of the Southern Hemisphere westerlies occurred. The Antarctic temperatures remained constant or slightly cooled.

Multi-Decadal- to Multi-Century-Scale Variability Millennial-scale climate variability during the Holocene is superimposed by multidecadal to multi-century fluctuations or oscillations of the relevant state parameters, such as geopotential, temperature, and precipitation. The discussion about the dynamical background of this quasi-cyclical behavior of the Holocene climate system was stimulated by Bond et al. (2001). Based on their work, the expression “Bond cycle” was used to denote an oscillation during the last Ice Age whose period is equal to the time between successive Heinrich events (Bond and Lotti 1995; IPCC 2001). In their following studies, Bond and coauthors endeavored to find similar quasiperiodic cycles

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during the Holocene. They postulated the existence of a cycle with an average length of 1,470  500 years (Bond et al. 1997, 2001) and defined it as follows: “A prominent feature of the North Atlantic’s Holocene climate is a series of shifts in ocean surface hydrography during which drift ice and cooler surface waters in the Nordic and Labrador Seas were repeatedly advected southward and eastward, each time penetrating deep into the warmer strands of the subpolar circulation.” High peaks with fresh volcanic glass from Iceland or Jan Mayen and hematite-stained grains from eastern Greenland were interpreted to be the result of the southward and eastward advection of cold, ice-bearing surface waters from the Nordic and Labrador Seas during cold periods. Bond et al. (2001) postulated that this mechanism, being triggered by low solar activity, could also explain the temperature oscillations in the outer tropics during the Holocene. They defined totally nine quasiperiodic cycles with cold relapses mainly in the North Atlantic area and its surroundings. The consequence was that several authors tried to interpret negative temperature anomalies and even precipitation fluctuations in their Holocene time series as Bond cycles (Wanner and B€utikofer 2008). Recent studies show that one single dynamical theory explaining the formation of the Bond cycles does likely not exist and that Holocene multi-decadal to multi-century variability is very complex (Wanner et al. 2011). If we accept the abovementioned division of the Holocene into three periods, we may speculate that different dynamical processes were responsible for the quasi-cyclic climate oscillations. If we follow the abovementioned division into three time periods, we can distinguish different types of processes. During the first period, climate variability was strongly determined by the high summer insolation in the Northern Hemisphere and the resulting meltwater flux from the large ice sheets in Eurasia and North America. Mainly the strong, almost globally detectable cold relapse 8,200 years BP was with a high probability the effect of a damped meridional overturning circulation in the North Atlantic Ocean due to a massive meltwater flux from the Laurentide ice sheet. During the third period, called Neoglacial, several cold relapses were interrupted by multi-century long warm events (Wanner et al. 2011). In the Atlantic-European area, cold events occurred at 2,800 years BP, 350–750 AD (called Dark Age or Migration Period Pessimum), and 1350–1850 AD (called Little Ice Age). The best known warm events are the so-called Roman Warm Period between about 200 BC (before Christ) and 400 AD and the Medieval Climate Anomaly between about 900 and 1200 AD. The cooling episodes were most likely triggered by the low solar summer insolation during the Northern Hemisphere summer, in conjunction with a low solar activity and groups of large tropical volcanic eruptions. The corresponding patterns of temperature and precipitation were very complex, and mainly in the tropics and subtropics, humidity and precipitation were the critical parameters. This is particularly valid for the second (middle) period of the Holocene, e.g., the determining process of the cooling event between 6,500 and 5,900 years BP is still under debate. Interestingly, this event was connected with a declining activity of the Asian summer monsoon. A special interest is also centered on the transition between the Holocene Thermal Maximum and the Neoglacial period. The question is posed whether nonlinear feedback processes played a major role, and some authors argue (e.g., Debret et al. 2009) that the thermohaline circulation played a major role during the second part of the Holocene.

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Finally, the question must be asked whether we would still remain in the Little Ice Age or at least the early nineteenth-century climate regime today without the influence of the anthropogenic greenhouse effect. Further information can be gained from our Holocene Climate Atlas HOCLAT: http://www.oeschger.unibe.ch/research/projects/holocene_atlas/.

References Berger A (1978) Long-term variations of daily insolation and Quaternary climate changes. J Atmos Sci 35:2362–2367 Bond G, Kromer B, Beer J, Muscheler R, Evans MN, Showers W, Hoffmann S, Lotti-Bond R, Hajdas I, Bonani G (2001) Persistent solar influence on North Atlantic climate during the Holocene. Science 278:1257–1266 Debret M, Sebag D, Crosta X, Massei N, Petit J-R, Chapron E, Bout-Roumazeilles V (2009) Evidence from wavelet analysis for a mid-Holocene transition in global climate forcing. Quaternary Sci Rev 28:2675–2688 Denton GH, Karle´n W (1973) Holocene climatic variations – their pattern and possible cause. Quaternary Res 3:155–205 Haug GH, Hughen KA, Sigman DM, Peterson LC, Ro¨hl U (2001) Southward migration of the Intertropical Convergence Zone through the Holocene. Science 293:1304–1308 IPCC (Intergovernmental Panel on Climate Change) (2007) Climate change 2007: the physical science basis. Cambridge University Press, Cambridge/New York Kaufman D-S and 29 co-authors (2004) Holocene thermal maximum in the western Arctic (0- 180 W). Quaternary Sci Rev 23:529–560 PAGES SSC (2009) Past Global Changes, Science Plan and Implementation Strategy. IGBP Report 57, 67 pp Renssen H, Seppa¨ H, Heiri O, Roche DM, Goosse H, Fichefet T (2009) The spatial and temporal complexity of the Holocene thermal maximum. Nat Geosci 2:411–414 Wanner H, B€utikofer J (2008) Holocene bond cycles – real or imaginary? Geografie 4(113):338–349 Wanner H, Beer J, B€ utikofer J, Crowley TJ, Cubasch U, Fl€ uckiger J, Goosse H, Grosjean M, Joos F, Kaplan JO, K€ uttel M, M€ uller S, Prentice IC, Solomina O, Stocker TF, Tarasov P, Wagner M, Widmann M (2008) Mid- to late Holocene climate change: an overview. Quaternary Sci Rev 27:1791–1828 Wanner H, Solomina O, Grosjean M, Ritz SP, Jtel M (2011) Structure and origin of Holocene cold events. Quaternary Sci Rev 30:3109–3123 Zhang J, Chen F, Holmes JA, Li H, Guo X, Wang J, Li S, L€ u Y, Zhao Y, Qiang M (2011) Holocene monsoon climate documented by oxygen and carbon isotopes from lake sediments and peat bogs in China: a review and synthesis. Quaternary Sci Rev 30:1973–1987

8

Changes in Atmospheric Carbon Dioxide Hua Lin

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Knowing the Carbon Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Current Trends in Atmospheric Carbon Dioxide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fossil Fuel Combustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Land-Use Change CO2 Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CO2 Sinks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Predictions for the Future Scene of Atmospheric CO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

62 62 62 64 64 65 65 66 67 67

Abstract

Carbon cycles among the atmosphere, biosphere, pedosphere, geosphere, and hydrosphere. According to measurements, atmospheric CO2 concentration reached to 387 ppm by the end of 2009, which is 38 % above the preindustrial levels. And, it keeps increasing at an accelerated rate. A large amount of anthropogenic CO2 emitted into the air changes the balance between CO2 sources and sinks. Fossil fuel combustion emission occupied 85 % of the anthropogenic CO2 which is 41 % higher than in 1990. Another large contribution comes from land-use change. It is largely determined by deforestation in tropical regions. Combined emissions for fossil fuels and land-use change increase by over 3 % per year since 2000, up from 1.9 % over the period 1959–1999. The growth of these emissions is driven by population, per capital gross domestic product (GDP), and carbon intensity of GDP. Land and ocean sinks are vulnerable to climate change and land-use change. The land biosphere models showed a slight increase in global land CO2 sink between 1959 and 2008,

H. Lin Chinese Academy of Sciences, Mengla, Yunnan, China e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_48, # Springer Science+Business Media Dordrecht 2014

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with large year to year variability. However, the increasing rate of CO2 sinks cannot compensate the emission rate. Without carbon-free energy and new technologies to substitute the present energy, the trend of increasing CO2 emission will not be stabilized. Keywords

CO2 change • CO2 emission • CO2 sink • Fossil fuel emission • Anthropogenic CO2

Definition Atmospheric CO2 concentration is increasing at an accelerated rate. Although there are some uncertainties for land and ocean sinks, anthropogenic CO2 emission is the primary drive for this trend.

Knowing the Carbon Cycle CO2 is a naturally occurring chemical compound in the Earth’s atmosphere. It functions as a blanket that elevates the temperature of the earth. Carbon maintains a balance by cycling among the sources and sinks in the atmosphere, biosphere, pedosphere, geosphere, and hydrosphere. This balance is impacted by human activities and the dynamics of a number of terrestrial and ocean processes that remove or emit CO2 (Fig. 8.1).

Current Trends in Atmospheric Carbon Dioxide Long-term monitoring of atmospheric CO2 concentration provided us with accurate and reliable data. Atmospheric CO2 was constant around 280 ppm between 1000 AD and 1800 AD. Then, it rose at a rapid rate since the industrial revolution. The mean growth rate of atmospheric CO2 for 2000–2008 was about 1.9 ppm per year, significantly higher than the earlier trends (1.3 for 1970–1979, 1.6 for 1980–1989, and 1.5 for 1990–1999). Consequently atmospheric CO2 concentration reached to 387 ppm by the end of 2009 (Fig. 8.2), which is 38 % above the preindustrial levels. Between 1959 and 2008, 43 % of each year’s CO2 emission remained in the atmosphere on average; the rest was absorbed by carbon sinks on land and in the oceans. In the past 50 years, the fraction of atmospheric CO2 increased from 40 % to 45 %. The concentration of atmospheric CO2 is determined by the balance between sources and sinks. Positive increase of atmospheric CO2 could be induced by several factors. First, human activities such as fossil combustion and land-use change have significantly increased the concentration of CO2 in the atmosphere. Second, high ambient CO2 might deduce CO2 uptake efficiency of both land and ocean sinks through ocean acidification, widespread changes in marine biota, and the limitation of CO2

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Fig. 8.1 Global carbon dioxide budget. Blue data are the means from 1990 to 2000; Red data are the means from 2000 to 2008. The data comes from IGBP for Global Carbon Project based on Le Que´re´ et al. (2009)

Fig. 8.2 The Keeling Curve of atmospheric CO2. Concentration data are from Mauna Loa Observatory

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fertilization on land. Third, warm climate El Nin˜o events could contribute to the positive change. Besides, the atmospheric CO2 concentration could be observed increasing on a timescale shorter than those regulating the rate of uptake of carbon sinks. We will analyze every element in carbon cycle to reveal the answer.

Fossil Fuel Combustion The industrial revolution changed our life as well as affected the concentration of CO2 in the atmosphere. Burning of fossil fuels accelerated the release rate of CO2 to the atmosphere. CO2 emissions from fossil fuel combustion and cement production were 8.7
0.5 Pg C year1 in 2008, an increase of 2.0 % in 2007, 29 % in 2000, and 41 % above emissions in 1990. Emissions increased at a rate of 3.4 % year1 between 2000 and 2008, compared with 1.0 % year1 in the 1990s. The largest CO2 emission sources are oil and coal combustion, followed by gas and a small contribution of cement. Non-Annex B countries of Kyoto Protocol (developing countries without emission limitation) emitted more CO2 than Annex B countries (developed countries with emission limitation) since 2006. However, per capital emissions continue to be led by developed countries paralleled by a shift of Annex B economic activity towards service. More consumed products in Annex B countries were imported from non-Annex B countries. The world gross domestic product is a key driver in the recent fossil fuel utility. Consequently, the global financial crisis that affected markets in 2008 also had an effect on the global CO2 emissions and probably explains the modest growth in emissions of 2.0 % since 2007, compared with the faster than average growth of 3.6 % year1 observed for 2000–2007. The increase of population and per capital income is also a driving force for CO2 emission. With the economy’s recovery, global emissions have increased again in 2010 (Friedlingstein et al. 2010).

Land-Use Change CO2 Emissions Land-use change-induced CO2 emissions are the second anthropogenic source of CO2, accounting for 15 % of the total anthropogenic carbon emissions. Deforestation, logging, fire, and intensive cultivation induced CO2 emission. On the other side, CO2 uptake by reforestation and the succession of abandoned pasture and cropland compensated part of CO2 emission. During 1990–2005, net LUC CO2 emissions were 1.5
0.7 Pg C year1, and tropical deforestation is the dominant contribution (Le Que´re´ et al. 2009). Fire is the primary reason that causes tropical deforestation after timber exploitation. LUC emissions for 2000–2009 (1.1
0.7 Pg C year1) are lower than their 1990s level (1.5
0.7 Pg C year1), although the difference is below the uncertainty in the data and methods (Friedlingstein et al. 2010). In 2008, there is 0.3 Pg C year1 decrease in fire emissions associated with deforestation. The largest reductions are in Southeast Asia (65 %) and tropical America (40 %). It is deduced that wet La Nin˜a conditions in 2008 probably limited fire use and deforestation rates in Southeast Asia, particularly in Indonesia.

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Temperate forest regrowth in Eurasia has increased at the rate of 0.2 Pg C year1 per decade since 1950s. For the first time, LUC emissions at temperate latitudes switched to a small net sink of CO2 since 2000.

CO2 Sinks Almost 60 % of CO2 emissions were sequestrated in the land and ocean sinks. The models estimated that the average uptake rates of land and ocean CO2 sinks are 2.6
0.9 and 2.2
0.4 Pg C year1 for 1990–2000, respectively, and slightly increased to 3.0
0.9 and 2.3
0.4 Pg C year1 for 2000–2008. The land biosphere models showed an increasing global land CO2 sink between 1959 and 2008, with large year to year variability. However, the increasing rate of CO2 sinks was lower than the emission rate; as a result the atmospheric CO2 keeps increasing. Some of the carbon reservoirs including frozen soils, northern peat, tropical peat, permafrost, and continental shelves are vulnerable to climate change. And forests are vulnerable to deforestation, drought, and wildfires. A lot of factors including upward flux, biological utilization of CO2, temperature, and ambient CO2 concentration can affect the strength of ocean sinks. The ocean zone between 40 and 60 in latitudes in both northern and southern hemispheres is a major sink for atmospheric CO2. Enhancing the ambient concentration of CO2 will lead to acidification of ocean, thus reducing CO2 uptake capacity. Contrary to this assumption, several models showed land and ocean CO2 sinks increased when increasing atmospheric CO2 concentration and no changes in climate. When models were forced by both increasing CO2 concentration and changes in climate, airborne fraction increased at a rate of 0.1 % year1. Meanwhile these simulations may not completely describe the true scenarios due to uncertainty, coarse resolution in the ocean, and errors in observed precipitation and radiation on land.

Predictions for the Future Scene of Atmospheric CO2 Anthropogenic CO2 is the main contribution to the CO2 change since industrial revolution. Models estimate that 496 Gt CO2 will be emitted from combustion of fossil fuel with existing infrastructure between 2010 and 2060, resulting in mean warming of 1.3  C above the preindustrial era (or 0.3–0.7  C greater than at present) and stabilization concentration below 430 ppm. By comparison, assumed continued expansion of fossil fuel-based infrastructure predicts cumulative emissions of 2,986–7,402 Gt CO2 during the remainder of this century, leading to warming of 2.4–4.6  C by 2100 and atmospheric concentrations of CO2 greater than 600 ppm (Davis et al. 2010). However, the world’s energy demand is expected to rise by 50 % by 2030, 80 % of that increase will depend on fossil fuels (oil, gas, and coal) (Davis et al. 2010). The primary threats posed by climate change are from the emissions from the future energy demand, unless carbon-free energy and new technology will be predominant in the coming years.

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Table 8.1 Summary of CO2 sources and sinks and their partition for all decades since 1960 and for 2008. The data were from Le Que´re´ et al. (2009) 1960–1970 1970–1980 Sources Pg C year1 Fossil fuel+ 3.1
0.2 4.7
0.3 cement 1.5
0.7 1.3
0.7 Land usea Sinks Pg C year1 Atmospheric 1.8
0.1 2.7
0.1 growth Ocean sink 1.5
0.4 1.7
0.4 Land sinkb 1.2
0.9 2.6
1.1 Residualb 0.1
1.3 1.1
1.4 Partitioning of total emissions Atmosphere 0.39
0.07 0.45
0.06 Ocean 0.33
0.10 0.29
0.08 Landd 0.28
0.12 0.26
0.10

1980–1990

1990–2000

2000–2008

2008

5.5
0.3

6.4
0.4

7.7
0.4

8.7
0.5

1.5
0.7

1.6
0.7

1.4
0.7

1.2
0.7

3.4
0.1

3.1
0.1

4.1
0.1

3.9
0.1

2.0
0.4 2.2
0.4 1.8
0.9 2.6
0.9 0.1
1.3 0.0c

2.3
0.4 2.3
0.4 3.0
0.9 4.7
1.2 0.3
1.3 1.2
1.5

0.48
0.05 0.40
0.04 0.45
0.04 0.39
0.04 0.29
0.07 0.28
0.06 0.26
0.05 0.24
0.05 0.23
0.09 0.32
0.07 0.29
0.06 0.37
0.06

a

Including both the release from deforestation, and cultivation of cropland soils, and the uptake from vegetation regrowth following afforestation, abandonment of agriculture, and recovery from logging b Including only the response to CO2 increase and climate change. The residual is most likely attributed to unaccounted variability in the land models, with a small part due to uncertainties in LUC (see main text) c The ocean and land sink are corrected to agree with observations over 1990–2000; thus, the residual is zero during this time period d Including both the land sink and the residual. The uncertainty is the quadratic sum of the uncertainty in atmosphere and ocean fraction

Conclusion We have presented the trend of the major elements in the carbon cycle (Table 8.1). Yet the total balance of global carbon cannot be precisely estimated because the land and ocean CO2 sinks are not quantified with enough accuracy. CO2 concentration in the atmosphere is measured directly, which is accurate and reliable. Carbon concentration is increasing rapidly in the recent 50 years which was dominated by anthropogenic CO2 emission. Without human activity, 20–35 % of today’s emissions will remain in the atmosphere for several centuries. GDP is tightly linked to current growth in global anthropogenic CO2 emission. It is unrealistic to stop economic development and cease building energy infrastructure. Satisfying growing demand for energy without producing CO2 emissions will require truly extraordinary development of carbon-free sources of energy, enhance energy use efficiency, and well manage the participation of CO2 emissions temporally and spatially. Thus, there is currently a great focus on “low-carbon living style.”

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References Davis SJ, Ken C, Damon MH (2010) Future CO2 emission and climate change from existing energy infrastructure. Science 329:1330–1333 Friedlingstein P, Houghton RA, Marland G, Hackler J, Boden TA, Conway TJ, Canadell JG, Raupach MR, Ciais P, Le Que´re´ C (2010) Update on CO2 emissions. Nature 3:811–812 Global Carbon Project (2009) Annual carbon budget update of the global carbon project. http:// www.globalcarbonproject.org/carbonbudget Le Que´re´ C, Raupach MR, Canadell JG, Marland G et al (2009) Trends in the sources and sinks of carbon dioxide. Nature 2:831–836

Additional Recommended Reading Carbon Dioxide Information Analysis Center (CDIAC) http://cdiac.ornl.gov Field CB, Raupach MR (2004) The global carbon cycle – integrating humans, climate, and the natural world, SCOPE 62. Island Press, Washington, DC Scientific Committee on Problems of the Environment (SCOPE) http://www.icsu-scope.org United Nations Educational, Scientific and Cultural Organization (UNESCO) http://portal.unesco. org/science/en/ev.php-URL_ID¼5296%26URL_DO¼DO_TOPIC%26URL_SECTION¼201.html; http://portal.unesco.org/en/ev.php-URL_ID¼43031%26URL_DO¼DO_TOPIC&URL_SECTION ¼201.html United Nations Environment Programme (UNEP) http://www.unep.org

Part II Global Change and Oceans Ursula M. Scharler

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Sea-Surface Temperature Thomas M. Smith

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SST Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SST and Climate Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Projected SST Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cross-References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

71 72 72 74 75 75

Keywords

Sea-surface temperature (SST) • El Nin˜o/Southern Oscillation (ENSO) • Climate

Definition Since the oceans cover over two thirds of the Earth’s surface, sea-surface temperature (SST) is a critical measure of global temperature change. Natural patterns of interannual ocean-climate interactions such as the El Nin˜o/Southern Oscillation (ENSO) show the influence of SST variations on climate. Over longer periods the global SST has been warming since at least the nineteenth century, coincident with warming over land and changes in the Earth’s radiation balance caused by a buildup of greenhouse gases. There is evidence that one consequence of the longer-period warming may be a change in the intensity and frequency of natural SST variations, which will alter climate variations associated with those SST variations. Understanding how global warming may influence interannual SST variations is critical for improving climate prediction.

T.M. Smith NOAA, SCSB, STAR, NESDIS, College Park, MD, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_38, # Springer Science+Business Media Dordrecht 2014

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SST Analyses Knowledge of SST variations is derived from a combination of satellite and in situ observations. Satellite observations adequate for accurate global analyses are available beginning 1981. The earliest satellite observations are based on infrared instruments alone. Since 2002 both infrared and microwave satellite instruments may be used to observe global SST. Infrared satellite-based observations may be biased due to clouds and atmospheric aerosols, while microwave observations may be biased due to precipitation. Therefore in situ data are also needed for the satellite period to perform large-scale bias adjustments to the satellite observations before analysis. Combined satellite and in situ analysis is described by Reynolds et al. (2007). In the satellite period in situ SST observations are from a combination of ship and buoy observations. Buoy observations tend to be more accurate than those from ships, but they alone are not always dense enough for adjustment of satellite-based observations. Analyses in the satellite period use a combination of the bias-adjusted satellite-based observations and the in situ observations. For the satellite-period analysis, data are weighted so that the more accurate satellite-based observations are given the greatest weight in the analysis. In situ observations are most important for bias adjustments and in regions where persistent cloud cover causes the loss of infrared-based observations. In the pre-satellite historical period, only in situ observations are available, mostly from ships. Because historical observations are made using a mix of different methods, they can be biased relative to each other. Bias adjustments have been developed to minimize the influence of such biases on the historical record (e.g., Rayner et al. 2006). The historical sampling is not nearly as good as that from satellites. Therefore, the historical period is typically analyzed using large-scale spatial statistics based on the satellite period. Such analyses may resolve most monthly to interannual variations with spatial scales of a few thousand kilometers or greater, and they can be used to assess many climate-scale variations. Data are sufficient for producing historical analyses beginning in the late nineteenth century. Here the extended reconstruction of SST (ERSST) described by Smith et al. (2008) is used to evaluate SST variations and their changes since the late nineteenth century.

SST and Climate Patterns For comparisons done here the ERSST anomalies are averaged spatially into several different regions over 1880–2010. To make comparisons of interannual and longer-period changes clearer, the monthly values are first averaged annually, and then a 5-year binomial smoother is applied to the time series of annual values. The 1900–1999 average is also removed from all time series. Climate modes are preferred patterns of climate anomalies that have been defined from analyses of climate data. They were first identified in the early twentieth century, as described in the review by Katz (2002). Modes tend to be seasonal and may have timescales from monthly to multi-decadal. They are somewhat artificial, since

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Average SST Anomalies 0.9

NINO 3.4 Global

0.6

°C

0.3

0.0 −0.3 −0.6 −0.9

1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Fig. 9.1 ERSST anomalies averaged globally and over the NINO 3.4 area

variations associated with different modes can influence the same region. However, they often represent statistically independent variations, and they provide a means for understanding different components of climate variations. As noted above, ENSO is an important natural mode of variation affecting climate. The SST anomalies averaged over the NINO 3.4 area (5 S–5 N, 170 W–120 W) is often used as an ENSO index. This smoothed index indicates ENSO activity over the entire period, along with a warming tendency in the NINO 3.4 area similar to the global warming tendency (Fig. 9.1). The warming tendency is not linear over the period. There is a period of warming from roughly 1910–1940, followed by a stable period, followed by more warming beginning roughly 1970. The global warming is apparently shifting the ENSO index, making strong warm episodes more likely and strong cool episodes less likely. Multi-decadal ENSO-like variations are discussed in more detail by Zhang et al. (1997). Because the ENSO index is an average over a relatively small region, there is some uncertainty in it before 1950 due to sparser data and uncertainties in the historical bias adjustment. Since 1950 data density and quality are much less of a problem, and the consistency of the two averages over that period suggests that the shifts in the ENSO index are valid. Besides ENSO, other important natural climate modes that are reflected in SST include the North Atlantic Oscillation (NAO) and the Pacific Decadal Oscillation (PDO), both of which influence the Northern Hemisphere extratropics. The Southern Hemisphere extratropics have been found to be influenced by an annular mode associated with the atmospheric pressure distribution in the region. For additional

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Average SST Anomalies 0.6

0.4

N.H. Tropics S.H.

°C

0.2

0.0

−0.2

−0.4

−0.6 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Fig. 9.2 ERSST anomalies averaged over the Northern Hemisphere extratropics, over the tropics, and over the Southern Hemisphere extratropics

discussions of climate modes, see the studies of Mantua et al. (1997); Thompson and Wallace (2000), and references therein. The climate modes produce characteristic spatial patterns and have timescales ranging from monthly to multi-decadal. In this review a cruder approach is used in order to condense the discussion. Averages of SST anomalies are computed for the Northern Hemisphere extratropics, the tropics, and the Southern Hemisphere extratropics (Fig. 9.2). All three areas have interannual variations along with multi-decadal warming. Interannual variations are strongest in the tropics, where ENSO is reflected. The multi-decadal variations are similar in all three regions, but the phase of the warming shifts. Warming early in the twentieth century occurs first in the Northern Hemisphere, then in the tropics, followed by the Southern Hemisphere. The late twentieth-century warming occurs first in the Southern Hemisphere, followed by the tropics, and then the Northern Hemisphere.

Projected SST Changes Changes in the atmospheric radiation balance due to increasing greenhouse gases, which are believed to cause the global warming, should be well mixed on these timescales because of the relatively rapid mixing in the atmosphere. The observed SST phase shifts between hemispheres may reflect interactions between natural

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modes of variability and the overall warming. For example, it is possible that ocean warming and circulation patterns interact with climate modes on multi-decadal timescales to distribute additional heat throughout the global oceans. Changes in SST may influence the atmospheric pressure, causing feedbacks from changes in surface winds, cloudiness, atmospheric humidity, and rainfall over the oceans. Because ocean circulations can have timescales of decades or longer, decadalscale lags between hemispheres can develop. Prediction of future SST variations depends on the ability of climate models to simulate natural climate modes and their interactions with changing SST. The most recent IPCC gives a comprehensive review of recent climate models (Randall et al. 2007). The current best climate models are able to develop variations similar to observed climate modes such as ENSO, NAO, and PDO. However the spatial patterns apparent in the models are not always where observations suggest they should be, which can affect air-sea interactions in long coupled model runs. The coupled models with greenhouse gas forcing are able to simulate global temperature changes similar to observed changes. However, due to shifts in model-simulated climate patterns, the present state-of-the-art coupled air-sea model may be most valuable for prediction of large-scale variations that are less sensitive to the placement of climate modes. Besides prediction, models can be valuable for identifying physical interactions important in climate variations. Shifts in a simulated climate pattern may limit its predictive skill, but the basic ocean–atmosphere processes may be similar to those operating in nature. The complete sampling of the model can therefore be used to diagnose the processes in some detail. Such model diagnostic studies, combined with observations, allow climate physics to be better understood and models to be improved. In spite of model limitations discussed above, they are valuable tools that can give insight into climate dynamics and large-scale climate variations caused by changes in the Earth’s radiation balance over time. The review by Meehl et al. (2007) indicates that global SSTs are likely to continue increasing, with greatest increases at high latitudes. Acknowledgments I thank R. W. Reynolds and P. A. Arkin for reviewing this document and making suggestions for improvements. The contents of this paper are solely the opinions of the author and do not constitute a statement of policy, decision, or position on behalf of NOAA or the US Government.

Cross-References ▶ Variations of Oceanic Heat Content

References Katz RW (2002) Sir Gilbert Walker and a connection between El Nin˜o and statistics. Stat Sci 17:97–112 Mantua NJ, Hare SR, Zhang Y, Wallace JM, Francis RC (1997) A Pacific interdecadal climate oscillation with impacts on salmon production. Bull Am Meteorol Soc 78:1069–1079

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Meehl GA, Stocker TF, Collins WD, Friedlingstein P, Gaye AT, Gregory JM, Kitoh A, Knutti R, Murphy JM, Noda A, Raper SCB, Watterson IG, Weaver AJ, Zhao Z-C (2007) Global climate projections. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate change 2007: the Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK/New York Randall DA, Wood RA, Bony S, Colman R, Fichefet T, Fyfe J, Kattsov V, Pitman A, Shukla J, Srinivasan J, Stouffer RJ, Sumi A, Taylor KE (2007) Climate models and their evaluation. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate change 2007: the Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK/New York Rayner NA, Brohan P, Parker DE, Folland CK, Kennedy JJ, Vanicek M, Ansell TJ, Tett SFB (2006) Improved analyses of changes and uncertainties in sea surface temperature measured in situ since the mid-nineteenth century: the HadSST2 dataset. J Climate 19:446–469 Reynolds RW, Smith TM, Liu C, Chelton DB, Casey KS, Schlax MG (2007) Daily high-resolution-blended analyses for sea surface temperature. J Climate 20:5473–5496 Smith TM, Reynolds RW, Peterson TC, Lawrimore J (2008) Improvements to NOAA’s historical merged land-ocean surface temperature analysis (1880–2006). J Climate 21:2283–2296 Thompson DWJ, Wallace JM (2000) Annular modes in the extratropical circulation. Part I: month-to-month variability. J Climate 13:1000–1016 Zhang Y, Wallace JM, Battisti DS (1997) ENSO-like interdecadal variability: 1900–93. J Climate 10:1004–1020

Variations of Oceanic Heat Content

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Matthew D. Palmer

Contents Ocean Heat Content and Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Observations of Ocean Heat Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Understanding Past Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Projections of Ocean Heat Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

Variations in global and regional ocean heat content occur both due to natural variability and external forcing of the climate system. While regional patterns can be dominated by natural variations on decadal timescales, globally integrated ocean heat content responds primarily to external forcings such as anthropogenic global warming and major volcanic eruptions. The spatial patterns of future ocean heat content change and sea level rise (associated with ocean thermal expansion) depend both on changes in air-sea heat fluxes and systematic changes in ocean circulation. Keywords

Ocean heat content • Ocean circulation • Temperature • Climate change • Climate variability • Sea level

Ocean Heat Content and Climate The ocean’s ability to store and transport large quantities of heat plays a key role in regulating weather and climate over a range of timescales. The average depth of the open ocean is about 4 km, yet the upper few meters are approximately equal to the

M.D. Palmer Met Office Hadley Centre, Exeter, UK e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_67, # Springer Science+Business Media Dordrecht 2014

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heat capacity of the entire volume of the Earth’s atmosphere (Gill 1982). The storage and release of heat over the annual cycle accounts for the much smaller seasonal surface temperature range over the ocean compared to the land (Gill 1982). Like the atmosphere, the ocean is responsible for transporting vast quantities of heat toward the poles, which reduces the equator-to-pole temperature gradient associated with the differential solar heating that arises from the Sun-Earth geometry (Trenberth and Caron 2001). Large poleward oceanic heat transport is associated with mid-latitude winddriven current systems in the upper ocean – such as the Gulf Stream in the North Atlantic, the Kurushio in the North Pacific, and Agulhas in the South Indian – that carry warm subtropical waters toward the high latitudes and cooler waters equatorward. In the Atlantic, ocean heat transport is dominated by the thermohaline circulation, which results in northward net heat transport throughout the basin and contributes to the mild climate of Western Europe. The thermohaline circulation is believed to have exhibited abrupt changes in the past and the stability of the circulation under future climate change is the subject of ongoing research. Due to their enormous heat capacity, the global oceans represent by far the largest heat store in the Earth’s climate system. The long-term accumulation of energy in the Earth system can therefore be quantified, to good approximation, by measuring the long-term rise of global ocean heat content (Bindoff et al. 2007). While warming of other system components (e.g., the atmosphere, continents, and melting of terrestrial and marine ice) may have substantial climatic impacts, they are of secondary importance to the global energy budget (Bindoff et al. 2007). As seawater warms, it expands, and variations in ocean heat content play an important role in both global and regional changes in sea level. It has been estimated that changes in ocean heat content account for about 50 % of the observed sea level rise since the 1960s (Church et al. 2011). In addition, projections of global surface temperature rise are strongly dependent on how much heat is absorbed by the ocean under anthropogenic climate change (Boe´ et al. 2009).

Observations of Ocean Heat Content The ocean temperature measurements that are the basis of ocean heat content estimates are highly inhomogeneous in space and time. Historical subsurface observations are concentrated in the Northern Hemisphere and along major shipping routes – vast areas of the Southern Hemisphere and Southern Ocean were unobserved before the mid-2000s. Due to the scarcity of historical subsurface ocean temperature observations, most estimates of global ocean heat content changes only go back to the 1950s. At this time, many observations were limited to the upper 200–300 m. The first major advance in ocean heat content observations came about in the late 1960s and the development of the expendable bathythermograph (XBT). The widespread use of XBTs meant that routine temperature measurements of the upper 500–700 m could be made cheaply and from nonscientific vessels. These

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measurements constitute the majority of ocean temperature profiles for most of the historical record and facilitated some measurements up to about 1,500 m as deeper XBTs were developed over time. However, most XBT measurements were limited to major shipping routes and the instruments themselves were not designed for monitoring climate (Lyman et al. 2010). Shortly after the publication of the IPCC Fourth Assessment Report (AR4), it was discovered that there was a time-varying warm bias in the XBT measurements (Gouretski and Koltermann 2007). The result of this was to artificially inflate the decadal variability seen in observational estimates of global ocean heat uptake. Subsequent correction for this bias has led to better agreement between climate model simulations and observation-based time series (Domingues et al. 2008). However, there are a number of different approaches to correcting the XBT data and differences between correction methods remains a leading order uncertainty for estimating the time evolution of ocean heat content since the 1990s (Lyman et al. 2010). The inception of the ARGO array (http://www.argo.ucsd.edu/) of autonomous profiling floats in the early 2000s marked the first purpose-built system for real-time monitoring the global oceans, and has revolutionized our ability to observe the subsurface ocean. There are currently approximately 3,000 floats drifting freely in the ocean and reporting back temperature and salinity measurements for the upper 2,000 m with a 10-day repeat cycle. For many areas of the ocean, these are the first observations that have been recorded. It is only now that we are beginning to understand and quantify the seasonal cycle and variability in ocean heat content over the upper 2,000 m. Observations of oceanic heat over the full ocean depth are limited to a sparse set of hydrographic sections carried out by dedicated scientific research cruises. The World Ocean Circulation program (WOCE), which took place during the 1990s, was the first internationally coordinated global effort to characterize the physical properties and circulation of the world’s oceans over the full depth. Recent analysis of the WOCE observations and subsequent hydrographic sections suggests that increased heat content of the global abyssal waters (>4,000 m) and deep warming (1,000–4,000 m) of the Southern Ocean make a substantial contribution to global ocean heat uptake and sea level rise (Purkey and Johnson 2010).

Understanding Past Changes As previously discussed, the global ocean is the climate systems’ primary heat store. Therefore, changes in the convergence/divergence of energy into the Earth system due to “external forcings” (such as greenhouse gases and natural or anthropogenic aerosols) will leave their imprint in global ocean heat content. However, we can also expect unforced variations in global ocean heat content that arise from unforced “internal variability.” For example, during different phases of the El Nin˜o–Southern Oscillation (ENSO), the Earth system tends to emit more/less energy to space than it receives (Loeb et al. 2012). Historical estimates of ocean

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heat content change are shaped by both external forcings and internal variability but are also potentially subject to artifacts arising from the interplay between circulation changes and the limited, highly inhomogeneous observational sampling (Palmer et al. 2009). Despite these sampling issues, comparisons with climate model simulations suggest that variations in global and basin-scale ocean heat content in the upper few hundred meters are dominated by external forcing of the climate system. The main signals present in the observational record are long-term anthropogenic warming and episodic cooling events associated with natural volcanic activity (Domingues et al. 2008). The interannual variations in ocean heat content are sensitive to how XBT data are corrected, but all estimates agree qualitatively in the long-term warming (Lyman et al. 2010). However, recent work suggests that internal variability may be an important factor in the modest global surface temperature rise over the first decade of the twenty-first century through export of heat to the deeper ocean (Meehl et al. 2011). On regional scales, changes in air-sea heat fluxes, ocean advection, and mixing can all play an important role in determining decadal variations in local heat content. This is evidenced in the inhomogeneous spatial patterns of ocean warming, which show large local departures from the trend in global ocean heat content (Carson and Harrison 2010). In many cases, the drivers for regional heat content changes on decadal timescales are thought to be primarily associated with internal variability of the climate system and therefore likely to represent oscillations rather than long-term changes. For example, recent work has highlighted the importance of variations in the North Atlantic Oscillation in determining the patterns and mechanisms of ocean heat content change in the North Atlantic over the latter half of the twentieth century (Lozier et al. 2008). Coupled climate model simulations show that periods dominated by the La Nin˜a phase of ENSO, and widespread surface cooling of the tropical Pacific, may also be associated with an export of heat to the deeper ocean. Such periods can temporarily offset surface temperature rise under greenhouse gas scenarios (Meehl et al. 2011). The widespread warming observed in the Southern Ocean over the twentieth century is thought to be at least partly related to changes in atmospheric circulation associated with the Southern Annular Mode and corresponding poleward migration of ocean fronts (Gille 2008).

Projections of Ocean Heat Content In terms of temperature change, the projected changes from AR4 (Meehl et al. 2007) show the largest signals for the upper few hundred meters (Fig. 10.1). This is largely the result of the density stratification of the mid-to-low latitude upper ocean, which tends to trap the additional heat near the surface. The warming signal, and associated thermal expansion, acts to increase the upper ocean stratification and reinforces the confinement of warming to the upper few hundred meters. At the high latitudes, in the areas where deep ocean waters are formed, the warming signal

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Fig. 10.1 Zonal means of change in oceanic temperatures ( C), shown as cross sections. Values are the multi-model means for the A1B scenario for three periods (a–c). Stippling denotes regions where the multi-model ensemble mean divided by the multi-model standard deviation exceeds 1.0 (in magnitude). Anomalies are relative to the average of the period 1980–1999 (Adapted from Fig. 10.7 of the IPCC Fourth Assessment Report (Meehl et al. 2007))

propagates into the ocean interior, but this deeper warming takes longer to accumulate (Fig. 10.1). Spatial patterns of full depth ocean heat content change over the twenty-first century show some robust features across the AR4 models. The greatest oceanic heat gain occurs between about 40 S and 50 S in the Indian and Atlantic sectors of the Southern Ocean (Fig. 10.2). This region of large ocean heat content change is associated with relatively modest surface temperature (“Surface Temperature”). The mid-to-low latitude Atlantic Ocean is also characterized by particularly large heat uptake. Changes in ocean heat content in regions of deep water formation in the North Atlantic subpolar gyre and in the Southern Ocean, adjacent to the Weddell and Ross Seas, do not show a consistent response in the AR4 models. Changes in the wind-driven ocean circulation are thought to be the dominant influence on ocean heat content changes in the Southern Hemisphere and the particularly large heat gain between 40 S and 50 S (Meehl et al. 2007; Sen Gupta et al. 2009). Similarly, the large heat uptake in the Atlantic Ocean may be related to the changes in the thermohaline circulation, which tend to weaken under anthropogenic global warming (Meehl et al. 2007). It is important to note that both changes in air-sea heat fluxes and changes in ocean circulation can have a role to

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Fig. 10.2 The spatial pattern of ocean content from the AR4 multi-model ensemble, under the SRES 1B scenario. The colors represent the multi-model mean change (J m 2) between 1980–2000 and 2080–2100. The contours show the mean value divided by the multi-model standard deviation. The thick black line shows the zonal total heat content change, with x-axis at the top left. Figure taken from Kuhlbrodt and Gregory (2012)

play in the regional patterns of projected ocean heat content changes and the associated sea level rise from thermal expansion. An important caveat to the AR4 projections is that the models are limited in their ability to represent ocean eddies (the “weather systems” of the ocean that are analogous to the high and low pressure systems we are familiar with in the atmosphere) and other small-scale processes, such as the deep water formation around the coast of Antarctica (Sen Gupta et al. 2009). Therefore, while we are confident about the projected widespread surface-intensified warming, the systematic response of the ocean currents is much less certain. Regarding the model representation of deep water formation, it is likely that the current generation of climate models underestimate the warming of the deepest ocean waters.

References Bindoff NL, Willebrand J, Artale J, Cazenave A, Gregory J, Gulev S, Hanawa K, Le Que´re´ C, Levitus S, Nojiri Y, Shum CK, Talley LD, Unnikrishnan A (2007) Observations: oceanic climate change and sea level. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate change 2007: the physical science basis. Contribution of working group I to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK/New York

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Boe´ J, Hall A, Qu X (2009) Deep ocean heat uptake as a major source of spread in transient climate change simulations. Geophys Res Lett 36:L22701. doi:10.1029/2009GL040845 Carson M, Harrison DE (2010) Regional interdecadal variability in bias-corrected ocean temperature data. J Climate 23:2847–2855 Church JA, White NJ, Konikow LF, Domingues CM, Cogley JG, Rignot E, Gregory JM, van den Broeke MR, Monaghan AJ, Velicogna I (2011) Revisiting the Earth’s sea-level and energy budgets from 1961 to 2008. Geophys Res Lett 38:L18601. doi:10.1029/2011GL048794 Domingues CM, Church JA, White NJ, Gleckler PJ, Wijffels SE, Barker PM, Dunn JR (2008) Improved estimates of upper-ocean warming and multi-decadal sea-level rise. Nature, 453:1090–1094. doi:10.1038/nature07080 Gill AE (1982) Atmosphere–ocean dynamics. Academic, New York Gille ST (2008) Decadal-scale temperature trends in the Southern Hemisphere ocean. J Climate 21(18):4749–4765 Gouretski V, Koltermann KP (2007) How much is the ocean really warming? Geophys Res Lett 34:L01610. doi:10.1029/2006GL027834 Kuhlbrodt T, Gregory JM (2012) Ocean heat uptake and its consequences for the magnitude of sea level rise and climate change. Geophys Res Lett 39:L18608. doi:10.1029/2012GL052952 Loeb NG, Lyman JM, Johnson GC, Allan RP, Doelling DR, Wong T, Soden BJ, Stephens GL (2012) Observed changes in top-of-the-atmosphere radiation and upper-ocean heating consistent within uncertainty. Nat Geosci 5:110–113. doi:10.1038/ngeo1375 Lozier MS, Leadbetter SJ, Williams RG, Roussenov V, Reed MSC, Moore NJ (2008) The spatial pattern and mechanisms of heat content change in the North Atlantic. Science 319:800–803 Lyman JM, Good SA, Gouretski VV, Ishii M, Johnson GC, Palmer MD, Smith DA, Willis JK (2010) Robust warming of the global upper ocean. Nature 465:334–337. doi:10.1038/ nature09043 Meehl GA, Stocker TF, Collins WD, Friedlingstein P, Gaye AT, Gregory JM, Kitoh A, Knutti R, Murphy JM, Noda A, Raper SCB, Watterson IG, Weaver AJ, Zhao Z-C (2007) Global climate projections. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate change 2007: the physical science basis. Contribution of working group I to the fourth assessment report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, UK/New York Meehl GA, Arblaster JM, Fasullo JT, Hu A, Trenberth KE (2011) Model-based evidence of deepocean heat uptake during surface-temperature hiatus periods. Nat Clim Change 1:360–364. doi:10.1038/nclimate1229 Palmer MD, Good SA, Haines K, Rayner NA, Stott PA (2009) A new perspective on warming of the global oceans. Geophys Res Lett 36:L20709. doi:10.1029/2009GL039491 Purkey SG, Johnson GC (2010) Warming of Global Abyssal and Deep Southern Ocean Waters between the 1990s and 2000s: contributions to Global Heat and Sea Level Rise Budgets*. J Climate 23:6336–6351. doi:http://dx.doi.org/10.1175/2010JCLI3682.1 Sen Gupta A, Santoso A, Taschetto AS, Ummenhofer CC, Trevena J, England MH (2009) Projected changes to the southern hemisphere ocean and sea ice in the IPCC AR4 climate models. J Climate 22:3047–3078. doi:http://dx.doi.org/10.1175/2008JCLI2827.1 Trenberth KE, Caron JM (2001) Estimates of meridional atmosphere and ocean heat transports. J Climate 14:3433–3443

Ocean Currents and Circulation and Climate Change

11

Henk A. Dijkstra

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Motivating Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Present-Day Ocean Circulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sensitivity of the MOC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Salt-Advection Feedback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Robustness of Multiple Equilibria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recent Developments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

86 86 86 86 88 89 90 92 93 94

Abstract

The Atlantic Ocean, in particular its Meridional Overturning Circulation (MOC), is sensitive to the patterns of atmospheric forcing, in particular to that of the freshwater flux. Relatively small changes in atmospheric conditions can therefore lead to a spectacular reduction (collapse) of the strength of the Atlantic MOC. As the timescale of a collapse is only a few decades, the associated changes in heat transport may have a large impact on European climate and society. In the fourth Intergovernmental Panel on Climate Change (IPCC) assessment report (AR4), global climate models (GCMs) project that changes in freshwater input due to global warming will only lead to a slight change in the strength of the Atlantic MOC at the end of this century. However, there have been recent developments which indicate that the Atlantic MOC may be more sensitive than these models suggest; in this overview we will present what is known and what lies ahead.

H.A. Dijkstra Department of Physics and Astronomy, Institute for Marine Atmospheric Research Utrecht, Utrecht University, Utrecht, Netherlands e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_37, # Springer Science+Business Media Dordrecht 2014

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Keywords

Ocean circulation • Climate change

Definition Climate change affects the global ocean circulation and consequently the meridional transport of heat. In the Atlantic, the Warm Gulf Stream (more precisely, the Meridional Overturning Circulation) transports warm surface waters from tropical regions northward which causes relatively warm climates in Northwest Europe. A decrease in the strength of the Warm Gulf Stream as a consequence of climate change might decrease this supply of heat, causing a regional cooling, and hence, the behavior of the Atlantic Ocean circulation is a crucial factor in climate change projections.

Introduction Motivating Questions One of the main breakthroughs in climate research of the last 50 years is the reconstruction of past temperatures (and other properties) from sediment cores and ice cores. Isotope analyses from ice cores on Greenland, for example, provide information on the local temperatures over the last 105 years. The local temperature anomalies (DT) with respect to the mean temperature over the last century are plotted in Fig. 11.1. Slow variations are associated with the development of the last ice age of which the maximum occurred around 25 kyr ago. What is fascinating in this plot are the relatively rapid transitions (e.g., between 50 and 20 kyr) with a peak-to-peak amplitude of about 10
C. A typical period of these oscillations is 1,500 years, and they are called Dansgaard-Oeschger (DO) events. The DO events indicate that rapid temperature changes, which are not directly related to the (solar) forcing of the system, may occur in the climate system. Further research has indicated that the DO events are associated with changes in deep ocean circulation in the North Atlantic (Clement and Peterson 2008). This motivates the main questions addressed in this paper, i.e.: • How did changes in the Atlantic Ocean circulation lead to rapid changes in climate on Greenland? • Can such a rapid change occur again in the near future, in particular due to the increase of atmospheric greenhouse gas concentrations?

The Present-Day Ocean Circulation On the large scale, the ocean circulation is driven by momentum fluxes (by the wind) and the tides and affected by fluxes of heat and freshwater at the oceanatmosphere interface. The buoyancy fluxes affect the surface density of the ocean

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Fig. 11.1 Temperature anomaly (with respect to the mean over the last 100 years) at a location in central Greenland as reconstructed (Andersen et al. 2004) from oxygen isotope analysis (1 kyr ¼ 1,000 year)

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water, and through mixing and advection, density differences are propagated horizontally and vertically. A cartoon of the North Atlantic Ocean circulation is provided in Fig. 11.2a. In the North Atlantic, the Gulf Stream transports relatively warm and saline waters northward. The heat is quickly taken up by the atmosphere, making the water denser. In certain areas (the Greenland Sea and the Labrador Sea), when there is strong cooling in winter, the water column becomes unstably stratified resulting in strong convection. The net result of this is the formation of a water mass called North Atlantic Deep Water (NADW), which overflows the various ridges that are present in the topography and enters the Atlantic basin. This NADW is transported southward at a depth of about 2–4 km, where it enters the Southern Ocean. Through upwelling in the Atlantic, Pacific, and Indian Ocean, the water is brought back to the surface. To close the mass balance, the water eventually is transported back to the sinking areas in the North Atlantic. In the Southern Ocean, bottom water is formed which has a higher density than NADW and therefore appears in the abyssal Atlantic. In the North Pacific no deep water is produced. Together, the deep water formation at high latitudes, the upwelling at lower latitudes, and the horizontal currents that feed these vertical movements are indicated (Wunsch 2002) as the global thermohaline circulation (THC). The part of the THC that can actually be measured is called the Meridional Overturning Circulation (MOC), which is the zonally integrated volume transport. The MOC is mainly responsible for the meridional heat transport. The strength and spatial pattern of the MOC are determined by density differences which set up pressure differences in the Atlantic. There are no observations available to

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Fig. 11.2 (a) Strongly simplified sketch of the North Atlantic Ocean circulation. In the Atlantic, warm and saline waters flow northward into the deep water formation areas causing a return transport with a dominant component in the western boundary (see http://www.noc.soton.ac.uk/ rapidmoc/). (b) Volume transports of the Atlantic MOC at 26
N as measured by the RAPIDMOCHA array (Cunningham et al. 2007)

reconstruct the pattern of the MOC, but its strength at 26
N in the Atlantic is now routinely monitored by the RAPID-MOCHA array (Cunningham et al. 2007). A four year time series of the MOC strength is shown in Fig. 11.2b indicating a mean of about 19 Sv with a standard deviation of 5 Sv (1 Sv = 106 m3/s). At 26
N the heat transport associated with the Atlantic MOC is estimated to be 1.2 PW (Cunningham et al. 2007). This heat is transferred to higher latitudes leading to a relatively mild climate over Western Europe, compared to similar latitudes on the eastern Pacific coast.

Sensitivity of the MOC Contrary to the Gulf Stream itself (which is to a large extent wind driven), the MOC is a sensitive element in the climate system.

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Fig. 11.3 Sketch to illustrate the salt-advection feedback. A freshwater anomaly in the northern part of the Atlantic causes a weakening of the MOC (red to blue arrows). As a consequence, less salt is transported northward from equatorial areas which amplifies the original freshwater anomaly

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The Salt-Advection Feedback The MOC is particularly sensitive to changes in freshwater forcing because of a positive feedback, the salt-advection feedback (Fig. 11.3). If there is a freshwater perturbation in the northern North Atlantic (e.g., through melting of the Greenland Ice Sheet or additional rainfall), the water will locally become less dense. This leads to a decrease in deepwater formation and hence a weaker MOC. The MOC then transports less salt northward, and hence, the original freshwater perturbation is amplified. The MOC also transports less heat northward, but this anomaly is weakened by the atmospheric damping. During the last ice age, there were periods during which large quantities of icebergs were discharged in the North Atlantic. Because of the salt-advection feedback, it is thought that the strength of the MOC decreased rapidly, and consequently it became colder on Greenland. The salt-advection feedback was already described in 1961 in a paper by Henry Stommel (Stommel 1961). The theoretical model of Stommel was a so-called two-box model (Fig. 11.4a), with an equatorial reservoir and a polar reservoir which are connected at the surface and at depth. The circulation between the two boxes is driven by the density difference between the boxes which in turn is determined by the exchange of heat and freshwater at the ocean-atmosphere surface. The strength of the MOC is indicated by C, and for C > 0, the surface circulation is directed from the equatorial to the polar reservoir as in Fig. 11.4a. The different steady flow solutions of this model, for which the value of C, versus the strength of the surface freshwater forcing (represented by a parameter Z2) show (Fig. 11.4b) that there exists a range of freshwater forcing for which two stable states exist. One state (left panel in Fig. 11.4c usually referred to as the “on state”) is temperature driven and C > 0, while for the other state (the “off state” with C < 0), the MOC is salinity driven. When the freshwater strength is increased (while being in the “on” state), the strength of the MOC decreases down to a point L2. Just for values of Z2 slightly larger than the value at L2, the MOC will collapse, and a situation without northern deepwater formation (the “off-state” state) will appear.

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Fig. 11.4 (a) Sketch of the two-box model in Stommel (1961). (b) Bifurcation diagram (C versus the freshwater forcing strength Z2). (c) Sketch of the two states of the Stommel (1961) model with the on state (left) and the off state (right)

When from the “off state” the freshwater forcing is decreased, this state will exist down to the value of Z2 at the point L1. For slightly smaller Z2, the MOC will restore to the “on state” which is the only state which exists for these values of Z2.

Robustness of Multiple Equilibria The 1961 paper by Stommel was neglected for a long time probably because the two-box model was thought to be highly idealized. However, in 1986, Frank Bryan showed that multiple steady states could occur in a then state-of-the-art threedimensional ocean model (Bryan 1986). In a hierarchy of ocean-climate models, the regime of freshwater forcing where the on state and off state occur can relatively be easily found (Dijkstra 2005). The technique is to add freshwater very slowly in the northern North Atlantic and monitor the strength of the MOC until the off state is found. Then the freshwater forcing is reduced up to the point where the on state is again found (Rahmstorf et al. 2005). In more advanced climate models, such as those used in the 4th assessment report of the IPCC, it has been difficult (if not impossible) to find off states of the MOC.

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Fig. 11.5 (a) Time series of the MOC in the ECHAM-OM1 model (Sterl et al. 2008), where 1 Sv of freshwater is added in the northern North Atlantic. (b) The difference in annual mean surface (2 m) temperature between year 2025 and year 2001 (
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In the ESSENCE project (Sterl et al. 2008), simulations were done with the ECHAM5OM1 model (developed by the Max Planck Institute for Meteorology in Hamburg) over the period 2001–2100. The freshwater anomaly used was 1 Sv (about the volume transport of all the rivers on Earth), and the MOC decreases strongly over a period of 30 years (Fig. 11.5a). After 25 years, the difference in surface temperature (compared to the year 2000) (Fig. 11.5b) shows indeed that the temperature over a large area in the

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North Atlantic has decreased by about 10
C. Although this transition is not one from an one state to an off state (but only a weakened on state), the results provide an indication of the impact of the weakening of the MOC.

Recent Developments Based on the results of the GCMs used for the IPCC-AR4, the multiple equilibria and MOC collapse issues were thought to be artifacts of the simplicity of oceanonly or ocean-climate models. When the MOC changes, also the surface forcing fields of the ocean will change (such as the heat flux, the freshwater flux, and the wind stress), and these ocean-atmosphere feedbacks may prevent multiple equilibria of the MOC to occur. However, the question arises which processes then oppose the salt-advection feedback. One direction of recent research has been to develop indicators for the multiple equilibrium regime of the MOC. Based on earlier work of Rahmstorf (1996) and de Vries and Weber (2005), a scalar indicator S was shown (Dijkstra 2007) to provide an accurate measure of the presence of a multiple equilibrium regime. S is based on the freshwater budget over the Atlantic basin and is given by S ¼ Fov ðys Þ  Fov ðyn Þ where Fov is the freshwater transport (in Sv) due to the MOC, and ys and yn are the southern and northern latitude of the Atlantic basin boundaries. It turns out that
|Fov(yn)|  |Fov(ys)| and hence S  Fov(ys), with ys  35 S. When S < 0, the MOC transports freshwater out of the Atlantic basin. Hence, when the MOC is weakened due to a freshwater perturbation, the freshwater export decreases, and consequently the Atlantic becomes fresher, and hence, this amplifies the original perturbation. In this way, S can be seen as an integral salt-advection feedback. In Huisman et al. (2010), it was shown that the sign of S can indeed be connected to the stability of the MOC, if the perturbation MOC pattern (due to freshwater perturbations) has the same spatial structure (but opposite sign) as the mean MOC. When S is computed for the equilibrium solutions of typical GCMs used in IPCC-AR4 (Drijfhout et al. 2010), it is found that for nearly all models S > 0. Based on the indicator, this would mean that the MOC in these models is not in a multiple equilibrium regime. This is consistent with the fact that it is difficult to determine an off state in these models. However, the reason that S > 0 in these models is that they have a large bias in the freshwater budget in the Atlantic mainly related to too strong evaporation over the Atlantic. Hence, the MOC has to import freshwater at its southern boundary to close the freshwater balance. On the other hand, when S is determined from observations and reanalysis products, all estimates so far (Hawkins et al. 2011) provide S < 0 (Fig. 11.6). The observational estimates of Weijer et al. (1999) follow from an inversion of WOCE data and provide the most negative value of S  0.2 Sv. The estimate

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Fig. 11.6 Estimates of S  Fov(ys) from observations and reanalysis project results, slightly modified from Hawkins et al. (2011)

from Huisman et al. (2010) is directly from one WOCE section and gives S  0.1 Sv. The one from Bryden et al. (2011) is at 24
S and gives a mean of S  0.13 Sv. The values from the different reanalysis products give values between 0.0 and 0.2 Sv and hence are consistent with the observational estimates (Fig. 11.6).

Summary and Discussion The Atlantic MOC is sensitive to freshwater perturbations due to the existence of the salt-advection feedback. The advective transport of salt by the circulation, the density dependence on salinity, and the fact that the circulation is driven by density differences cause this to be a robust feedback in the Atlantic Ocean circulation. In relatively simple ocean-only and ocean-climate models, this feedback causes the existence of a multiple equilibrium regime and hence simultaneous existence of an on and off state of the MOC under the same atmospheric forcing conditions. However, in GCMs as used in IPCC-AR4, it is difficult to find off states, and collapses of the MOC have not been determined. There are three arguments based on recent results to support the statement that the Atlantic MOC may be much more sensitive to freshwater anomalies than GCMs used in IPCC-AR4 indicate. The first point concerns the bias in the Atlantic freshwater budget of the GCMs as was mentioned in section “Recent Developments”. Because of this bias, the equilibrium MOC states appear to be in the unique regime, and hence, no transition to a collapsed state can occur. From observations (and also

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reanalysis results), the present-day MOC appears to export freshwater, and hence, an off state may exist (Fig. 11.6). The second argument is that the strength of the oceanatmosphere feedbacks is by far too weak to remove the multiple equilibrium regime as was recently shown in Den Toom et al. (2012). The last argument is that when ocean eddies are taking into account, the response of the MOC to freshwater anomalies turns out to be stronger than in the lower resolution models, such as those used in IPCC-AR4 (Weijer et al. 2012). New results from model simulations performed within the CMIP5 suite of models will provide new insight into the sensitivity to freshwater anomalies and possibility of collapse of the Atlantic MOC. We may expect some surprises over the next decades both from the model results and observations. Acknowledgments The author thanks his colleagues Wilbert Weijer (LANL, USA), Matthijs den Toom, Selma Huisman (IMAU, NL), Andrea Cimatoribus, and Sybren Drijfhout (KNMI, NL) for the interesting, productive, and very pleasant collaboration over the years on this topic.

References Andersen K and coauthors (2004) High-resolution record of Northern Hemisphere climate extending into the last interglacial period. Nature 431:147–151 Bryan FO (1986) High-latitude salinity effects and interhemispheric thermohaline circulations. Nature 323:301–304 Bryden HL, King BA, McCarthy GD (2011) South Atlantic overturning circulation at 24S. J Mar Res 69:38–55 Clement AC, Peterson LC (2008) Mechanisms of abrupt climate change of the last glacial period. Rev Geophys 46:RG4002 Cunningham SA, Kanzow T, Rayner D, Baringer MO, Johns WE, Marotzke J, Longworth HR, Grant EM, Hirschi JJ-M, Beal LM, Meinen CS, Bryden HL (2007) Temporal variability of the Atlantic meridional overturning circulation at 26.5 N. Science 317(5840):935–938 de Vries P, Weber SL (2005) The Atlantic freshwater budget as a diagnostic for the existence of a stable shut down of the meridional overturning circulation. Geophys Res Letters 32(9): L09606 Den Toom M, Dijkstra H, Cimatoribus A, Drijfhout S (2012) Effect of atmospheric feedbacks on the stability of the Atlantic meridional overturning circulation. J Climate 25:4081–4096 Dijkstra HA (2005) Nonlinear physical oceanography: a dynamical systems approach to the large scale ocean circulation and El Nino, 2nd revised and enlarged edition. Springer, New York, p 532 Dijkstra HA (2007) Characterization of the multiple equilibria regime in a global ocean model. Tellus 59A:695–705 Drijfhout S, Weber S, van der Swaluw E (2010) The stability of the MOC as diagnosed from model projections for pre-industrial, present and future climates. Climate Dynam 40:1–12 Hawkins E, Smith RS, Allison LC, Gregory JM, Woollings TJ, Pohlmann H, De Cuevas B (2011) Bistability of the Atlantic overturning circulation in a global climate model and links to ocean freshwater transport. Geophys Res Lett 38(10):L10605 Huisman SE, den Toom M, Dijkstra HA, Drijfhout S (2010) An indicator of the multiple equilibria regime of the Atlantic meridional overturning circulation. J Phys Oceanogr 40(3):551–567 Rahmstorf S (1996) On the freshwater forcing and transport of the Atlantic thermohaline circulation. Clim Dyn 12:799–811

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Rahmstorf S, Crucifix M, Ganopolski A, Goosse H, Kamenkovich I, Knutti R, Lohmann G, March R, Mysak L, Wang Z, Weaver AJ (2005) Thermohaline circulation hysteresis: a model intercomparison. Geophys Res Lett L23605:1–5 Sterl A, Severijns C, Dijkstra HA, Hazeleger W, van Oldenborgh GJ, van den Broeke M, Burgers G, van den Hurk B, van Leeuwen PJ, van Velthoven P (2008) When can we expect extremely high surface temperatures? Geophys Res Lett 35:L14703 Stommel H (1961) Thermohaline convection with two stable regimes of flow. Tellus 2:224–230 Weijer W, De Ruijter WPM, Dijkstra HA, Van Leeuwen PJ (1999) Impact of interbasin exchange on the Atlantic overturning circulation. J Phys Oceanogr 29:2266–2284 Weijer W, Maltrud M, Hecht M, Dijkstra H, Kliphuis M (2012) Atlantic Ocean circulation to Greenland Ice Sheet melting. Geophys Res Lett 39, L09606. doi:10.1029/2012GL051611 Wunsch C (2002) What is the thermohaline circulation? Science 298:1179–1180

Sea Ice

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Hugues Goosse

Contents Definition and Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Cross-References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Abstract

A long-term increase in the sea ice extent has been observed in the Arctic since about 10,000 years because of changes in Earth’s orbital parameters. On shorter time scales, additional perturbations are imposed by some other natural forcings and by changes in the heat transfer between sea ice, ocean, and atmosphere. Moreover, the recent decrease of the Arctic sea ice extent is partially due to human activities – the anthropogenic radiative forcing – which will potentially lead to an ice-free Arctic in summer in the decades to come. Although no decrease in the ice extent has been observed in the Southern Ocean over the last decades, a decrease similar to the one expected in the Arctic is simulated by climate models for the late twenty-first century in response to anthropogenic radiative forcing. Keywords

Sea ice area • Sea ice extent • Natural variability • Anthropogenic forcing • Arctic • Antarctic • Southern Ocean

H. Goosse Centre de recherches sur la terre et le climat Georges Lemaıˆtre, Earth and Life Institute, Universite´ Catholique de Louvain, Louvain, Belgium e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_34, # Springer Science+Business Media Dordrecht 2014

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Definition and Description Sea ice varies at all the time scales, from daily to millions of years, because of changes in natural forcings, because of the intrinsic dynamics of the atmosphere–ocean-sea-ice system, and, for the last decades and the future, as a response to human activities. As sea ice forms when temperature drops below the freezing point of sea water, it has been present at the surface of polar oceans in each relatively cold period of the Earth’s history. Over the past million years, its extent has varied between a coverage much higher than today during the major parts of the glacial periods and an Arctic Ocean that may have been seasonally ice-free during some of the warmest interglacial periods (Polyak et al. 2010). The number of records, however, is still too low to state with high confidence if and when such summer ice-free conditions have prevailed. For the early Holocene (roughly between 11,000 and 8,000 years ago), which corresponds to the warmest period in summer in the Arctic since the last glacial period, evidence suggests a large decrease of the ice extent but with likely some ice still remaining in summer (Funder et al. 2011). Since that period, the decrease in summer insolation in the Arctic, related to changes in Earth’s orbital parameters, has induced a long-term increasing trend of the ice extent, on which fluctuations on shorter periods are imposed. The sea ice decline observed over the last decades in all the regions of the (Fig. 12.1). Arctic is thus opposite to this long-term trend. For the period 1978–2006, the decrease of the ice extent amounts to 3 % per decade (Comiso and Nishio 2008; see also the figure). The changes are particularly large in summer and for the last 5 years as, since 2007, the sea ice extent in September (end of summer) remained more than 25 % below the mean value for the period 1979–2000. This reduced ice extent is associated with a large decrease of the area covered by the thick perennial ice (the one that survived at least one summer melt) at a rate of about 10 % per decade and with a related general thinning of the sea ice. In the Southern Ocean, the sea ice extent follows an opposite trend with a weak but significant increase of about 1 % per decade over the years 1978–2006 (Comiso and Nishio 2008). The increase in ice extent appears particularly strong in the Ross Sea area, while some other sectors, like the Bellingshausen Sea, display a decrease. On interannual to multidecadal time scales, natural forcings such as variations in the total solar irradiance (related to the activity of the sun) and major volcanic eruptions (which modify the optical properties of the atmosphere leading to a general cooling) induce changes in the ice extent in both hemispheres. Sea ice also responds directly to the changes in wind stress and in the heat fluxes associated with atmospheric and oceanic variability. For instance, the dominant mode of variability of the winter atmospheric circulation in the North Atlantic is referred to as the North Atlantic Oscillation (NAO) and is associated with changes in the strength and position of the westerly winds. In its positive phase, which corresponds

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Fig. 12.1 Sea ice extents (solid) and trends (dashed) in (a) the Northern Hemisphere in March (black) and September (red) and (b) the Southern Hemisphere in March (red) and September (black)

to stronger westerly winds at midlatitudes, an enhanced south-westerly atmospheric flow brings warm air to the Barents Sea and favors a reduction of the sea ice extent. By contrast, the more northerly winds in the Labrador Sea during this phase of the NAO induce a more extensive ice cover there (Deser et al. 2000). In the Southern Ocean, the Southern Annular Mode is the dominant mode of atmospheric variability and is also related to the strength of the westerly winds. Its positive phase is associated with a decreased ice extent in the Bellingshausen Sea and an increase in the Ross Sea (Lefebvre et al. 2004). Part of the recent sea ice extent decrease in the Arctic is likely due to those natural processes. Nevertheless, a human influence, mainly related to the observed increase in atmospheric greenhouse gas concentration, has also been robustly detected (Min et al. 2008). According to model studies, the anthropogenic forcing that has contributed to the global temperature increase since preindustrial era has a larger impact in the Arctic than at mid and low latitudes. This phenomenon, which is generally referred to as Arctic or polar amplification, is consistent with the temperature increase over the last decades in the Arctic at a rate two times higher than at the global scale. The polar amplification is due to various mechanisms among which the most classical one is the temperature-albedo feedback. The albedo, which is the ratio between reflected and incoming solar radiation, is very high for snow and ice. It reaches typically 0.5–0.9 compared with about 0.1 for the oceans. If the temperature increases, in response to a radiative forcing, for instance, the snow and ice tend to melt. Consequently, the albedo is reduced, more solar radiation is absorbed at the surface, and the temperature further increases amplifying the initial perturbation. In addition, changes in atmospheric and oceanic heat transport to the Arctic as well as in the cloud cover also play a role in this polar amplification.

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The climate model response to the anthropogenic forcing over the twentieth and twenty-first centuries is smaller in the Southern Ocean than in the Arctic. This can be related to the presence of a small ocean surrounded by continents in the North compared with a small continent surrounded by a large ocean in the South. In addition, this large ocean is connected to all the major oceanic basins by wide and deep openings. As the thermal inertia of the ocean is larger than the one of land, the inertia of the system is much higher in the South than in the North. This damps the response of the system to the observed perturbations during at least several decades to centuries. On the other hand, most models do simulate a weak decrease in the ice extent in the southern hemisphere over the last decades as a response to human activities; this decrease though is not significant in the majority of the models (Arzel et al. 2006). The observed increase in the ice extent appears in this framework due to the large natural climate variability in that region. This variability, which is related to changes in ocean and atmospheric circulations similar to those briefly mentioned above, could indeed mask the small signal forced by the increase in atmospheric greenhouse gas concentration during several decades. This interpretation is also consistent with the decrease of the ice extent in the Southern Ocean during the second half of the twentieth century suggested by several studies (Goosse et al. 2009) with the forced response of the system appearing only if long enough time series are analyzed. Unfortunately, consistent and accurate satellite records are available since 1979 only, and the uncertainties before that date are too large to confirm with high confidence such a decrease between 1950 and 2000. Some analyses also suggest an influence of the stratospheric ozone depletion above Antarctica (the famous ozone hole) on sea ice trends through modifications of the atmospheric circulation. Additional work, however, is still required to better understand the possible links, and there are still many remaining uncertainties on the processes responsible for the observed positive trend over the last decades. Sea ice extent is expected to decrease in both hemispheres during the twentyfirst century as a consequence of human activities (Arzel et al. 2006; Meehl et al. 2007). The magnitude of this decrease will depend on the future changes in greenhouse gas concentration in the atmosphere and in other anthropogenic forcings. It appears clear that the changes will be larger in the Arctic in summer, leading to a larger amplitude of the seasonal cycle there. This decrease could be characterized by rapid sea ice loss superimposed on the longer-term decreasing trend (Holland et al. 2006). Depending on the hypotheses selected, this may lead to an ice-free Arctic in summer as early as in the 2030s, much later or not even in the twenty-first century (Wang and Overland 2009). Using the A1B scenario for greenhouse gas and sulfate aerosol concentrations, which corresponds roughly to a doubling of CO2 concentration in 2100 compared with 2000, the decrease in sea ice extent in the Arctic in March (end of winter) averaged over 14 different models reached 15 % in 2080–2100 compared to 1980–2000 (Arzel et al. 2006). Considerable differences between the models themselves were noticed. This illustrates the uncertainties related to the representation of

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physical processes by climate models – the other main source of uncertainty in addition to the one associated with the future developments of anthropogenic emissions. For the same scenario A1B, the decrease in 2080–2100 compared with 1980–2000 in the Southern Ocean averaged over the 14 different climate models amounts to 50 % in March (end of summer) and to 20 % in September (end of winter). For the Southern Hemisphere, the ability of models to simulate adequately the present state of the system is lower than in the Arctic. The scatter between the different projections is thus larger than in the Northern Hemisphere. Acknowledgments Hugues Gosse is Senior Research Associate with the Fonds National de la Recherche Scientifique (F.R.S.- FNRS-Belgium).

Cross-References ▶ Paleoclimates ▶ Radiative Forcing and the Greenhouse Gases ▶ Holocene Climate

References Arzel O, Fichefet T, Goosse H (2006) Sea ice evolution over the 20th and 21st centuries as simulated by current AOGCM. Ocean Model 12:401–415 Comiso JC, Nishio F (2008) Trends in the sea ice cover using enhanced and compatible AMSR-E, SSM/I, and SMMR data. J Geophys Res 113, C02S07. doi:10.1029/2007JC004257 Deser C, Walsh JE, Timlin MS (2000) Arctic sea ice variability in the context of recent atmospheric circulation trends. J Climate 13(2):617–633 Funder S, Goosse H, Jepsen H, Kaas E, Kjær KH, Korsgaard NJ, Larsen NK, Linderson H, Lysa˚ A, Mo¨ller P, Olsen J, Willerslev E (2011) A 10,000 yr record of Arctic Ocean sea ice variability – view from the Beach. Science 333:747–750 Goosse H, Lefebvre W, de Montety A, Crespin E, Orsi A (2009) Consistent past half-century trends in the atmosphere, the sea ice and the ocean at high southern latitudes. Climate Dynam 33:999–1016 Holland MM, Bitz CM, Tremblay B (2006) Future abrupt reductions in the summer Arctic sea ice. Geophys Res Lett 33, L23503. doi:10.1029/2006GL028024 Lefebvre W, Goosse H, Timmermann R, Fichefet T (2004) Influence of the Southern Annular Mode on the sea-ice-ocean system. J Geophys Res 109, C090005. doi:10.1029/ 2004JC002403 Meehl GA, Stocker TF, Collins WD, Friedlingstein P, Gaye AT, Gregory JM, Kitoh A, Knutti R, Murphy JM, Noda A, Raper SCB, Watterson IG, Weaver AJ, Zhao Z-C (2007) Global climate projections. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate change 2007: the physical science basis. Contribution of working group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK/New York Min SK, Zhang X, Zwiers FW, Agnew T (2008) Human influence on Arctic sea ice detectable from early 1990s onwards. Geophys Res Lett 35, L21701. doi:10.1029/ 2008GL035725

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Polyak L, Alley RB, Andrews JT, Brigham-Grette J, Cronin TM, Darby DA, Dyke AS, Fitzpatrick JJ, Funder S, Holland M, Jennings AE, Miller GH, O’Regan M, Savelle J, Serreze M, St. Johnm K, White JWC, Wolff E (2010) History of sea ice in the Arctic. Quaternary Sci Rev 29:1757–1778 Wang M, Overland JE (2009) A sea ice free summer Arctic within 30 years? Geophys Res Lett 36, L07502. doi:10.1029/2009GL037820

Additional Recommended Reading Goosse H, Barriat PY, Lefebvre W, Loutre MF, Zunz V (2011) Introduction to climate dynamics and climate modeling. Online textbook. http://www.climate.be/textbook. Accessed 31 Oct 2011 IPCC (2007) In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate change 2007: the physical basis. Contribution of working group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK/New York, p 996 (pdf version available at www.ipcc.ch) National Snow and Ice Data Center. http://nsidc.org/

Ocean Acidification and Oceanic Carbon Cycling

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Dieter A. Wolf-Gladrow and Bjo¨rn Rost

Contents Atmospheric CO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Air-Sea CO2 Exchange and Ocean Carbonate Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rate of Surface Ocean Acidification and Regional Differences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Physical Carbon Pump and Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Impact of Ocean Acidification on Marine Organisms and Ecosystems . . . . . . . . . . . . . . . . . . . . . . . The Biological Carbon Pump and Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Take-Home Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

The concentration of atmospheric CO2 is increasing due to emissions from burning of fossil fuels and changes in land use. Part of this “anthropogenic CO2” invades the oceans causing a decrease of seawater pH; this process is called “ocean acidification.” The lowered pH, but also the concomitant changes in other properties of the carbonate system, affects marine life and the cycling of carbon in the ocean. Keywords

Anthropogenic CO2 • Seawater acidity • Saturation state • Climate change • Physical carbon pump • Global warming • Biological carbon pumps • Phytoplankton • Primary production • Calcification

D.A. Wolf-Gladrow (*) • B. Rost Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany e-mail: [email protected]; [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_79, # Springer Science+Business Media Dordrecht 2014

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Atmospheric CO2 Atmospheric CO2, measured as partial pressure (pCO2) in units of microatmosphere (matm), remained almost constant at about 280 matm from the year 1000 until the beginning of the industrial revolution at the end of the eighteenth century. Since then, pCO2 is rising and approached values more the 40 % higher than preindustrial. CO2 emissions are still increasing (currently >9 Pg C yr
1; Peters et al. 2012), and thus one has to expect pCO2 two to three times the preindustrial value for the end of this century (560–880 matm according to scenario B2 and A1F1; Nakicenovic et al. 2000).

Air-Sea CO2 Exchange and Ocean Carbonate Chemistry The surface ocean exchanges gases with the atmosphere. Net CO2 fluxes between air and water are driven by differences in pCO2 of the atmosphere and the equilibrium pCO2 of seawater at a given chemical composition and temperature; at equilibrium, these two partial pressures equal each other. Starting from an equilibrium state, an increase of atmospheric CO2 would lead to invasion of CO2 into the ocean. In contrast to other gases like oxygen or nitrogen, CO2 not just dissolves in seawater: it reacts with water to form true carbonic acid (H2CO3) that largely dissociates to bicarbonate (HCO3
) and hydrogen ions (H+). CO2 can also react with carbonate ions (CO32
) to form HCO3
and H+. In both cases, the production of H+ results in an increase of the H+ concentration ([H+]) and thus to a decrease of pH, which is the negative logarithm of the H+ concentration (i.e., pH ¼
log10 [H+]). The change in [H+] influences the weak (not fully dissociated) acid–base systems in seawater, and thus the change in pH is smaller than expected from the simple stoichiometry of “one H+ per CO2 molecule added”. This buffering is due to high values of total alkalinity in seawater (TA ¼ [HCO3
] + 2 [CO32
] + [B(OH)4
]  minor components). Low-TA freshwater can take up much less CO2 and experiences large pH decrease even at small inputs of acid. For more details of the marine carbonate system, compare, for example, Zeebe and Wolf-Gladrow (2001).

Rate of Surface Ocean Acidification and Regional Differences The ocean currently takes up about one quarter of the anthropogenic CO2 emissions, causing surface ocean concentrations of CO2 and HCO3– to increase while CO32
and pH decrease (Fig. 13.1). The term “ocean acidification” summarizes the abovedescribed changes in the carbonate system, yet it is mostly used referring to the decrease in pH and [CO32
]. The term “carbonation,” on the other hand, relates to overall increase in dissolved inorganic carbon (DIC), in particular [CO2]. Assuming an atmospheric pCO2 of 750 matm for the end of this century (IS92a scenario, Nakicenovic et al. 2000), surface ocean [CO2] will have almost tripled relative to preindustrial concentrations. Concomitantly, [CO32–] and pH will have

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Fig. 13.1 Predicted changes in the surface seawater carbonate chemistry in response to changes in atmospheric pCO2 assuming the IS92a scenario (Modified after Wolf-Gladrow et al. (1999))

dropped by 50 % and 0.4 units, respectively. It should be noted that this drop in pH corresponds to an increase of 150 % in the H+ concentration. Such a rate of acidification is many times faster than whatever occurred over the last 55 Mio years (Ho¨nisch et al. 2012). Even though trends can be generalized for all oceans, different regions are differently affected by increasing pCO2. Polar waters, for instance, are most strongly affected by ocean acidification due to the higher solubility of CO2 in cold seawater. In the Arctic, the effect of freshening by rivers and sea ice melting (due to warming) intensifies the phenomenon even further because also TA is reduced in response to the higher freshwater input (Yamamoto-Kawai et al. 2009); hence the system is less buffered towards pCO2-induced pH changes. Upwelling systems, on the other hand, already today have pH values as low as those predicted for the end of this century (Feely et al. 2008). These examples, however, also illustrate that the present-day spatial variation in the carbonate chemistry is as high as the predicted changes in response to a doubling of atmospheric pCO2.

The Physical Carbon Pump and Climate Change Because of the fast changes in atmospheric CO2 concentrations, currently ocean acidification is primarily an upper ocean phenomenon. However, ocean

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circulation and mixing transfer the acidification signal also into intermediate layers and finally the deep ocean. This is due to the so-called “physical” or “solubility” carbon pump: the solubility of CO2 in seawater close to the freezing point is twice as high as in tropical surface water, and thus cold water contains large amounts of DIC. This cold, DIC-rich water sinks or is subducted in polar and subpolar regions filling the deep and intermediate ocean, by far the largest active carbon reservoir containing about 50 times more carbon than the atmosphere. The future uptake and storage of anthropogenic CO2 by the physical carbon pump can be estimated using mathematical models taking into account ocean circulation and physicochemical properties of seawater. A source of uncertainty is, however, current and future climate change including variations in ocean forcing due to wind stress, freshwater, and heat fluxes, all of which impact on the strength of the physical carbon pump (Le Que´re´ et al. 2007).

Impact of Ocean Acidification on Marine Organisms and Ecosystems While there is a high certainty about reasons and trends of ocean acidification, uncertainties remain with respect to many biological processes and the question, which organisms will belong to the losers and winners in future ecosystems. For marine primary producers, the increased availability of DIC may potentially be beneficial and a number of studies have indeed observed increased photosynthetic carbon fixation under elevated pCO2 (e.g., Tortell et al. 2008). Such “CO2 fertilization” effects have been attributed to increased diffusive CO2 supply for photosynthesis and/or reduced costs associated with active carbon acquisition (e.g., Kranz et al. 2010). Ocean acidification effects on primary production and growth are, however, strongly modulated by other environmental conditions (e.g., irradiance, nutrients) and cannot be generalized. While certain groups like cyanobacteria or sea grass appear to benefit strongly, the responses in diatoms, for instance, seem to be relatively small. In natural diatom-dominated assemblages, ocean acidification nonetheless induced pronounced species shifts (Tortell et al. 2008), illustrating that even small CO2-dependent changes in growth and primary production can have large ecological consequences. For calcifying organisms, by now there is good evidence that corals, gastropods, or coccolithophores (calcifying microalgae) will suffer from ocean acidification (Kroeker et al. 2010). Lowered calcification rates were attributed to the decrease in pH (and the concomitant higher costs of internal pH regulation), or they were related to [CO32
], which sets the saturation state (O) for carbonate minerals. Under present-day conditions, most surface waters are oversaturated with respect to calcite or aragonite and hence biogenic precipitation of these minerals is thermodynamically favored. With ocean acidification, however, the degree of saturation of surface waters is decreasing and polar waters, for instance, will become undersaturated within this century (Orr et al. 2005). This means not only that the production is less favored but also that skeletons are prone to dissolution.

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The higher corrosiveness of seawater may also explain why the bioerosion of coral reefs is accelerated under ocean acidification (Wisshak et al. 2012). Overall, it is very likely that lowered calcification in response to ocean acidification affects the competitive abilities of calcifiers. In line with this, the number of calcifying organisms was found to be significantly lower at volcanic CO2 vents compared to the nonacidified surrounding (Hall-Spencer et al. 2008). Fish and non-calcifying invertebrates also respond to ocean acidification, even though their sensitivity is generally much smaller than in calcifiers or primary producers. The higher tolerance to ocean acidification could be attributed to the fact that heterotrophic organisms exhibit a steep outward-directed CO2 gradient due to respiration; hence their acid–base regulation is used to deal with high CO2 conditions. Nonetheless, ocean acidification was shown to narrow down the aerobic scope of many animals, possibly due to higher costs involved in acid–base regulation and limitations in respiratory system to supply sufficient oxygen (Po¨rtner and Farrell 2008). As a consequence of this, the tolerance towards high temperatures is decreased under ocean acidification. This is especially troublesome for polar species as warming will be more severe than in other areas, and the organisms cannot refuge to colder regions. It also appears that juveniles and larval stages, which typically have a lower capacity for acid–base regulation, are more prone to ocean acidification than adults. As illustrated, ocean acidification was shown to impact organisms from different trophic levels with potentially large consequences for the marine ecosystem as well as carbon cycling. For more details of biological impacts compare, for example, Gattuso and Hansson (2011).

The Biological Carbon Pump and Climate Change In addition to the physical carbon pump, two biological carbon pumps impact on the marine carbon cycling. Particulate organic carbon (POC) is produced by marine microalgae and transformed by a complex food web. Part of this POC sinks out of the upper ocean into deeper layers or even down to the ocean floor. Most of the organic material, however, is remineralized in the water column or at the ocean bottom, leading to an increase of DIC in the respective depths. The sum of these processes is called the “soft tissue pump” or “organic carbon pump”. In addition to POC, calcium carbonate precipitated mainly by coccolithophores and foraminifera is exported from the upper ocean; it is either archived in sediments, especially at low water depths, or dissolved in the deep ocean. The sum of these processes is called the “calcium carbonate pump.” Both biological carbon pumps contribute strongly to a vertical DIC gradient, and without the biological carbon pumps, preindustrial atmospheric pCO2 would have been about twice as high (Maier-Reimer et al. 1996). Given the importance of the biological pumps for atmospheric pCO2, one would like to know how its functioning may change in a future ocean. The three main stressors for marine organisms and ecosystems are ocean warming, ocean acidification, and

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Fig. 13.2 Uptake of anthropogenic CO2 by the ocean leads to the strengthening of the physical carbon pump. Ocean acidification is a major stressor, besides ocean warming and deoxygenation, for marine organisms and ecosystems and thus also impacts on the biological carbon pumps. Arrows denote direction of impact, yet the full complexity of players and processes can only be indicated

deoxygenation (Gruber 2011). Some of the resulting effects are changes in nutrient supply by circulation and mixing, changes in light regime by stronger stratification, changes in calcification and primary production due to ocean acidification or carbonation, responses of animals due to altered fitness, or changes in amount and quality of food in a warmer and acidified surface ocean. They all have impacts on ecosystem structure and functioning and hence likely also alter the strength of the biological pumps. However, owing to the complex and mostly unknown interplay of stressors on the various processes (Fig. 13.2), a conclusive answer about magnitude and direction of change cannot be provided at this moment.

Take-Home Message Because of the fast increase of atmospheric CO2 and slow mixing of ocean waters, ocean acidification is first of all an ocean surface phenomenon. Effects of ocean acidification, e.g., undersaturation for aragonite, will occur first in polar waters,

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especially in the Arctic Ocean where low temperatures combine with freshening of surface waters. The physical carbon pump transports the acidification signal into deeper layers and is responsible for most of the uptake and storage of anthropogenic CO2. Climate change has a measureable impact on the physical carbon pumping. The biological carbon pumps are of central importance for the oceanic carbon cycling. Marine organisms show various responses to ocean acidification. Because of the complexity of the biological pumps, their responses to climate change and ocean acidification are thus far difficult to predict.

References Feely RA, Sabine CL, Hernandez-Ayon JM, Ianson D, Hales B (2008) Evidence for upwelling of corrosive “acidified” water onto the continental shelf. Science 320:1490–1492 Gattuso J-P, Hansson L (eds) (2011) Ocean acidification. Oxford University Press, Oxford, 326 pp Gruber N (2011) Warming up, turning sour, losing breath: ocean biogeochemistry under global change. Phil Trans R Soc A 369:1980–1996 Hall-Spencer JM, Rodolfo-Metalpa R, Martin S, Ransome E, Fine M, Turner SM, Rowley SJ, Tedesco D, Buia MC (2008) Volcanic carbon dioxide vents show ecosystem effects of ocean acidification. Nature 454:96–99 Ho¨nisch B, Ridgwell A, Schmidt DN, Thomas E, Gibbs SJ, Sluijs A, Zeebe R, Kump L, Martindale RC, Greene SE, Kiessling W, Ries J, Zachos JC, Royer DL, Barker S, Marchitto TM, Moyer R, Pelejero C, Ziveri P, Foster GL, Williams B (2012) The geological record of ocean acidification. Science 335:1058–1063 Kranz SA, Levitan O, Richter K-U, Pra´sˇil O, Berman-Frank I, Rost B (2010) Combined effects of CO2 and light on the N2 fixing cyanobacterium Trichodesmium IMS101: physiological responses. Plant Physiol 154:334–345 Kroeker KJ, Kordas RL, Crim RN, Singh GG (2010) Meta-analysis reveals negative yet variable effects of ocean acidification on marine organisms. Ecol Lett 13(11):1419–1434 Le Que´re´ C, Ro¨denbeck C, Buitenhuis ET, Conway TJ, Langenfelds R, Gomez A, Labuschagne C, Ramonet M, Nakazawa T, Metzl N, Gillett N, Heimann M (2007) Saturation of the Southern ocean CO2 sink due to recent climate change. Science 316:1735–1738 Maier-Reimer E, Mikolajewicz U, Winguth A (1996) Future ocean uptake of CO2: interaction between ocean circulation and biology. Climate Dynam 12:711–721 Nakicenovic N, Alcamo J, Davis G, de Vries B, Fenhann J, Gaffin S, Gregory K, Gr€ ubler A, Jung TY, Kram T, La Rovere EL, Michaelis L, Mori S, Morita T, Pepper W, Pitcher H, Price L, Raihi K, Roehrl A, Rogner H-H, Sankovski A, Schlesinger M, Shukla P, Smith S, Swart R, van Rooijen S, Victor N, Dadi Z (2000) Emissions scenarios. A special report of Working Group III of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK/New York, 599 pp Orr JC, Fabry VJ, Aumont O, Bopp L, Doney SC et al (2005) Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437:681–686 Peters GP, Marland G, Le Que´re´ C, Boden T, Canadell JG, Raupach MR (2012) Rapid growth in CO2 emissions after the 2008–2009 global financial crisis. Nat Clim Change 2:2–4 Po¨rtner HO, Farrell AP (2008) Physiology and climate change. Science 322:690–692 Tortell PD, Payne CD, Li Y, Trimborn S, Rost B, Smith WO, Risselsman C, Dunbar R, Sedwick P, di Tullio GR (2008) The CO2 sensitivity of Southern Ocean phytoplankton. Geophys Res Lett 35, L04605 Wisshak M, Scho¨nberg CHL, Form A, Freiwald A (2012) Ocean acidification accelerates reef bioerosion. PLoS ONE 7(9):e45124

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Wolf-Gladrow DA, Riebesell U, Burkhardt S, Bijma J (1999) Direct effects of CO2 concentration on growth and isotopic composition of marine plankton. Tellus B 51(2):461–476 Yamamoto-Kawai M, McLaughlin FA, Carmack EC, Nishino S, Shimada K (2009) Aragonite undersaturation in the Arctic Ocean: effects of ocean acidification and sea ice melt. Science 326:1098–1100 Zeebe RE, Wolf-Gladrow DA (2001) CO2 in seawater: equilibrium, kinetics, isotopes. Elsevier, Amsterdam, 346 pp

Other Nutrients and Dissolved Oxygen and Climate Change

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Katja Fennel

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cycling of Essential Elements in the Ocean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recent and Projected Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cross-References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Keywords

Nitrogen • Phosphorus • Silicate • Iron • Oxygen • N2 fixation • Denitrification • Deoxygenation • Hypoxia • Anoxia

Definition Primary and secondary production in the ocean depends on the supply of a few key elements. A combination of physical, chemical, and microbial processes mediates the cycling of these elements through the environment and determines their supply. Anthropogenic perturbations to the cycles of these elements, either directly or through global warming, could result in severe alterations of patterns of primary production and a reorganization of marine ecosystems.

K. Fennel Department of Oceanography, Dalhousie University, Halifax, NS, Canada e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_68, # Springer Science+Business Media Dordrecht 2014

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Cycling of Essential Elements in the Ocean The distribution and cycling of several key elements determines primary and secondary production and biogeochemical processes in the ocean; of particular interest are nitrogen (N), phosphorus (P), silicon (Si), oxygen (O), and the trace metal iron (Fe). All marine organisms require N and P as essential building blocks of their lipids, proteins, and carbohydrates. Si is only required by diatoms, a major group of unicellular marine algae that plays an important role in the biological carbon cycle. Diatom growth is typically limited by silicic acid. Fe is required only in trace amounts but necessary for the synthesis of a range of essential enzymes including those used in the photosynthetic apparatus. Free oxygen (O2), a by-product of photosynthesis, is essential for all multicellular heterotrophs and for many microbes as electron acceptor in the respiratory oxidation of organic matter. While there are other elements required for the synthesis of organic matter, cell walls, enzymes, etc. (first and foremost carbon but also sulfur, calcium, molybdenum, and others), these elements are typically available in sufficient amounts, thus their supply does not affect patterns of productivity in the modern ocean. Consequently anthropogenic perturbations in their cycling are not thought to be of first-order importance. The N cycle essentially consists of a number of redox reactions that transform a variety of N species, ranging in oxidation state from 3 to 5, from one form to another. The important inorganic species are the gaseous forms nitrogen gas (N2) and nitrous oxide (N2O) and the dissolved forms nitrate (NO3 ) and ammonium (NH4+). While N2 gas is extremely abundant, making up about 80 % of the Earth’s atmosphere and representing 99 % of all N in the ocean and atmosphere combined, it is biologically unavailable to most microorganisms. Only a specialized group, referred to as N2 fixers or diazotrophs, is able to split the stable triple bond in the N2 molecule and reduce it to bioavailable ammonium, which is readily incorporated in the synthesis of organic matter (ammonium and organic matter represent the most reduced forms of N with an oxidation state of 3). This process is referred to as N2 fixation. In the presence of free oxygen, ammonium is oxidized to nitrate (the most oxidized form of N with an oxidation state of 5; nitrate is also bioavailable to most microorganisms) by chemoautotrophic bacteria in a process referred to as nitrification. In the present, well-oxygenated ocean, the overwhelming majority of bioavailable N is present in its oxidized form as nitrate. In the absence of oxygen, certain heterotrophic bacteria can use nitrate as electron acceptor instead of oxygen for the respiration of organic matter. This process is referred to as denitrification and one of its end products is N2. Denitrification thus represents a sink for bioavailable nitrogen. N2O is an intermediate product during nitrification and denitrification and only present in small quantities but is of interest because it is a potent greenhouse gas. In summary, the N cycle in the modern ocean is mediated by three key processes – N2 fixation, nitrification, and denitrification – and is thus completely dependent on microbial activity. The balance of N2 fixation (source) and denitrification (sink) determines the oceanic reservoir of bioavailable nitrogen.

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The cycling of P differs from that of N in the following two major aspects. There is no P in the atmosphere, and P is found in only one oxidation state, as phosphate (PO4 ). The oceanic reservoir of phosphate is determined by the balance of river inputs from rock weathering (source) and removal due to permanent burial of organic matter in sediments (sink). Both of these processes are slow, leading to a much larger turnover time for phosphate in the ocean than for nitrate. The oceanic distributions of nitrate and phosphate are highly correlated, and their relative proportion of about 16 atoms of N per 1 atom of P matches the average composition of marine organic matter (C106N16P1) – an observation that was first articulated by Redfield in 1934 (the average relative ratios of elements in organic matter have since been referred to as Redfield ratios). This remarkable correspondence can be explained by the interplay of N2 fixation and denitrification, which, in an oxygenated ocean and over sufficiently long time scales, will regulate the oceanic inventory of bioavailable N to match the P inventory in terms of the Redfield ratio (Lenton and Watson 2000). In the modern ocean, there is only a slight deficit in nitrate with respect to phosphate, so N is typically the element limiting marine primary production. Si is required only by diatoms for their characteristic silica cell walls or frustules. Diatoms are very abundant and an important contributor to export of organic matter from the sunlit surface ocean to depth by sinking. Model-based estimates suggest that diatoms make up 40 % of the global export of particulate organic carbon (Jin et al. 2006). Fe, although required in much smaller quantities than N, P, and Si, is essential for many enzyme systems, including the photosynthetic apparatus and nitrogenase, the enzyme required for N2 fixation. Insufficient supply of Fe has been shown to limit primary production in the eastern equatorial Pacific, the subarctic Pacific, and the Southern Ocean. These areas are the so-called high-nutrient, low-chlorophyll (or HNLC) regions, where unused nitrate and phosphate remain present in surface waters at the end of the growing season. O2 is produced by photosynthesis and is consumed during aerobic respiration of organic matter (in terms of thermodynamic energy gain, O2 is the most beneficial electron acceptor). About 20 % of the Earth’s atmosphere consists of O2, which accumulated after the evolution of oxygenic photosynthesis early in the Earth’s history because some reduced organic carbon was stored in sedimentary rocks (at the ocean floor and on continental cratons) and thus effectively removed from the reduction-oxidation cycle. The modern ocean is also well-oxygenated, with relatively small oxygen minimum zones and anoxia occurring only in isolated spots with restricted circulation, e.g., the Cariaco Basin, the Black Sea, and the Baltic Sea. However, an oxygenated ocean is not an inevitable consequence of an oxygenrich atmosphere. There have been extended periods throughout the Earth’s history when the ocean was anoxic (Fennel et al. 2005). Below the sunlit surface ocean, the only source that offsets respiratory consumption of oxygen is physical transport of oxygenated water through convective mixing and thermohaline circulation. Since both of these physical processes are highly sensitive to climate, subsurface oxygen will likely be affected by climate change.

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The cycles of N, P, and O are linked and are also tightly coupled with the carbon cycle. One example illustrating the close coupling of N, P, and carbon cycling is the fact that oceanic nitrate and phosphate are available almost in Redfield proportions, as mentioned above. This regulation of nitrate availability can however be disrupted by a decrease in the O2 supply as described below.

Recent and Projected Changes Humans are massively perturbing the natural N cycle by adding bioavailable N through industrial N2 fixation for production of synthetic fertilizers, cultivation of leguminous crops, and fossil fuel burning. By 1990, anthropogenic sources of bioavailable N had exceeded the rate of natural N2 fixation in the terrestrial biosphere as well as the rate of marine N2 fixation; by 2050, anthropogenic production of bioavailable N is projected to exceed natural terrestrial and oceanic N2 fixation combined (Galloway et al. 2004). While application of synthetic fertilizers is necessary to feed the growing world population, inequalities in its distribution and inefficiencies in its use are pervasive. Some regions lack sufficient fertilizer to meet even the most basic caloric demands of millions of people, while elsewhere an excess of food leads to unhealthy diets and fertilizers are applied so inefficiently that they lead to eutrophication of aquatic environments (Galloway et al. 2008). Estimates suggest that about 80 % of anthropogenic N is denitrified in soils and freshwater systems and that the bulk of the remainder is denitrified on continental shelves (Fennel et al. 2006; Seitzinger et al. 2006). Hence, river inputs of anthropogenic N are likely not an important nutrient source for the open ocean yet lead to many negative effects in coastal waters including decreased water clarity, harmful algal blooms, and an increasing occurrence of hypoxia and anoxia (Diaz and Rosenberg 2008). In the open ocean, global warming is expected to lead to stronger vertical density stratification and a slowdown of the thermohaline overturning circulation, both of which would result in a decrease in O2 supply to waters below the sunlit surface. Evidence of this deoxygenation has already been reported (Stramma et al. 2008). If this trend continues, implications could be severe for deep-sea animals, especially benthic organisms with limited mobility. Ocean deoxygenation would also have biogeochemical consequences. In a hypoxic or anoxic ocean, denitrification would become more important as a pathway for the respiration of organic matter compared to aerobic respiration, which could result in a larger loss of bioavailable N than can be replenished by N2 fixation. This, consequently, would decrease the inventory of bioavailable N and reduce primary production globally. A massive increase in denitrification could also result in a significant additional source of the greenhouse gas N2O to the atmosphere, further amplifying global warming. Direct natural perturbations to the cycling of P, Si, and Fe are possible but would likely be smaller, at least over the next few hundred years. While dissolution and weathering of rocks is affected by climate (faster in warmer and more humid

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conditions), weathering rates are comparatively small. An expansion of arid regions and increase in the frequency of storms could accelerate Fe supply to the ocean, but this prediction is speculative. Variations in atmospheric Fe deposition to the ocean are thought to have occurred in concert with glacial/interglacial cycles in the past. In fact, these variations in Fe supply have been suggested to explain the glacial/ interglacial changes in partitioning of carbon between the atmosphere and ocean (Martin 1990), which has prompted geo-engineering proposals to apply large-scale fertilization of the ocean with Fe in order to mitigate future warming. Given the tight coupling of elemental cycles and the likelihood for unintended consequences, such proposals should be treated with caution.

Cross-References ▶ Ecological Carbon Sequestration in the Oceans and Climate Change ▶ Marine Net Primary Production

References Diaz RJ, Rosenberg R (2008) Spreading dead zones and consequences for marine ecosystems. Science 321:926–929 Fennel K, Follows M, Falkowski PG (2005) The co-evolution of the nitrogen, carbon and oxygen cycles in the Proterozoic ocean. Am J Sci 305:526–545 Fennel K, Wilkin J, Levin J, Moisan J, O’Reilly J, Haidvogel D (2006) Nitrogen cycling in the Mid Atlantic Bight and implications for the North Atlantic nitrogen budget: results from a threedimensional model. Global Biogeochem Cycles 20:GB3007, doi:10.1029/2005GB002456 Galloway JN, Dentener FJ, Capone DG, Boyer EW, Howarth RW, Seitzinger SP, Asner GP, Cleveland CC, Green PA, Holland EA, Karl DM, Michaels AF, Porter JH, Townsend AR, Vo¨ro¨smarty CJ (2004) Nitrogen cycles: past, present, and future. Biogeochemistry 70:153–226 Galloway JN, Townsend AR, Erisman JW, Bekunda M, Cai Z, Freney JR, Martinelli LA, Seitzinger SP, Sutton MA (2008) Transformation of the nitrogen cycle: recent trends, questions, and potential solutions. Science 320:889–892 Jin X, Gruber N, Dunne JP, Sarmiento JL, Armstrong RA (2006) Diagnosing the contribution of phytoplankton functional groups to the production and export of particulate organic carbon, CaCO3, and opal from global nutrient and alkalinity distributions. Global Biogeochem Cycles 20, GB2015, doi:10.1029/2005GB002532 Lenton TM, Watson AJ (2000) Redfield revisited 1. Regulation of nitrate, phosphate, and oxygen in the ocean. Global Biogeochem Cycles 14(1):225–248 Martin JH (1990) Glacial-interglacial CO2 change: the iron hypothesis. Paleoceanography 5(1):1–13 Redfield AC (1934) On the proportions of organic derivations in sea water and their relation to the composition of plankton. In: Daniel RJ (ed) James Johnstone memorial volume. University Press of Liverpool, pp 176–192, Liverpool Seitzinger S, Harrison JA, Bo¨hlke JK, Bouwman AF, Lowrance R, Peterson B, Tobias C, Van Drecht G (2006) Denitrification across landscapes and waterscapes: a synthesis. Ecol Appl 16(6):2064–2090 Stramma L, Johnson GC, Sprintall J, Mohrholz V (2008) Expanding oxygen-minimum zones in the tropical oceans. Science 320:655–658

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Additional Recommended Reading Capone DG, Bronk DA, Mulholland MH, Carpenter EJ (2008) Nitrogen in the marine environment (2nd edn). Academic Press, London Jacobson MC, Charlson RJ, Rodhe H, Orians GH (2000) Earth system science. Academic Press, London Sarmiento JL, Gruber N (2006) Ocean biogeochemical dynamics. Princeton University Press, Princeton

Marine Net Primary Production

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Zoe V. Finkel

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Net Primary Production (NPP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Controls on NPP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recent Trends in NPP: Global Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recent Trends in NPP: Regional Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Low Latitudes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coastal Middle Latitudes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . High Latitudes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Model Projections: NPP Over the Next Century . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cross-References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

Marine net primary production by phytoplankton fuels the marine food web. This chapter summarizes the primary controls on marine net primary production, recent temporal patterns in regional and global net primary production, and projections for net marine primary production over the next century. Keywords

Net primary production • Primary productivity • Climate change • Carbon cycle • Photosynthesis • Phytoplankton

Z.V. Finkel Environmental Science Program, Mt Allison University, Sackville, NB, Canada e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_42, # Springer Science+Business Media Dordrecht 2014

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Definition Net Primary Production (NPP) Net primary production (NPP) is the formation of organic material from inorganic compounds minus the respiratory losses of the photosynthetic organisms. Global marine annual NPP provides an estimate of the organic material available to fuel the ocean’s food webs for the year. The majority of NPP in the sea is generated by photosynthesis by phytoplankton: a polyphyletic group of photosynthetic prokaryotic and eukaryotic algal lineages. Satellite ocean color estimates of phytoplankton chlorophyll-a (the dominant pigment used to harvest light) are combined with models to estimate global NPP, while 14C incubations have been the most common method for estimating in situ NPP (for a review of these and other methods, see Cullen (2001)). Here we summarize controls on and recent patterns in NPP and model projections for how NPP will change over the next century. Currently satellite-based ocean color models estimate that annual mean net primary productivity is 407 mg C m 2 day 1 with a year-to-year standard error of 2.9 over 2003–2010 (data from www.science.oregonstate.edu/ocean.productivity following Behrenfeld and Falkowski (1997)). Integrated over the year marine NPP is 44 to 67 Gt of carbon, approximately half of total global NPP (Field et al. 1998; Westberry et al. 2008). Net primary productivity is spatially and temporally variable. Annual rates of marine net primary productivity are approximately lognormally distributed and range from a minimum value of 7.2 (0.8) to a maximum value of 12500 (212 sd) mg C m 2 day 1 and are typically lowest in the oceanic gyres and highest in upwelling zones along the coasts (Fig. 15.1). Regionally 21–46 % of NPP occurs in the high latitudes and Southern Ocean, 11–29 % occurs in the gyres, and 40–49 % occurs in the subtropical regions (Westberry et al. 2008). Within local regions NPP varies on daily, monthly, and decadal scales. For example, over 1985–2008 monthly mean daily net primary productivity in the Gullmar Fjord, Sweden, ranges from 50 to over 2000 mg C m 2 day 1 during the year, and mean annual production varies across years from a low of 182 to a high of 339 g C m 2 year 1 (Lindahl et al. 2009).

Controls on NPP Temporal and spatial trends in NPP are regulated by changes in environmental conditions that regulate phytoplankton growth including irradiance; inorganic nutrient concentrations, predominantly nitrogen, phosphorus, and iron; and temperature. For example, over significant areas of the equatorial and subarctic Pacific Ocean and parts of the Southern Ocean, low levels of iron deposition on the sea surface result in chronically low levels of phytoplankton biomass and NPP; ice cover, high winds, and resulting deep surface mixed layers result in low NPP due to chronic light limitation over large areas of the high latitudes for much of the year; nutrient upwelling zones fuel phytoplankton blooms and high NPP in many coastal regions and across the equatorial upwelling (Fig. 15.1). Loss processes such as

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Fig. 15.1 Annual NPP (mg C m 2 day 1) for 2008 estimated from ocean color and sea surface temperature (MODIS) using the Vertically Generalized Production Model following Behrenfeld and Falkowski (1997). Data courtesy of the Oregon Ocean Productivity Lab: http://www.science. oregonstate.edu/ocean.productivity/standard.product.php

grazing, viral and parasitoid attack, cell death, remineralization by bacteria and fungi, and sinking further regulate total net primary production through changes in the total standing stock of phytoplankton and the supply of nutrient.

Recent Trends in NPP: Global Analyses Year-over-year trends in NPP can be driven by natural physical forcing (patterns in atmospheric and ocean circulation, mixed layer dynamics) overlaid by anthropogenic perturbations including eutrophication of coastal regions and changes in CO2 and ocean pH and reduction of ozone over the poles. Climate change is expected to cause changes in the magnitude and temporal and spatial patterns in NPP, but over the short term may be difficult to detect over natural variability. Statistical analyses indicate an NPP time series of 40 years duration is required to unambiguously detect an anthropogenic climate change signal (Henson et al. 2010). Global analysis of ocean color indicates NPP has decreased between 1979–2002 and 1997–2006 (Gregg et al. 2003; Behrenfeld et al. 2006). Typical monthly changes in the NPP anomaly over the period of 1997–2007 are 1 mg C m 2 day 1 per year, with maximal changes on the order of 30–40 mg C m 2 day 1 per year (Henson et al. 2010). Gregg et al. (2003) found that much of the decrease in NPP over 1979–2002 (70 %) occurred in the high latitudes. In contrast NPP increased between 7 % and 14 % in 3 of the 4 low-latitude basins analyzed. Gregg et al. (2003) hypothesize the >10 % decline in NPP in the Antarctic is due to a combination of a decrease in iron deposition and increase in wind stress. Behrenfeld et al. (2006), using an ocean color model from 1997 to 2006, find a global decline in

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NPP starting in 1999 that is highly correlated with a multivariate El Nin˜o-Southern Oscillation index and hypothesize that this decline in global NPP (from 1999 to 2006) may be due to climate warming and increased stratification. Changes in NPP due to climate change is expected to be difficult to detect over natural interannual, decadal, and multi-decadal variability inherent in the NPP signal on the decade scale (Henson et al. 2010). Differences in the individual satellite data sets, calibrations used, and the temporal range of observations are likely responsible for some of the differences in results and conclusions between studies.

Recent Trends in NPP: Regional Analyses Low Latitudes Long-term measurements of NPP across the globe indicate changes in NPP over the last decades are complex and diverse. Increases in sea surface temperature in the subtropics are expected to increase surface water stratification, decrease nutrient supply to the surface, resulting in a decrease in NPP (Behrenfeld et al. 2006). In situ and ocean color-based model evidence for recent low-latitude decreases in NPP is equivocal (Gregg et al. 2003; Behrenfeld et al. 2006; Saba et al. 2010). A large decrease in primary productivity has been documented in the Cariaco Basin over the last 15 years as part of the Carbon Retention In A Colored Ocean (CARIACO) time series project (M€ uller-Karger et al. 2000). In contrast, NPP from in situ 14C tracer measurements at the Bermuda Atlantic Time-series Study site (BATS: 31 N, 64 W) and Hawaii Ocean Time-series site (HOT: 22 N, 158 W), both in subtropical gyres, has been increasing by 10 mg C m 2 day 1 year 1 from 1988 to 2006 (Saba et al. 2010). The decadal increases in NPP at these sites have been attributed to changes in subsurface water mass dynamics, changes in community composition, and increases in nitrite+nitrate availability in the surface (Saba et al. 2010).

Coastal Middle Latitudes Increases in the heat gradient between land and sea associated with climate warming are hypothesized to intensify wind-driven upwelling along areas of the coast and therefore stimulate increases in NPP. Significant increases in NPP have been detected along the California Current from 1997 to 2007, but are not positively correlated with wind stress (Kahru et al. 2009). Changes in nutrient inputs from the continents have had significant impacts on NPP in many coastal systems. For example, primary production in the northern Gulf of Mexico continental shelf has been linked to nutrient inputs from the Mississippi River over the 1980s and 1990s (Lohrenz et al. 1997). In the Baltic entrance region (the Kattegat and Belt Sea), annual NPP has increased from the 1950s to the 1980s and then decreased in the 1990s, attributed in part to changes in nutrient input from land, while higher rates since 1997 are attributed to changes in the methods used to

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measure carbon fixation (Rydberg et al. 2006). In the Wadden Sea at Marsdiep, annual NPP has increased since the 1960s, reaching a maximum in the 1990s, and decreasing from the 1990s to 2000 (Cadee and Hegeman 2002). In the Gullmar Fjord off the Swedish Skagerrak coast there is a 20 % increase in NPP from 1985 to a peak in 1992 through 1996 followed by a 25 % decrease to 2008 (Lindahl et al. 2009). The decadal patterns in NPP in the Gullmar Fjord have been attributed to decadal patterns in the North Atlantic Oscillation in conjunction with nutrient inputs and dynamics in the region (Belgrano et al. 1999; Lindahl et al. 2009).

High Latitudes Regional analyses of Arctic and Southern Ocean NPP indicate recent and projected increases in NPP with ice retreat and associated increases in the area of open water and the length of the phytoplankton growing season (Arrigo et al. 2008; Arrigo and Van Dijken 2011). In the Arctic, net primary production estimated from a satellite-based ocean color model has increased 20 % (441–585 Tg C per year) from 1998 to 2009 following increases in the duration of the open water season (Arrigo and Van Dijken 2011). As ice continues to retreat over the next decades, NPP in the Arctic could increase to 730 Tg C per year, depending on the availability of nutrients (Arrigo and Van Dijken 2011). In the Southern Ocean, NPP estimated from a satellite-based ocean color model from 1978 to 1986 averages 4,414 Tg C per year, with the highest values found in December in the Ross Sea (Arrigo et al. 2008). As ice melt continues in the Southern Ocean, NPP is expected to increase with increasing open water area, meltwater-induced stratification of surface waters near retreating sea ice edges, and input of micronutrients such as iron from the melt of ice (Smith et al. 2007). In situ measurements of primary production in these polar regions, especially the Southern Ocean, are sparse.

Model Projections: NPP Over the Next Century There is a lack of consensus of how NPP will change over the next century. Projections of NPP from ecosystem-biogeochemical models embedded into threedimensional ocean–atmosphere general circulation models range from global increases of >30 % to decreases of >10 % by 2100, depending on the model formulation (Bopp et al. 2005; Schmittner et al. 2008; Tagliabue et al. 2011). Models use a variety of different phytoplankton functional types and differ widely in the parameterization of their physiological response to environmental conditions and in some cases the environmental variables that influence growth rate. Only recently have general circulation models with biogeochemistry incorporated flexible elemental stoichiometry and the physiological response to changing pCO2 (Tagliabue et al. 2011). Most of the models agree that increases in air and sea surface temperature and resultant decreases in surface mixed layer depths and ice retreat are expected to

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cause increases in NPP in polar regions, while increased stratification in the subtropics is expected to decrease NPP due to a reduction in surface nutrient availability. Changes in mixed layer depth change irradiance as well as nutrient concentrations. While present models may include the observed increase and eventual saturation of photosynthetic rate with irradiance, the damaging effects of excess irradiance are often neglected. Although the costs associated with avoiding and mitigating photoinhibition are currently poorly quantified, they will impact growth rate and differ across species (Raven 2011) and therefore may contribute to biogeographic patterns in phytoplankton community composition.

Conclusions NPP is the food that fuels the ocean food web. Currently annual marine NPP is 44 to 67 Gt of carbon, similar to NPP on land. The impact of future climate change on NPP is unclear. Current expectation is that warming will result in an increase in NPP in polar latitudes due to a decrease in ice cover and increase in surface stratification and the availability of light. In the low-nutrient subtropical oceanic gyres, increased stratification is expected to lead to decreases in nutrient availability and decrease in NPP. Despite these generalities, there is a lack of consensus in model projections of NPP over the next century reflecting significant uncertainties in our understanding of how phytoplankton and NPP will respond to changing climate and other anthropogenic perturbations. Acknowledgments The work is funded by the Canada Research Chair and NSERC Discovery programs. I thank A. J. Irwin for his assistance with Fig. 15.1 and manuscript preparation.

Cross-References ▶ Ecological Carbon Sequestration in the Oceans and Climate Change ▶ Ocean Acidification and Oceanic Carbon Cycling ▶ Pelagic Ecosystems and Climate Change

References Arrigo K, van Dijken GL (2011) Secular trends in Arctic Ocean net primary production. J Geophys Res 116:1–15 Arrigo K, van Dijken GL, Bushinsky S (2008) Primary production in the Southern Ocean, 1997–2006. J Geophys Res 113:1–27 Behrenfeld MJ, Falkowski PG (1997) Photosynthetic rates derived from satellite-based chlorophyll concentration. Limnol Oceanogr 42:1–20 Behrenfeld MJ, O’Malley R, Siegel D, McClain C, Sarmiento J, Feldman G, Milligan A, Falkowski P, Letelier R, Boss E (2006) Climate-driven trends in contemporary ocean productivity. Nature (London) 444:752–755

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Belgrano A, Lindahl O, Hernroth B (1999) North Atlantic oscillation primary productivity and toxic phytoplankton in the Gullmar Fjord, Sweden (1985–1996). Proc R Soc Lond B 266:425–430 Bopp L, Aumont O, Cadule P, Alvain S, Gehlen M (2005) Response of diatoms distribution to global warming and potential implications: a global model study. Geophys Res Lett 32:1–4 Cadee GC, Hegeman J (2002) Phytoplankton in the Marsdiep at the end of the 20th century; 30 years monitoring biomass, primary production, and Phaeocystis blooms. J Sea Res 48:97–110 Cullen JJ (2001) Plankton: primary production methods. In: Steele J, Thorpe S, Turekian K (eds) Encyclopedia of ocean sciences. Academic Press, San Diego, pp 2277–2284 Field C, Behrenfeld M, Randerson J, Falkowski P (1998) Primary production of the biosphere: integrating terrestrial and oceanic components. Science 281:237–240 Gregg WW, Conkright ME, Ginoux P, O’Reilly JE, Casey NW (2003) Ocean primary production and climate: global decadal changes. Geophys Res Lett 30. doi:10.1029/ 2003GL0116889 Henson SA, Sarmiento JL, Dunne JP, Bopp L, Lima I, Doney SC, John J, Beaulieu C (2010) Detection of anthropogenic climate change in satellite records on ocean chlorophyll and productivity. Biogeosciences 7:621–640 Kahru M, Kudela R, Manzano-Sarabia M, Mitchell BG (2009) Trends in primary production in the California current detected with satellite data. J Geophys Res 114:1–7 Lindahl O, Andersson L, Belgrano A (2009) Primary phytoplankton productivity in the Gullmar Fjord, Sweden. An evaluation of the 1985–2008 time series. Swedish Environmental Protection Agency. Stockholm, Sweden, pp 1–35 Lohrenz SE, Fahnenstiel GL, Redalje DG, Lang GA, Chen X, Dagg MJ (1997) Variations in primary production of northern Gulf of Mexico continental shelf waters linked to nutrient inputs from the Mississippi River. Mar Ecol Prog Ser 155:45–54 M€uller-Karger F, Varela R, Thunell R, Scranton M, Bohrer R, Taylor G, Capelo J, Astor Y, Tappa E, Ho T-Y, Iabichella M, Walsh JJ, Diaz JR (2000) The CARIACO project: understanding the link between the ocean surface and the sinking flux of particulate carbon in the Cariaco Basin. EOS, AGU Trans 81:529 Raven JA (2011) The cost of photoinhibition. Physiol Plantarum 142:87–104 Rydberg L, Aertebjerg G, Edler L (2006) Fifty years of primary production measurements in the Baltic entrance region, trends and variability in relation to land-based input of nutrients. J Sea Res 56:1–16 Saba VS, Friedrichs MAM, Carr ME, Antoine D, Armstrong RA, Asanuma I, Aumont O, Bates NR, Behrenfeld MJ, Bennington V, Bopp L, Bruggeman J, Buitenhuis ET, Church MJ, Ciotti AM, Doney SC, Dowell M, Dunne JP, Dutkiewicz S, Gregg W, Hoepffner N, Hyde KJW, Ishizaka J, Kameda T, Karl DM, Lima I, Lomas MW, Marra J, McKinley GA, Melin F, Moore JK, Morel A, O’Reilly JO, Salihoglu B, Scardi M, Smyth TJ, Tang S, Tjiputra J, Uitz J, Vichi M, Waters K, Westberry TK, Yool A (2010) Challenges of modelling depth-integrated marine primary production over multiple decades: a case study at BATS and HOT. Global Biogeochem Cycles 24:1–21 Schmittner A, Oschlies A, Matthews HD, Galbraith ED (2008) Future changes in climate, ocean circulation, ecosystems, and biogeochemical cycling simulated for a business-as-usual CO2 emission scenario until year 4000 AD. Global Biogeochem Cycles 22:1–21 Smith KL Jr, Robison BH, Helly JJ, Kaufmann RS, Ruhl HA, Shaw TJ, Twining BS, Vernet M (2007) Free-drifting icebergs: hot spots of chemical and biological enrichment in the Weddell Sea. Science 317:478–482 Tagliabue A, Bopp L, Gehlen M (2011) The response of marine carbon and nutrient cycles to ocean acidification: large uncertainties related to phytoplankton physiological assumptions. Global Biogeochem Cycles 25:1–13 Westberry TK, Behrenfeld MJ, Siegel DA, Boss E (2008) Carbon-based primary productivity modeling with vertically resolved photoacclimation. Global Biogeochem Cycles 22:1–18

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Additional Recommended Reading Falkowski PG, Raven JA (2007) Aquatic photosynthesis, 2nd edn. Princeton University Press, Princeton, NJ Falkowski P, Laws EA, Barber RT, Murray JW (2003) Phytoplankton and their role in primary, new, and export production. In: Fasham MJR (ed) Ocean biogeochemistry: the role of the ocean carbon cycle in global change. Springer Berlin Heidelberg, New York, pp 99–121

Ecological Carbon Sequestration in the Oceans and Climate Change

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Richard Sanders and Stephanie Henson

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Biological Carbon Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Observing the Biological Carbon Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reduction of Sinking Carbon Flux with Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Controls on Carbon Sequestration in the Deep Ocean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Variability in the Biological Carbon Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Deliberate Manipulation of the Biological Carbon Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Climate Change Impacts on the Biological Carbon Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

125 125 126 127 128 129 129 130 131

Keywords

Biological carbon pump • Phytoplankton • Ocean primary production • Carbon dioxide • Geoengineering

Definition The biological carbon pump helps regulate the partitioning of carbon dioxide between the atmosphere and the ocean and is expected to play a fundamental role in future climate change.

R. Sanders (*) • S. Henson National Oceanography Centre, University of Southampton, Southampton, UK e-mail: [email protected]; [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_44, # Springer Science+Business Media Dordrecht 2014

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The Biological Carbon Pump The oceans contain massive quantities of dissolved carbon dioxide (CO2), partly as a result of the equilibration of the sea surface with the atmosphere and partly as a result of ocean biological processes. As atmospheric CO2 is increased by the anthropogenic input of fossil fuel CO2, the equilibration of the air and sea increases the amount of CO2 in the oceans. Biological processes also act to draw a large quantity of CO2 into the oceans. Indeed, without them atmospheric CO2 concentrations would be approximately 50 % greater than they currently are (Parekh et al. 2006). These biological processes, collectively known as the biological carbon pump (BCP), consist of the photosynthetic fixation of dissolved CO2 in the surface ocean by microscopic marine algae (phytoplankton), followed by the aggregation of some of this material and subsequent transfer to depth via sinking. This sinking flux is several times larger than the sequestration of anthropogenic carbon by the oceans; hence, a small change in the size of the BCP could radically affect atmosphereocean CO2 partitioning. The BCP also forms the basis of the marine food chain. A fraction of the organic carbon produced by phytoplankton is not exported but is instead consumed by higher trophic levels including crustacean zooplankton. In turn, these are consumed by fish larvae, and the energy is transferred up the food chain until it reaches commercially exploitable fish species. The importance of the BCP to fisheries and global carbon cycling drives a considerable scientific and political imperative to understand the nature and stability of the natural biological oceanic carbon sink.

Observing the Biological Carbon Pump The strength of the BCP has been estimated using a variety of techniques. These include sediment traps (analogous to rain gauges) which are moored in the deep ocean for periods of up to a year. They collect the sinking flux, segregating it into a series of samples so that the contributions of different organisms to flux, as well as the total flux, at different times can be investigated. Similar devices have been devised which drift in the surface ocean over shorter periods of time (few days) to sample the carbon flux in the top  500 m where it is changing rapidly (see Fig. 16.1). Other local estimates can be obtained from the uptake of new and regenerated nutrient species measured via the incorporation of tracers labelled with stable nitrogen isotopes. Larger-scale (in both space and time) estimates can be obtained from methodologies that include the deficits of naturally occurring radionuclides in the surface ocean or large-scale budgets of nutrient and CO2 concentrations. These various methodologies have not yet reached a consensus on the strength of the BCP, with plausible estimates of global export flux ranging from approximately 5–15 GT C year 1 (Henson et al. 2011). This lack of consensus on the strength of a major planetary carbon flux is of considerable concern and is stimulating much important research into understanding the underlying differences between estimates of BCP strength.

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Fig. 16.1 (Top) The decrease in sinking flux with depth estimated using the parameterization of Martin et al. (1987). (Bottom) Estimate of global carbon export (g C m 2 year 1) made using satellite-derived data (Redrawn from Henson et al. (2011))

Reduction of Sinking Carbon Flux with Depth As the sinking material descends in the water column, some of it is degraded and returned to the water via a complex series of microbially mediated reactions including ammonification, respiration, and nitrification. The depth at which this recycling occurs is critical to controlling the impact of the flux. If material is recycled deep in the ocean, then it will exchange with the atmosphere over much

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longer timescales (thousands of years) than if it is mineralized at shallow depths (tens of years). In addition, numerical models suggest that deep remineralization results in a larger oceanic storage of CO2 than shallow remineralization (Kwon et al. 2009). The depth of remineralization is hypothesized to be related to ecosystem structure, temperature, and oxygen concentrations. However, there are too few places where we have measured all these parameters simultaneously to attempt a robust analysis. The alternative strategy of producing a full mechanistic model is hampered by our inability to observationally close the mid-water carbon budget. In theory, the observed reduction in downward carbon flux should be exactly matched by measured heterotrophic activity over the same depth range. In practice such contemporaneous measurements are very difficult to make; however, the few that exist suggest a gross imbalance in the carbon budget with estimates of heterotrophy vastly exceeding the available supply of organic carbon (Burd et al. 2010). Such an imbalance clearly cannot be occurring, implying that our understanding of the remineralization processes in the mid-water region is rudimentary. Our understanding of what processes regulate mineralization depth is only qualitative at this stage, hampering our ability to model the sensitivity of atmospheric CO2 levels to changes in BCP functioning.

Controls on Carbon Sequestration in the Deep Ocean One factor which hinders the efficient export of material is that particles must be both dense and large to sink. Excess density is most easily acquired via the incorporation of ballast material (of either lithogenic or biogenic origin). Various types of phytoplankton contribute to the biological pump, including two particularly important classes of organisms which produce mineral exoskeletons. Diatoms produce the structural components of their cells from hydrated silicon dioxide (SiO2.nH20) and coccolithophores from calcium carbonate (CaCO3). However, these biominerals in themselves are not enough to allow particles to sink. Individual phytoplankton cells are so small (typically 50 % of exported biominerals reach the deep ocean)

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compared to the weak efficiency with which organic carbon is transferred (90 %), discontinuous (50–90 %), sporadic (10–50 %), and isolated (25  C, outcompeting most other

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groups of phytoplankton (Paerl and Huisman 2008). Currently, average water temperatures are only >25 in equatorial regions (ca. 10 m deep) usually thermally stratify in the summer. The duration and strength of thermal stratification can have profound influences on lake ecology. For example, cyanobacteria (also known as blue-green algae) are a common nuisance in some lake systems. When their populations increase, they may result in unsightly blooms with associated taste and odor problems. Furthermore, because many zooplankton avoid cyanobacteria as prey items, food webs change. Unfortunately for many cottagers, fishers, and lake managers, cyanobacteria can thrive in warmer waters and often are most competitive in well-stratified waters (Paerl and Huisman 2008), in addition to nutrient-rich waters. Similarly, longer periods of thermal stratification will result in more extended periods during which a lake’s deeper water layer (the hypolimnion) is isolated and may become depleted of dissolved oxygen. This can have serious repercussions on fish populations and other biota, potentially resulting in fish kills or compromised growth and development. Tropical lakes, although less well studied, are also closely linked to climate. Warming (and associated increases in thermal stratification) in some of the extremely deep rift lakes of Africa may actually result in decreased algal production. Verburg and Hecky (2009) showed that an increased thermal density gradient in Lake Tanganyika reduced the potential for vertical mixing of the water column and hence for the redistribution of algal nutrients. Consequently, primary production in the lake declined. Other lakes, due to increased evaporation, have declined in water levels and increased in salt content. Although the focus of this chapter thus far has been on low salinity lakes, inland saline lakes (also known as athalassic lakes) dominate in many regions of the world. Athalassic lakes are not connected to the sea but instead are closed-basin lakes (i.e., without an outlet) found in inland arid or semiarid regions. As such, they are highly influenced by changes in the relative proportions of evaporation to precipitation. If precipitation is high, so are water levels, and the lakes become diluted and

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HCO − 3 Ca 2+

CO 32−

CO 32− Ca 2+

Outflow

Cl − Na + Mg 2+

SO 24 − No outflow

Fig. 29.5 Schematic diagram showing some of the limnological responses of a closed-basin lake to changes in precipitation and evaporation. During wet periods (upper panel), lake levels are relatively high, and in some cases, the lake may have an outflow, and lakewater salinity is low. During periods of drought (lower panel), lake levels are lower and salinity increases, as evaporation exceeds precipitation. Typically, the longer the duration and severity of drought, the higher the salinity levels. Past salinity levels can be readily reconstructed using paleolimnological proxy indicators, such as diatoms (From Smol and Cumming (2000), with permission)

salinity decreases (Fig. 29.5). However, if evaporation exceeds precipitation, water levels decrease and the concentration of salts increases (in some lakes to several times the concentration of ocean water). Such lakes can record striking water chemistry changes during the course of a hot summer or interannual changes when one compares drought years to those with higher precipitation

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(Last and Ginn 2005). Because lakewater salinity is a key determinant of the distribution of aquatic organisms, it should be no surprise that saline lakes support different biotic communities to those found in other freshwater systems, and these assemblages can also be tracked in the paleolimnological record, from which past drought frequency and duration can be inferred. Similar to the research in polar regions, paleolimnologists have developed a wide spectrum of approaches to track long-term climate changes in temperate and tropical lakes. For example, the distribution of some invertebrates, such as various insect larvae (e.g., the Chironomidae or the nonbiting midges), appears to be especially sensitive to temperature changes. Chironomid taxa are well represented in the paleolimnological record by their chitinized head capsules (Fig. 29.2d). Different proxy indicators, such as diatoms, will thrive under particular climatic regimes, reflecting changes in ice cover, thermal stratification, water depth, and a spectrum of water chemistry variables that can be indirectly linked to climate change. For example, in athalassic lakes described above, diatom microfossils have become the main indicators used to track past lakewater salinity levels, from which the frequency and duration of past droughts can be reconstructed.

Conclusions Water quality and quantity are closely linked to climate. Not surprisingly, lakes are being increasingly referred to as “sentinels of climate change.” The fact that lake sediments often archive an important record of past ecological and other limnological changes that can be linked to climate makes paleolimnology an important tool for climate studies. Although some generalities can be made, lakes from different regions will respond to climate warming in a variety of ways. Our understanding of how lake ecology will change in response to climate warming is further complicated by associated shifts in precipitation patterns as well as a wide spectrum of other environmental changes. Moreover, due to the effects of other environmental stressors (e.g., acidification, eutrophication, and exotic species invasions), which may occur simultaneously with warming, the cumulative effects of multiple stressors are even harder to predict. What is clear is that climate can directly or indirectly affect a very wide spectrum of physical, chemical, and biological lake characteristics. Unfortunately, climate change is increasingly being shown to act as the “big threat multiplier,” often resulting in more serious ecological repercussions due to synergistic effects of land use and climate change. Given the importance of freshwater to human society and to biodiversity, these are not trivial issues and they warrant accelerated research.

References Cohen AS (2003) Paleolimnology: the history and evolution of lake systems. Oxford University Press, Oxford Last WM, Ginn FM (2005) Saline systems of the Great Plains of western Canada: an overview of the limnogeology and paleolimnology. Saline Systems 1:10. doi:10.1186/1746-1448-1-10

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Paerl HW, Huisman J (2008) Blooms like it hot. Science 320:57–58 Smith LC, Sheng Y, MacDonald GM, Hinzman LD (2005) Disappearing Arctic lakes. Science 308:1429 Smol JP (1988) Paleoclimate proxy data from freshwater arctic diatoms. Verhandlungen der Internationale Vereinigung von Limnologie 23(837):844 Smol JP, Cumming BF (2000) Tracking long-term changes in climate using algal indicators in lake sediments. J Phycol 36:986–1011 Smol JP, Douglas MSV (2007a) From controversy to consensus: making the case for recent climatic change in the Arctic using lake sediments. Front Ecol Environ 5:466–474 Smol JP, Douglas MSV (2007b) Crossing the final ecological threshold in high Arctic ponds. Proc Natl Acad Sci 104:12395–12397 Verberg P, Hecky RE (2009) The physics of the warming of Lake Tanganyika by climate change. Limnol Oceanogr 54(part 2):2418–2430

Additional Recommended Reading George G (ed) (2010) The impact of climate change on European lakes. Springer, Dordrecht, 507 pp Kernan M, Battarbee RW, Moss B (eds) (2010) Climate change impacts on freshwater ecosystems. Wiley-Blackwell, Oxford, 314 pp Smol JP (2008) Pollution of lakes and rivers: a paleoenvironmental perspective, 2nd edn. Wiley-Blackwell, Oxford, 383 pp

Threats to Freshwater Biodiversity in a Changing World

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David Dudgeon

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Freshwater Ecosystems: Scarcity, Richness, and Vulnerability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What Are the Threat Factors? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What Are the Global Patterns of Threat? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What Is Threatened? What Has Been Lost? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What of Climate Change and the Future? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What Now? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Keywords

Freshwater ecosystems • Scarcity, Richness and vulnerability • Threat factors • Global patterns of threat

Definition Fresh waters cover 18,000 species) of all vertebrates. Most of these (one quarter of all vertebrates) are fishes, and the rest comprise the entire global complement of crocodilians, virtually all of the amphibians, and most of the turtles. Considering just the bony (actinopterygian) fishes, species richness in the oceans and freshwater is similar (15,000 species each, with none in common) despite the greater productivity of marine environments. This remarkable richness is also disproportionate to the area occupied by freshwaters. The scarcity of fresh water has obvious and important implications for humans. A significant proportion of the global population (0.9 billion people) lacks ready access to drinking water, and perhaps 40 % (>2.5 billion) of people do not have adequate sanitation; child deaths resulting from contaminated water may be as high as 1.5 million annually – as many as 5,000 each day (WHO/UNICEF 2008). The demand for water has increased fourfold during the last 50 years, and the global population, which recently topped seven billion, is projected to reach nine billion by 2050 or thereabouts. Water for irrigation will be essential to feed these two billion additional people and improve the nutritional status of many others currently undernourished. Humans already appropriate 54 % of surface runoff and, although estimates of this proportion vary somewhat, increases in the foreseeable future could transgress planetary boundaries for

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sustainable water use (Rockstro¨m et al. 2009). While water-saving and irrigation technologies may slow the rate at which demand grows, the scope for further appropriation of water is limited as many rivers and lakes are situated in parts of the world (such as the far northern latitudes) where the inhospitable climate limits agricultural potential. The key point is that almost 10 % of global animal biodiversity is associated with fresh water covering less than 1 % of the Earth’s surface. This fact stands in stark juxtaposition to ever-growing human demand that results in consumption and contamination of the water which sustains that diversity. The vulnerability of freshwater to anthropogenic impacts is increased by the tendency for such impacts to be felt some distance away: for instance, changed land use within a drainage basin alters the timing, quantity, and composition of runoff, and the topographical position of rivers and lakes ensures that they are the eventual recipients of any and all material originating within their drainage basins. Furthermore, the unidirectional flow of rivers, together with the hierarchical arrangement of tributaries, means that impacts are not confined to one locality but transmitted downstream. Thus rivers are “receivers” and “transmitters” of contaminants and other materials, whereas lakes are “receivers” and may serve as sinks or “accumulators.” All freshwater are also “integrators” of the combined impacts of human activities within their drainages. To make matters worse, fresh waters are insular habitats – i.e., they are islands within a terrestrial matrix – and river drainages are isolated from each other by mountains or coastal waters that cannot be traversed by most freshwater animals. These barriers to dispersal limit the exchange of individuals or their genes, and the resulting isolation produces a considerable degree of local endemism: i.e., species become adapted to particular conditions within a lake or river, each of them having small geographic ranges relative to their terrestrial or marine counterparts. The outcome of insularity and endemism is high species turnover among lakes and river basins, accounting for the high richness (in per unit area terms) of freshwater animals. This turnover increases the vulnerability of freshwater animals to human impacts, because rivers and lakes (especially ancient lakes) tend to contain unique combinations of species that are not “substitutable,” and each drainage makes an irreplaceable contribution to the regional species total. Thus species loss from a single river or lake could represent global extinction. In combination, the scarcity of fresh water ensures that there is competition for water between humans and nature, while the insular nature and disproportionate richness of freshwater has the consequence that their degradation can lead to significant biodiversity losses. These losses are made more likely by the unique vulnerability of freshwater ecosystems since they serve as receivers, integrators, and sometimes transmitters of human impacts within their drainage basins. These three features collide within the “perfect storm” of human population growth and increasing water needs: as human requirements for water go up, that which remains for nature declines; the opposite does not apply.

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What Are the Threat Factors? The “perfect storm” is constituted by a number of separate but interacting elements: • Pollution of all types caused by inorganic or organic substances from point (e.g., end of pipe) or diffuse (overland runoff or seepage) sources, often comprising complex mixtures, with direct consequences ranging from lethal through acute to chronic (crossref. needed). Impacts can be indirect if pollutants reduce habitat suitability; for instance, soil runoff clogs riverbed sediments used by spawning fish. • Flow regulation used generally to encompass water abstraction for irrigation and other purposes; construction of large and small dams for water storage, flood control, or hydropower generation; long-distance transfers of water between drainages; and river channelization or canalization with associated dykes or levees that separate rivers from their flood plains. In extreme cases, a complex river corridor can be transformed into a massive, concreted drainage ditch. Dams and weirs are barriers to the movement of organisms and material within river networks, presenting a critical constraint for migratory fishes. Dams also degrade rivers by transforming the section upstream into an impoundment of standing water, while the flow downstream depends upon dam operations and may not resemble the original regime; sediment loads, oxygen content, and temperature of released water are likewise altered. Natural flow or inundation patterns – to which animals are adapted and upon which they depend – are modified, seasonal patterns of flow variability or water level fluctuations are reduced, and river dewatering or lake bed drying may even occur. • Overexploitation impacts animals used for food, mainly fishes but also frogs, some reptiles, and a few crustaceans and molluscs. Overfishing typically results from high catch effort, with larger, more long-lived species (often predators) tending to decline first, whereupon the fishery shifts to smaller, fecund species with short life cycles. Migratory species are particularly vulnerable, since they are often caught during movements that take place prior to breeding, so diminishing the capacity for stock replenishment. Declines also result from use of damaging fishing gear (fine-mesh nets, electrical devices, explosives, or poisons) often adopted as methods of last resort after larger fishes have been depleted. Crocodiles and turtles have been hunted, close to extinction in some cases, for their hides or other body parts, and unionid or “pearly” mussels in the United States were exploited for their pearls and nacreous shells (used to manufacture buttons) during the late nineteenth and early twentieth century; some species have yet to recover. • Drainage-basin alteration such as vegetation clearance affects the water balance within drainage basins and usually increases erosion. Changes in runoff quantity are accompanied by reduced quality (contaminants from farmland, towns, and cities) so degrading aquatic receivers. Clearance of riparian zones (along lake shores or river banks) and floodplains impacts semiaquatic animals (otters, herons, etc.) that live along water margins and amphibiotic species (frogs, dragonflies, etc.) that spend their adult phase on land.

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• Invasive species are nonnative to a particular region but have been introduced (accidentally or deliberately) by humans and become established. They are also known as introduced, exotic, or alien species, but the use of the term “invasive” denotes nonnative species that established themselves and spread at the expense of native species. Typically, invasives are effective competitors or efficient predators or possess an attribute lacking among members of the receiving community, but others cause damage by introducing parasites or diseases (including fungal chytridiomycosis that affects frogs). There is scant taxonomic constraint upon what makes a successful invasive. The category encompasses aquatic plants, snails, mussels, crayfish, mosquitoes, turtles, frogs, a few waterfowl, and many fishes (see the Global Invasive Species Database). The establishment of large, predatory Nile perch (Lates niloticus) – categorized among the 100 “World’s Worst” invaders – in Lake Victoria, East Africa, and the consequential disappearance of >200 species of endemic cichlid fishes, is but one example of the potential for damage. • Interactive effects among these five threat factors, and their multifarious components (including many not listed above), are pervasive since they can act simultaneously upon the same habitat. Indeed, the extent of drainage-basin alteration and pollution are often correlated. Habitat alteration may make animals more vulnerable to pollutants or, conversely, sublethal effects of contaminants may compromise their ability to adjust to changed conditions. New conditions may, in turn, facilitate establishment of invasives, and the greater the extent of habitat alteration, the less likely are native species to persist. In addition, pollution and habitat alteration limit the ability of fishes to withstand or recover from exploitation, and dams may prevent them for accessing breeding sites up- or downstream. In short, the five threat factors can combine to produce synergistic outcomes that can be difficult to predict and exceed the sum of their individual impacts.

What Are the Global Patterns of Threat? A recent global study of river health (Vo¨ro¨smarty et al. 2010) addressed the relative intensity of anthropogenic threats to both human water security and biodiversity. The two analyses each combined 23 weighted threat factors or stressors (termed “drivers”) within four categories: drainage-basin alteration, pollutants, water-resource development (i.e., dams and flow regulation), and biotic threats such as overfishing. However, the weighting applied to each driver varied between the two analyses, since their impacts differ greatly depending on whether they are felt by humans or (say) river fishes. For example, building a dam could be beneficial for human water security, whereas the effects on river fishes are negative. Conversely, mercury tends to accumulate along food chains posing a danger to apex consumers (crossref.); it is thus a greater threat to humans than to most fresh water organisms. Despite these separate driver weightings, low levels of water human security and high endangerment of biodiversity were generally

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correlated (Vo¨ro¨smarty et al. 2010). But, as Fig. 30.1 shows, the match between the two is not complete: there are places, mainly in Europe, North America, and Australia, where incident threats to human water security have been ameliorated by considerable investments in hard-path engineering and water treatment. There has been no comparable outlay to protect biodiversity, and thus conditions in such places are “good” for humans but “bad” for biodiversity. Elsewhere, and especially in densely populated parts of the developing world, the spatial pattern of threats to human water security and biodiversity is remarkably congruent: conditions are “bad” for humans and biodiversity (Fig. 30.1). Most notably, there seem to be no places where human water security is at risk in the absence of any threats to freshwater biodiversity, illustrating the tendency for human water requirements to take precedence over the needs of nature.

What Is Threatened? What Has Been Lost? While we cannot, yet, map the responses of freshwater biodiversity to variety of global-scale threats outlined above, we can nonetheless be confident about the extent and severity of changes that have already taken place (e.g., Dudgeon et al. 2006; Strayer and Dudgeon 2010). Given that human activities are already causing losses of marine and terrestrial species at least one to two orders of magnitude in excess of background extinction rates derived from the fossil record (Rockstro¨m et al. 2009), we must also have far exceeded whatever margins would have been sustainable for freshwater biodiversity. Population trend data consolidated in the Living Planet Index (WWF 2010) confirm this with steeper declines in animals living in fresh water than those on land or in the sea. Anadromous species, such as American shad (Alosa sapidissima) and Atlantic salmon (Salmo salar), that migrate between the sea and freshwater to breed have been especially hard hit, with declines in abundance of up to 95 % in rivers draining into the western Atlantic (Limburg and Waldman 2009). The IUCN Red List likewise reveals that a host of freshwater species is extinct or imperiled. For example, 38 % of freshwater fishes in Europe and 39 % in North America meet IUCN criteria for endangered-species status, incidentally underscoring the fact that securing human water needs by investments in river engineering and water treatment does nothing to relieve threats to freshwater biodiversity. Overexploitation and international trade of freshwater turtles due to their use in traditional Chinese medicine is reflected in the large number of species categorized as globally endangered. Inadequate knowledge of tropical freshwater biodiversity (Balian et al. 2008) adds some uncertainty over how much is being lost: while 31 % of 6,374 (mostly tropical) amphibian species are categorized as threatened by the IUCN, another 25 % of them are classified as data deficient (DD) because data on population trends are insufficient for a reliable conservation assessment. This pattern is more marked for Asian freshwater turtles: virtually all the non-endangered species are DD because they are rare, implying that they are already endangered. Data for most invertebrate taxa, as well as algae and microbes, are insufficient to determine global patterns of endangerment, but for some

Fig. 30.1 A global geography of river threat, showing the patterns of spatial concordance of aggregate threat from 23 drivers (see text) to human water security and freshwater biodiversity. Areas shaded gray have no appreciable river flow. Image from www.riverthreat.net

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groups (e.g., freshwater bivalves: 38 % classified as threatened by the IUCN) there are grounds for concern about species loss. Declines in freshwater species, including the first human-induced extinction of any species of cetacean (the Yangtze river dolphin, Lipotes vexillifer), are a reliable indicator of unsustainable use of freshwater by humans with consequences that have outpaced attempts at management (Dudgeon et al. 2006; Strayer and Dudgeon 2010). To this can be added a substantial extinction debt due to human actions that have reduced populations to levels from which they can no longer recover, as well as losses that occurred in the past that have been overlooked or forgotten. One example is the gradual disappearance, since medieval times, of beaver (Castor canadensis) from much of its former range in Europe. Another is American shad which supported a major commercial fishery along the western coast of the United States during the nineteenth century that has long since collapsed. Imperfect knowledge of past conditions in freshwater gives rise to “shifting baseline syndrome” whereby we are deceived by the false impression that conditions in the immediate past reflect conditions in the intermediate and distant past, so that we underestimate the extent of human impacts (Humphries and Winemiller 2009). The shifting baseline reduces expectations of what species should be present in freshwater, even in the case of economically important species, such as shad, soon after dams or other insults have eliminated them from particular rivers (Limburg and Waldman 2009).

What of Climate Change and the Future? Climate change was not included in the list of threat factors given above nor is it taken into account in the global river threat analysis shown in Fig. 30.1. Impacts on freshwater will arise from rising temperatures and alterations in rainfall and increased frequency of extreme climatic events, as well as medium-term effects such as glacial melt. There is already evidence of warmer water temperatures, shorter periods of ice cover, and shifts in the geographic ranges and seasonality of freshwater animals in northern latitudes (reviewed by Heino et al. 2009). Climate change does not augur well for freshwater biodiversity in regions where the human footprint is pervasive, since this is where conflicts over water will be most intense and the outlook for biodiversity correspondingly bleak. Warmer temperatures will mean greater water use by plants (crops, pasture, and natural vegetation), correspondingly less runoff or percolation to sustain rivers and lakes, and more water abstraction for irrigation. Changes in temperature and/or flow and inundation patterns could cause shifts in the timing of breeding or migration by fishes, and even the disappearance of seasonal cues for such life-cycle events. Consequences for reptiles, such as turtles and crocodiles in which the sex ratio is determined by temperature, could be extremely serious. Ultimately, conditions in rivers and lakes may no longer be suitable for species that evolved there, and there will be limited opportunities for overland dispersal by aquatic animals to more suitable habitat.

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An additional source of threat to freshwater biodiversity will originate from human adaptation to a more uncertain climate (increased floods and droughts), which is likely to stimulate dam construction for water storage, flood control and hydropower, and engineering work to mitigate potential water shortages or threats to human life and property arising from a more uncertain climate. These responses will magnify the direct impacts of climate change on biodiversity because they degrade freshwater ecosystems and limit their natural resilience. Furthermore, increased abstraction of water from lakes and rivers, combined with warmer temperatures, may increase the concentrations and toxicity of pollutants, interacting with existing uncertainty about the combined impacts of contaminant “cocktails” (crossref.). Climate change may also facilitate invasive species that threaten native biodiversity, through direct alterations in habitat conditions (warmer temperatures) or indirectly via construction of dams and impoundments where invasives can become established and spread to other locations.

What Now? With a few notable exceptions, freshwater biodiversity has – until recently – been largely overlooked by conservation scientists and the public, receiving only a fraction of the attention devoted to terrestrial or marine species. The result has been continued overexploitation of fish stocks and construction of dams that have altered habitats and access to breeding sites. Potential effects of pollution have received more attention, because of the direct implications for human health and water security, but drainage-basin alteration continues to be prevalent and rapid, while insufficient efforts are being made to address spread or impacts of invasive species. Thus, a first priority must be raising awareness of global declines in freshwater species and combining this with explanations of the value of this biodiversity to humans; demonstrations of the importance of well-managed inland fisheries would be a good place to start. Attention needs to be paid to restoring or rehabilitating habits and species in parts of the world where human water needs are relatively secure, but biodiversity remains under threat (Fig. 30.1), and action plans for management of critically endangered species need to be drawn up as a matter of urgency. The need to address water and sanitation needs of humans must take explicit account of concerns over biodiversity. Where trade-offs must be made, societal decisions should be taken with full knowledge that securing water for humans may be detrimental to biodiversity, rather than the prevailing approach where little or no account is taken of freshwater biodiversity and supporting ecosystems. There may be opportunities to meet human needs for clean water without resort to the plethora of hard-path engineering measures adopted widely in Europe and North America, thereby reducing impacts on biodiversity. Environmental water allocations for freshwater ecosystems (Poff et al. 2010), including controlled release of water from dams, is another measure that could be implemented. Finally, we need to facilitate the persistence of freshwater biodiversity in the context of a changing climate.

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If “stationarity is dead” (because climate change is altering means and extremes of temperature, rainfall, and river flow), then we must accept that conditions in lakes and rivers will alter more quickly than their inhabitants will be able to adapt to them. Given that dispersal opportunities to new habitats are constrained for most freshwater animals, can and should we consider their assisted translocation to potentially suitable sites (Olden et al. 2011) where their long-term persistence would be more likely? There is an urgent need to address all of these issues, if we are to avoid becoming overseers of more dramatic declines and extinctions of freshwater species than witnessed thus far.

References Balian EV, Le´veˆque C, Segers H, Martens K (2008) The freshwater animal diversity assessment: an overview of the results. Hydrobiologia 595:627–637 Dudgeon D, Arthington AH, Gessner MO, Kawabata Z-I, Knowler DJ, Le´veˆque C, Naiman RJ, Prieur-Richard A-H, Soto D, Stiassny MLJ, Sullivan CA (2006) Freshwater biodiversity: importance, threats, status and conservation challenges. Biol Rev 81:163–182 Heino J, Virkkala R, Toivonen H (2009) Climate change and freshwater biodiversity: detected patterns, future trends and adaptations in northern regions. Biol Rev 84:39–54 Humphries P, Winemiller KO (2009) Historical impacts on river fauna, shifting baselines and challenges for restoration. Bioscience 59:673–684 Limburg KE, Waldman JB (2009) Dramatic declines in North Atlantic diadromous fishes. Bioscience 59:955–965 Olden JD, Kennard M, Lawler JJ, Poff NL (2011) Challenges and opportunities in implementing managed relocation for conservation of freshwater species. Conserv Biol 25:40–47 Poff NL, Richter BD, Arthington AH, Bunn SE, Naiman RJ, Kendy E, Acreman M, Apse C, Bledsoe BP, Freeman M, Henriksen J, Jacobson RB, Kennen JG, Merritt DM, O’Keeffe JH, Olden JD, Rogers K, Tharme RE, Warner A (2010) The ecological limits of hydrologic alteration (ELOHA): a new framework for developing regional environmental flow standards. Freshw Biol 55:147–170 ˚ , Chapin FS III, Lambin E, Lenton TM, Scheffer M, Rockstro¨m J, Steffen W, Noone K, Persson A Folke C, Schellnhuber H, Nykvist B, De Wit CA, Hughes T, van der Leeuw S, Rodhe H, So¨rlin S, Snyder PK, Costanza R, Svedin U, Falkenmark M, Karlberg L, Corell RW, Fabry VJ, Hansen J, Walker BH, Liverman D, Richardson K, Crutzen P, Foley J (2009) Planetary boundaries: exploring the safe operating space for humanity. Ecol Soc 14:32, http://www. ecologyandsociety.org/vol14/iss2/art32 Strayer DL, Dudgeon D (2010) Freshwater biodiversity conservation: recent progress and future challenges. J North Am Benthol Soc 29:344–358, http://www.bioone.org/doi/abs/ 10.1899/08-171.1 Vo¨ro¨smarty C, McIntyre PB, Gessner MO, Dudgeon D, Prusevich A, Green P, Glidden S, Bunn SE, Sullivan CA, Reidy Liermann C, Davies PM (2010) Global threats to human water security and river biodiversity. Nature 467:555–561

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Additional Recommended Reading Global Invasive Species Database. http://www.issg.org/database/welcome/ IUCN Red List. www.iucnredlist.org Rivers in Crisis. Mapping dual threats to water security for biodiversity and humans. www. riverthreat.net WHO/UNICEF (2008) Progress on drinking water and sanitation: special focus on sanitation. World Health Organization and United Nations Children’s Fund Joint Monitoring Programme for Water Supply and Sanitation. UNICEF/WHO, New York/Geneva. http://www.who.int/ water_sanitation_health/monitoring/jmp2008/en/index.html WWF (2010) Living Planet Index 2010. World Wide Fund for Nature, Gland. http://assets.panda. org/downloads/lpr2010.pdf

Wetland Ecosystems and Global Change

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M. Siobhan Fennessy

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wetlands and Carbon Cycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Impact of Climate Change on Wetlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Keywords

Wetlands • Global climate change • Carbon cycle • Methane • Carbon dioxide

Definition The effects of global climate change will have serious consequences for wetland ecosystems, which store a substantial portion of the world’s carbon and so act to buffer the increasing concentrations of atmospheric carbon dioxide. Warmer and drier conditions may lead to increases in the flux of carbon from wetlands to the atmosphere, the loss of both inland and coastal wetlands, their biodiversity, and the provision of ecosystem services. Wetlands are shallowly to intermittently flooded lands where climate, landscape position, and the resulting hydrology affect both their structure (species composition and diversity, soil characteristics) and ecosystem function (productivity, nutrient cycling). They are called by names such as bogs and fens (peatlands

M.S. Fennessy Department of Biology, Kenyon College, Gambier, OH, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_129, # Springer Science+Business Media Dordrecht 2014

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found predominantly in high latitudes, between 50 N and 70 N) and marshes and swamps (dominated by herbaceous plants and trees, respectively, and found predominantly at lower latitudes). Estimates of the global extent of wetlands range from 5 % to 8 % of the Earth’s land surface, or 5.3 to 12.8 million km2, although approximately half of that area has been lost and much of the area that remains has become degraded due to human activities. The extensive loss of wetlands led to a recognition of the ecosystem services they provide, such as purifying and retaining water, cycling nutrients, sequestering carbon, and providing habitat for a high diversity of wetland-dependent species (Mitsch and Gosselink 2007). The predicted effects of global climate change on wetland ecosystems will be manifested in both direct and indirect ways and will depend on the types, magnitudes, and rates of change in temperature, precipitation, and runoff. Effects will arise directly through increasing temperatures, altered precipitation and hydrological regimes, and through rising sea levels that alter hydrology, biogeochemistry, and biomass production. Indirectly, the effects of other stressors on wetlands may be exacerbated by interactions with climate change, such as land use changes and upstream hydrologic impacts caused by groundwater withdrawals, agricultural drainage, and other human infrastructure.

Wetlands and Carbon Cycling Wetlands are important regulators of the global carbon cycle. While they cover only a small portion of the Earth’s land area, they contain an estimated 20–30 % of the Earth’s total soil carbon stores, or up to 700 Pg C (1015 g; Lal 2008). In total, the cumulative store of carbon in the world’s soils contains more carbon than the combined total amounts held in vegetation and the atmosphere. Two key processes in the carbon cycle that regulate the quantity of carbon in ecosystems are carbon fixation (i.e., photosynthesis) by plants, which removes CO2 from the atmosphere, and carbon release from the soil to the atmosphere (i.e., decomposition or respiration) (Fig. 31.1). Wetlands rank among the most productive ecosystems on Earth, so their capacity for carbon uptake is large. They also receive and release dissolved and particulate organic carbon (i.e., DOC and POC) through hydrologically driven inflows and outflows. Thus, the carbon pool within any wetland ecosystem is governed by the difference between net primary production, microbial decomposition in soils, and carbon fluxes in water with adjacent ecosystems (Fig. 31.1). In wetlands (including peatlands), waterlogging and anaerobic conditions slow the decomposition of organic matter and lead to its accumulation, thus they serve as a major reservoir of organic carbon and a sink of carbon from the atmosphere. However, wetlands also emit an estimated 115–227 Tg of methane (CH4) per year, or 20–25 % the total global methane emissions. Uncertainty about the balance between the sequestering of carbon in soils and the emissions of carbon as methane has led to some controversy (discussed below) about the ultimate role of wetlands in the global carbon budget. Do they ultimately serve as sinks or sources of greenhouse gasses?

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Atmospheric gases CO2

CO2 CH4

photosynthesis

respiration

CO2 CH4 Aboveground Primary Production

Carbon Inflow

Carbon Outflow

Belowground Primary Production

CO2 CH4

decomposition

Soil Organic Matter

Wetland Boundaries

Fig. 31.1 Conceptual model of the carbon cycle in wetlands showing the pathways of carbon flow between ecosystem components and the atmosphere

Impact of Climate Change on Wetlands Hydrology is a key driver of wetlands and has been called the “master variable” that determines ecosystem structure and function. Wetland hydrology describes the timing, duration, and frequency of inundation, and the resulting hydroperiod (the pattern of water levels over time) is one of the most important predictors, along with climate, of the type of wetland that will be present at a specific location. Wetlands are particularly vulnerable to the effects of global climate change due to their sensitivity to hydrological changes. As transition zones between aquatic and terrestrial environments, small changes in hydrology can drastically alter the extent, diversity, and function of wetlands. Small seasonal wetlands (those that are naturally dry for part of the year) are more likely to feel the effects of increasing temperatures that, in the absence of increasing precipitation, will lead to increased evaporation and transpiration (water transported through plants to the atmosphere, known collectively as evapotranspiration).

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Inland wetlands will be greatly affected by climate change from increasing temperatures and greater variability in precipitation. Altered precipitation can result in changing runoff amounts and alter groundwater inflows to wetlands (a major source of water supply for many sites). Even small changes in precipitation and evapotranspiration will be enough to alter the size of wetlands, shift species composition (e.g., shallower water levels may decrease the ability of some sites to support amphibian populations), or lead to a loss of wetlands from the landscape altogether as they are converted to uplands (Burkett and Kusler 2000). Wetlands that are the most susceptible to changes in precipitation and evapotranspiration occur in regions where the climate shifts from arid to mesic, such as North America’s Prairie Pothole Region (PPR). This region supports a high density of small wetlands (freshwater marshes) located in Minnesota and North and South Dakota in the USA and Manitoba, Saskatchewan, and Alberta in Canada, and supports 50–80 % of North America’s duck and other waterfowl populations. Climate predictions here indicate that drying conditions in the central and western sections of the PPR will diminish their extent, greatly compromising their habitat value. It may be necessary to undertake restoration programs for wetlands in the wetter, eastern portion of the PPR to compensate for these impacts on waterfowl populations (Johnson et al. 2005). Northern wetlands are particularly susceptible to changes as melting permafrost causes the loss of boreal peatlands (Junk et al. 2012). Boreal peatlands hold an estimated 20–35 % of the global total terrestrial carbon. In peatlands, drying and warming accelerate soil organic matter decomposition, which releases CO2 to the atmosphere, potentially making them a net source of C, and creating a positive feedback to global warming. In contrast, methane emissions may decrease if peatlands become drier, reducing waterlogging and the soil zones where methane is produced. Coastal and estuarine wetlands will be impacted by sea-level rise as a direct consequence of climate change, with sea levels expected to increase between 50 and 200 cm over the next century. A 100-cm rise would threaten an estimated 50 % of the wetlands designated as wetlands of international importance by the Ramsar Convention, the international treaty for wetland protection (Nicholls 2004). Coastal wetlands and mangroves that cannot transgress (i.e., migrate) inland to higher elevations, or accumulate organic matter and sediments at a rate to keep up with sea-level rise, will become increasingly inundated, leading to the dieback of vegetation and lower biomass production. Initially increased inundation may lead to greater methane emissions and carbon accumulation due to increased waterlogging and slowed decomposition. However, when the rate of vertical accretion of the marsh surface cannot keep pace with sea-level rise, marshes will become inundated and eventually disintigrate. Human land use changes, which have already led to the degradation of coastal wetlands, will also affect their ability to survive. In regions where coastlines have been developed, levees and dikes have been built to protect inland resources and have the effect of “squeezing” coastal wetlands, effectively trapping them between rising seas and the protected uplands

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Fig. 31.2 The global carbon budget showing the role of wetlands in carbon storage and emissions. Squares are stocks of carbon (Pg C) and arrows are fluxes (Pg C year 1) (From Mitsch and Gosselink 2007)

(Nicholls 2004). Ultimately these barriers to migration lead to marsh submergence and the complete loss of wetlands if vertical accretion cannot keep pace with higher seas. For the tidal freshwater systems that often lie on the landward edge of salt marshes, higher sea levels may lead to saltwater intrusion and the decline of their freshwater species. Many questions remain about how wetlands might mitigate (or contribute to) global warming as a function of carbon storage (sequestration) and the release of methane (Fig. 31.2). Higher CO2 levels in the atmosphere may lead to higher rates of photosynthesis and plant growth for many wetland plants. This increasing primary productivity has been termed the “fertilization effect” and will increase carbon sequestration if other factors are unchanged. Conversely, thawing permafrost and drying conditions due to higher temperatures and reduced surface and groundwater inflows can lead to peat oxidation (or in some cases, peat fires) and CO2 loss. Methane is of particular concern as a greenhouse gas because its radiative forcing (global warming potential or ability to trap heat) is about 25 times that of CO2. Wetlands are significant sources of methane; for instance, agricultural rice fields alone emit 60–80 Tg CH4 per year (nearly 10 % of all methane emissions) and more on an aerial basis than natural wetlands (Mitsch et al. 2012). Accounting for the estimated area of wetlands across all climatic zones (boreal regions, the tropics), a recent analysis of data on carbon sequestration and emissions indicates that wetlands are likely to be net carbon sinks on a global basis (Table 31.1).

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Table 31.1 Field estimates of carbon dioxide sequestration, methane emissions, and model results for a 100-year simulation of each wetland showing net annual carbon retention. These data drawn from Mitsch et al. (2012) showing a representative set of freshwater wetlands in tropical/subtropical, temperate, and boreal climates C sequestration Wetland type by (gCO2 m 2 year 1) climatic zone Tropical–subtropical Inland freshwater 154 delta Riverine 308 floodplain Forested slough 1,122 Temperate Freshwater 524 marsh Created 979 freshwater marsh Freshwater 2,024 marsh Boreal Peatland (tundra) 22a Peatland (tundra) 139 Peatland (fen) 552

Methane emissions (gCH4 m 2 year 1)

Ratio of CO2: CH4

Estimate of net C retention year (modeled)

96

1.6:1

42

350

1:1

84

44

26:1

306

76

7:1

143

63

16:1

267

64

32:1

504

16 8 73.6

1.4:1 17:1 7.5:1

6a 32 96

1

a

Indicates net CO2 release to the atmosphere

Globally, they retain up to 118 g C m 2 year 1, or about 830 Tg C per year. If correct, these estimates mean that the amount of carbon sequestered by wetlands is equivalent to about 12 % of the estimated carbon released each year from burning fossil fuels and is in the range of sequestration rates for terrestrial landscapes. Tropical and subtropical wetlands are particularly efficient at retaining carbon because of their high rates of biomass production. The recent interest in restoring or creating wetlands to compensate for the high rates of wetland losses may also help sequester carbon in soils; for example, restored wetlands in the PPR have the potential to retain 378 Tg of carbon over a 10-year period (Euliss et al. 2006). Wetland creation and restoration provide an opportunity to create carbon sinks and tackle climate change issues while positively addressing wetland habitat losses. Climate change is one of the most significant drivers of ecosystem change in the biosphere, and its effects will become more pronounced over time. A study of the ecological condition of the world’s ecosystems and the services they provide, the Millennium Ecosystem Assessment (MEA 2005), concluded that climate change can be “expected to exacerbate the loss and degradation of many wetlands and the loss or decline of their species.” The role of wetlands as carbon sinks makes them a key regulator of the global carbon cycle and a buffer to increasing concentrations of carbon dioxide. Programs to protect or restore them are vital.

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References Burkett V, Kusler J (2000) Climate change: potential impacts and interactions in wetlands of the United States. J Am Water Resour Assoc 36:313–320 Euliss NH, Gleason RA, Olness A, McDougal RL, Murkin HR, Robarts R, Bourbonniere RA, Warner BG (2006) North American prairie wetlands are important nonforested land-based carbon storage sites. Sci Total Environ 361:179–188 Johnson WC, Millett BV, Gilmanov T, Voldseth RA, Guntenspergen G, Naugle D (2005) Vulnerability of northern prairie wetlands to climate change. BioScience 55:863–872 Junk WJ, An S, Cı´zkova´ H, Finlayson CM, Gopal B, Kvet J, Mitchell SA, Mitsch WJ, Robarts RD (2012) Current state of knowledge regarding the world’s wetlands and their future under global climate change: a synthesis. Aquat Sci. doi:10.1007/s00027-012-0278-z Lal R (2008) Carbon sequestration. Philos Trans R Soc B 363:815–830 Millennium Ecosystem Assessment (MEA) (2005) Ecosystems and human well-being: wetlands and water synthesis. World Resources Institute, Washington, DC Mitsch WJ, Gosselink JG (2007) Wetlands, 4th edn. Wiley, Hoboken Mitsch WJ, Nahlik AM, Bernal B, Zhang L, Anderson CJ, Jørgensen SE, Mander U, Brix H (2012) Wetlands, carbon, and climate change. Landsc Ecol. doi:10.1007/s10980-012-9758-8 Nicholls RJ (2004) Coastal flooding and wetland loss in the 21st century: changes under the SRES climate and socio-economic scenarios. Glob Environ Chang 14:69–86

Additional Recommended Reading Bridgham SD, Megonigal JP, Keller JK, Bliss NB, Trettin C (2006) The carbon balance of North American wetlands. Wetlands 26:889–916

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Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ecosystem Goods and Services of Streams and Rivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Effects of Global Change on Ecosystem Goods and Services of Streams and Rivers . . . . . . . Cross-References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

The ecology of streams and rivers varies predictably from headwaters to mouth and regulates the ecosystem goods and services (EGS) of freshwaters and coastal zones of oceans. Headwater streams are particularly important in biogeochemical cycling and nutrient retention, whereas larger rivers are more important for fisheries support and water supply for drinking, irrigating crops, and industry. Increases in population density, urbanization, intensive agricultural, and migration of these activities to higher latitudes with climate change will greatly alter the complex interactions between the ecology of streams and rivers, the EGS they provide, and the human well-being that they support. Projected changes in water temperature, regional rainfall, storm intensity, and droughts with climate change increase threats to water supply and other EGS, which are already major problems today. Solutions to these problems can be initiated with known management strategies and refined with continued research on relationships among human activities, stressors, EGS, and human well-being.

R.J. Stevenson Department of Zoology, Center for Water Sciences, Michigan State University, East Lansing, MI, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_132, # Springer Science+Business Media Dordrecht 2014

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Keywords

Watersheds • Streams • Nutrients • Temperature • Rainfall • Ecosystem goods and services • Human well-being • Climate change • Land use change

Definition Climate and land use change will alter the ecology of streams and rivers, the ecosystem goods and services they provide, and the human well-being they support if management strategies are not initiated to control stressors from global change.

Ecosystem Goods and Services of Streams and Rivers Human activities reduce the ecosystem goods and services (EGS) provided by streams and rivers, with great variation related to global patterns in climate, climate change, geology, hydrology, culture, and economy (Bates et al. 2008). Streams and rivers provide water for drinking, irrigation, and industrial processes, fisheries, recreation, navigation, hydroelectric power, and support for biodiversity. Human alterations of temperature and weather by climate change as well as pollution and physical changes in watersheds will complexly affect EGS as a result of positive and negative interactive affects among these stressors, nonlinearities, feedbacks, and differing responses of EGS along gradients of human disturbance. The complexities of global change ecology are compounded by the great variation in linkages between ecological and social systems and natural differences among streams, rivers, and biogeoclimatic regions in which they occur (Smith et al. 2009; Stevenson 2011). Changes in rivers and streams resulting from global change were predicted more than a decade ago (Carpenter et al. 1992), and today, we have evidence that many of those predictions have started to occur. Streams and rivers are key routes for transportation and transformation of matter and energy across landscapes ranging from continents to small islands. Although streams and rivers contain a small proportion of all water on the planet (0.0002 %), most water, particularly freshwater, travels through streams and rivers on its way to lakes and coastal zones of oceans. The ecology of streams and rivers varies greatly and predictably from headwaters to mouths where rivers empty into the coastal zones of lakes and oceans. This predictable pattern has been called the river continuum (Fig. 32.1, Vannote et al. 1980) and holds for EGS as well as basic ecology of rivers and streams. Headwater streams are narrow channels that gradually widen as water accumulates within river basins and erodes a wider and wider channel. Most of the biological activity in streams is associated with the bottom, because they are shallow. When streams are very narrow and in biomes with forests, a tree canopy covers the stream to shade the bottom and restrain growth of algae on the stream bottom. But riparian trees deposit leaves into the stream to nourish the ecosystem. The leaves are shredded by aquatic insect larvae

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shredders grazers predators

microbes

1 collectors

trout

2

periphyton smallmouth bass

coarse particulate matter

collectors

microbes

fine particulate matter

3 vascular hydrophytes

shredders predators

grazers

Stream Size (order)

4

5

perch 6

periphyton

fine particulate matter

7

fine particulate matter

coarse particulate matter

8 phytoplankton 9 10 11

collectors

microbes

predators

catfish zooplankton

12 Relative Channel Width

Fig. 32.1 Illustration of the river continuum concept from Vannote et al. (1980) # 2008 Canadian Science Publishing or its licensors (Reproduced with permission and redrawn in FISRWG (1998))

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into smaller and smaller pieces which become small enough that they easily float downstream. This fine particulate organic matter is filtered from the water by aquatic insect larvae using fan-shaped appendages or nets spun with secretions. Other aquatic insect larvae swim across deposits of fine sediments and consume them with appendages modified to collect particles from the stream bottom. Bacteria and fungi (decomposers) coat this coarse and fine particulate organic material, decompose the more labile parts, and also harvest organic molecules and inorganic nutrients that are dissolved in the water to further nourish the aquatic insect larvae that were either shredding, filtering, or collecting the organic matter that originated outside the stream channel. In wider streams, when the tree canopy cannot shade the bottom, or narrower streams in deserts, grasslands, or alpine biomes without trees, algae grow prolifically across the stream bottom. These “benthic” algae absorb inorganic nutrients from the water and photosynthesize to enable their prolific growth. Benthic algae are consumed by grazing insect larvae and snails, nourish bacteria and fungi, and then drift downstream to be captured by the filter-feeding aquatic insect larvae or collected from the bottom after settling in slow current areas called pools. As streams aggregate, they form rivers that are sufficiently deep and usually sufficiently turbid that light does not reach the bottom. Algae mostly grow in the water column in rivers, so they are called phytoplankton; but benthic algae are also on the bottom in the shallow margins of rivers. In rivers, the benthic filter-feeders, collectors, and grazers continue to function across all or part of the river, and an additional group of small, largely neutrally buoyant animals, the zooplankton, accumulate and consume suspended algae and bacteria. In addition, another diverse group of aquatic invertebrates, the mussels, can develop in abundance and filter algae and organic matter from the water column of rivers. During low flow periods when water flows slowly and resides in the river for longer periods of time than high flows, phytoplankton and zooplankton can accumulate to high abundances, like those that would be observed in lakes. Groundwater is a huge reservoir of freshwater, 0.75 % of all water and 30 % of all freshwater. The exchange of groundwater and surface water in streams is little appreciated. Water in streams originates from precipitation that either runs off the surface of the land or penetrates soils and discharges into streams from shallow or deep groundwater sources. The route of precipitation to the stream varies with porosity of soils. In sandy soils, large portions of precipitation percolates to deeper groundwater storage zones so that storms have relatively little effect of river discharge compared to shallow soils over bedrock and steep slopes, where runoff from the land surface causes great storm surges and floods. During low flow periods between storms, most water in streams and rivers originates from groundwater, and during this time, substantial proportions of water move between the ground and surface water zones. The biodiversity and ecosystem processes of streams and rivers extend into gravels and sands below the bottom of the channel as a result of this exchange of groundwater and surface water, and sometimes to great depths depending upon porosity of the channel bottom. The zone below the stream bottom is called the hyporheos. It contains a great abundance of bacteria, fungi, and aquatic insect

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larvae. Recharge of groundwater from streams carries dissolved and particulate organic matter that nourishes the bacteria, fungi, and aquatic insect larvae that live in the hyporheos. There bacteria and fungi decompose organic matter and release inorganic nutrients. Evidence of decomposition in hyporheic zones can be seen on the downstream side of gravel bars where algae sometimes grow prolifically in the nutrient-rich groundwater that leaks back into the stream channel. Decomposition of dissolved and particulate organic matter by bacteria and fungi, uptake of inorganic nutrients by decomposers and algae, and the filtering, collecting, and grazing of bacteria and fungi by aquatic insect larvae contribute to biogeochemical cycling and nutrient retention, which are major ecosystem services of streams and rivers. The organisms of streams transform and retain matter and energy within the river ecosystem in a process called spiraling, in which matter and energy cycles from stream bottom to water column and consequently flows downstream (Webster and Patten 1979). Consumption of decomposers, algae, and invertebrates by fish also helps retain matter in streams and rivers. Aquatic insect larvae emerge from streams as adults, fly upstream more than downstream, and many are consumed by birds, spiders, and other terrestrial predators. Floods scour organic matter (living and dead) from streams and deposit them in the flood plain. Headwater streams are particularly important in transformation and retention of nutrients and organic matter leaking from the landscape, because the volume of water in them is relatively small compared to the surface area of the channel. Photosynthesis by algae and decomposers’ utilization of terrestrial and aquatic sources of organic matter fuel stream and river ecosystems. Primary production, biogeochemical cycling, and nutrient retention are examples of intermediate EGS that regulate water quality and provide clean water for drinking, industrial and agricultural processes, and recreation. Some of the most fertile soils for agriculture are floodplains of rivers where organic matter from streams and rivers was deposited during floods. The in-stream processing of both nutrients and terrestrial inputs of organic matter prevents their transport to coastal zones where they could feed algal blooms. Fisheries of streams and rivers are also nourished by the food webs based on algal production and decomposers using terrestrial inputs. In many parts of the world, small fishes as well as large fishes are harvested for local consumption or support of local businesses that ship them far away. Thus, streams and rivers provide a diversity of intermediate services that have in-stream, floodplain, and downstream benefits, which lead to many final ecosystem services that provide direct benefits to humans (Boyd and Banzhaf 2007), such as drinking water, industrial and agricultural water supply, recreation, fisheries, biodiversity, and food crops.

Effects of Global Change on Ecosystem Goods and Services of Streams and Rivers Climate change and human alterations of the surrounding landscapes will have complex independent and interactive effects on the EGS of streams and rivers. To resolve this complexity, it helps to consider the direct and indirect effects of global

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change on streams and rivers and then consider them independently and interactively. Human alterations have affected streams and rivers for millennia, but today, these alterations are globally distributed. Agriculture, urban development, and roads alter the physical and chemical structures of landscapes. They increase runoff, alter flashiness of stream hydrology, and increase erosion across the landscape and in the stream channel. They pollute streams with sediments, pesticides, toxic chemicals from industrial wastes, and nitrogen and phosphorus from fertilizers and wastes of humans and animals. Climate change will increase stream temperatures and the frequency of heavy rains and droughts. Heavy rains will exacerbate the problem with runoff of nutrients and sediments from the landscape and channel erosion during high flow events. Sediment pollution reduces water clarity and habitat suitability for the bacteria, algae, and invertebrates and limits their contributions to EGS. Many stream bottoms have cobble, gravel, or sandy bottoms to which biota have adapted. Fine sediments from erosion bury these habitats and the microbes on them. Excess sediments on the stream bottom prevent growth of algae and bacteria; they alter motility and food sources for aquatic invertebrates as well. Sediments in the water column shade the bottom and clog the filter-feeding of aquatic insects. Thus, sediment pollution reduces the retention capacity of streams. Sediments then decrease biogeochemical cycling as well as productivity of the food web. Nutrient pollution increases algal growth and overwhelms the capacity of the stream to retain nutrients. Increased growth of algae can alter biodiversity in streams by physically altering habitat structure in ways that affect which aquatic insects can live in the habitat. Algal photosynthesis during the day releases oxygen into the water. Algal and bacterial respiration uses the dissolved oxygen in the water. This produces diurnal fluctuations in dissolved oxygen with daytime highs and nighttime lows. Excessive algal growth also supports more bacteria in streams. As algae and bacteria accumulate, the fluctuations increase sufficiently that nighttime dissolved oxygen gets so low that many organisms, particularly fish and aquatic insect larvae, cannot survive. Human activities have heavily altered the natural flow regimes of rivers with dams, groundwater withdrawals, stream channel dredging, groundwater withdrawals, and impervious surfaces. These flow alterations profoundly alter biodiversity and ecosystem functions (Poff and Zimmerman 2010; Sabater 2008). Channels of streams and rivers are carved by the power of water moving through them, so changes in the frequency and intensity of high and low flow events alter physical structure and resulting chemical and biological conditions. Increased impervious surfaces (roads, roofs, parking lots) increase the rate at which rain reaches streams; this increases peak flood flows that cause greater bank erosion and sediment deposition in channels. Dams are constructed for hydropower and water storage providing irrigation, drinking water, and flood control, but they threaten biodiversity by blocking migration of fish to upstream habitats which are commonly breeding habitat. Groundwater withdrawals for irrigation, hydrologic fracturing, and drinking water supply can deplete surface water flows, habitat area, and stream temperature by changing groundwater:surfacewater ratios in channels. Dredging

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stream channels reduces habitat diversity, reduces flow resistance in channels, and increases downstream flooding. Headwater streams have been buried and channelized with agricultural and urban development, which reduces or eliminates their capacity for waste uptake and retention. Reduced flood flows in channels below dams allow sediments to accumulate long enough that trees and shrubs encroach on channels as they spread across gravel bars. So, human alterations of stream and river hydrology complexly affect EGS, increasing some and decreasing others. Increases in air temperature will increase water temperature, which affects dissolved oxygen and the kinds of organisms that can live in the streams. Kaushal et al. (2010) show that stream temperatures across North America have increased by 0.009–0.077  C year 1 with the greatest increases in urban areas. The capacity for water to hold dissolved oxygen decreases as water temperatures rise, such that 100 % saturation of water with dissolved oxygen will decrease about 1 ppm with a 4  C increase in water temperature. In addition, metabolism of organisms tends to increase with temperature across most ranges of temperatures in streams, so metabolic demand for oxygen will increase and the capacity of water to hold oxygen will decrease with global warming, which will further exacerbate low oxygen problems. Low dissolved oxygen is one of the major threats to biodiversity and ecosystem functioning in rivers and streams. Temperatures have strong direct effects on the species of aquatic insects, fish, and algae that can live in streams. In general, metabolism of organisms increases with temperature until it reaches an optimum, above which temperature reduces efficiency of metabolic processes. Thus, species have an optimum temperature range with upper and lower tolerances to changes in temperature. One of the major effects of global warming on final ecosystem services will be transformation of trout fisheries into warm water fish habitat. For example, Hari et al. (2006) found that brown trout populations have already started to decline in alpine rivers of Europe. Climate change will also have profound effects on water delivery to rivers and streams. Regional variations in warming will affect precipitation and flow in rivers and stream such that precipitation and flow will increase in some regions and decrease in others. Changes in precipitation by climate models can simulate observed patterns in long-term stream flow (Milly et al. 2005). When models of future climate change and streamflow are linked, they indicate 10–40 % decreases in rivers in western North America, northern and southwestern South America, western and southern Africa, southern Europe, the Middle East, and Western Asia (Fig. 32.2). They also predict 10–40 % increases in flows in northern North American, Europe, and Asia, northwestern and southeastern South America, north central and eastern Africa, and southern Asia. Lehner et al. (2006) used an integrated water model called WaterGAP to simulate high and low flow conditions under future climate change scenarios. They determined that events with an intensity of today’s 100-year frequency of occurrence would occur as often as 10–50 years by the 2070s. In addition, global warming is melting glaciers and snowpacks, which strain water supply during the summer when it is most needed for drinking and crop irrigation. Stewart et al. (2004) estimated peak runoff in snowmelt-dominated systems, like mountain streams, will occur 30–40 days earlier than today.

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Fig. 32.2 Mean relative percentage change in flows predicted for the twenty-first century (Milly et al. 2005)

Thus, many areas will be threatened with increased flooding as others are threatened by increased droughts and water scarcity. Palmer et al. (2008) estimate that 13 % of the world’s large river basin area, 7 % of the entire world’s area when summed, will suffer from water scarcity, and nearly one billion people live in those areas. Problems with water scarcity may be exacerbated by vulnerability to decreases in water quality and other EGS. Increases in flood intensity and drought duration in combination with global warming could cause greater problems with algal blooms and threats to drinking water supply (Paerl and Huisman 2008). Nutrient runoff with floods is expected to increase with expected storm intensity with global warming. When droughts follow floods during warm periods of the year, water retention time in rivers should increase and enable greater algal blooms. In combination with flood flows introducing nutrient loading, increased water retention time with droughts should provide a longer time for algae to accumulate, sequester available nutrients, and cause problems with low oxygen, biodiversity, and drinking water supplies. Stable water column conditions can occur in large rivers at low flow which favors accumulation of cyanobacteria, which can produce toxins. Algal blooms also affect drinking water by causing taste and odor problems and by producing precursors for toxic chemicals, such as trihalomethanes that develop during disinfection of drinking water. Climate change will drive land use changes as agriculture moves to higher latitudes where climate will be sufficiently warm to grow crops. Population density, nutrient loading, and accompanying diverse demands and threats to streams and rivers will move with agriculture. Many areas today are suffering great losses in agricultural sustainability as ground waters are extracted for irrigation faster than they can be replenished. As these areas are further degraded, demand for other marginal lands will increase. Thus, new regions will be altered as agriculture migrates toward higher latitudes, new rivers and streams will be exposed to the stressors of agriculture and accompanying urban development, and abandoned landscapes and water resources will remain scarred and require long periods for recovery.

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When threats to EGS such as water quantity, quantity, and biodiversity are combined, nearly 80 % of the world’s population is exposed to problems of water security and biodiversity (Vo¨ro¨smarty et al. 2000). Solutions to problems exist, but mitigation of impacts and adaptation to water demands by agriculture and growing urban populations require great investments in infrastructure, which leaves many poorer societies vulnerable (Vo¨ro¨smarty et al. 2010). Ecosystem restoration costs much more than stressor management before impacts have occurred. Management will be challenged, because real tradeoffs exist in managing in-stream conditions and watersheds. Some alterations of ecosystems, such as dams and aquaculture, increase services provided by rivers for irrigation and food production, but negatively affect other in-stream and downstream uses. Prioritizing management of pollution, biological invasions, dams and river fragmentation to protect EGS will require rigorous quantitative understanding of relationships among them and spatial optimization in ways that protect critical EGS in locations where they remain and restore them in locations most in need or requiring the least investment. Future climate and land use change will complicate management, which increases the need to act now.

Cross-References ▶ Impacts of Projected Changes in Climate on Hydrology ▶ Precipitation Regimes and Climate Change ▶ Threats to Freshwater Biodiversity in a Changing World

References Bates BC, Kundzewicz ZW, Wu S, Palutikof JP (eds) (2008) Climate change and water: technical paper of the intergovernmental panel on climate change. IPCC Secretariat, Geneva Boyd J, Banzhaf S (2007) What are ecosystems services? The need for standardized environmental accounting units. Ecol Econ 63:616–626 Carpenter SR, Fisher SG, Grimm NB, Kitchell JF (1992) Global change and fresh-water ecosystems. Annu Rev Ecol Syst 23:119–139 FISRWG. (1998) Stream Corridor Restoration: Principles, Processes, and Practices. Federal Interagency Stream Restoration Working Group. 15 Federal Agencies of the United States Government, Washington, D.C. Hari RE, Livingstone DM, Siber R, Burkardt-Holm P, G€ uttinger H (2006) Consequences of climatic change for water temperature and brown trout populations in Alpine rivers and streams. Glob Chang Biol 12:10–26 Kaushal SS, Likens GE, Jaworski NA, Pace ML, Sides AM, Seekell D, Belt KT, Secor DH, Wingate RL (2010) Rising stream and river temperatures in the United States. Front Ecol Environ 8:461–466 Lehner B, Do¨ll P, Alcamo J, Henrichs T, Kaspar F (2006) Estimating the impact of global change on flood and drought risks in Europe: a continental, integrated analysis. Clim Change 75:273–299 Milly PCD, Dunne KA, Vecchia AV (2005) Global patterns of trends in streamflow and water availability in a changing climate. Nature 438:347–350 Paerl HW, Huisman J (2008) Blooms like it hot. Science 320:57–58

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Palmer MA, Liermann CAR, Nilsson C, Florke M, Alcamo J, Lake PS, Bond N (2008) Climate change and the world’s river basins: anticipating management options. Front Ecol Environ 6:81–89 Poff NL, Zimmerman JKH (2010) Ecological responses to altered flow regimes: a literature review to inform environmental flows science and management. Freshwater Biol 55:194–205 Sabater S (2008) Alterations of the global water cycle and their effects on river structure, function, and services. Freshwater Rev 1:75–88 Smith MD, Knapp AK, Collins SL (2009) A framework for assessing ecosystem dynamics in response to chronic resource alterations induced by global change. Ecology 90:3279–3289 Stevenson RJ (2011) A revised framework for coupled human and natural systems, propagating thresholds, and managing environmental problems. Phys Chem Earth 36:342–351 Stewart IT, Cayan DR, Dettinger MD (2004) Changes in snowmelt runoff timing in western North American under a ‘business as usual’ climate change scenario. Clim Change 62:217–232 Vannote RL, Minshall GW, Cummins KW, Sedell JR, Cushing CE (1980) The river continuum concept. Can J Fish Aquat Sci 37:130–137 Vo¨ro¨smarty CJ, Green P, Salisbury J, Lammers RB (2000) Global water resources: vulnerability from climate change and population growth. Science 289:284–288 Vo¨ro¨smarty CJ, McIntyre PB, Gessner MO, Dudgeon D, Prusevich A, Green P, Glidden S, Bunn SE, Sullivan CA, Liermann CR, Davies PM (2010) Global threats to human water security and river biodiversity. Nature 467:555–561 Webster JR, Patten BC (1979) Effects of watershed perturbation on stream potassium and calcium dynamics. Ecol Monogr 19:51–72

Additional Recommended Reading Allan JD, Castillo MM (2007) Stream ecology: structure and function of running waters, 2nd edn. Springer, New York National Research Council (2008) Ecological impacts of climate change. National Academy Press, Washington Stevenson RJ, Sabater S (2010) Understanding effects of global change on river ecosystems: science to support policy in a changing world. Hydrobiologia 657:3–18

Lake Nutrients, Eutrophication, and Climate Change

33

John Jones and Michael T. Brett

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lake Nutrients and Eutrophication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Keywords

Eutrophication • Lakes • Nutrients • Nitrogen • Phosphorus • Trophic state • Carbon • Cyanobacteria

Definition Research suggests the problems of nutrient over-enrichment (eutrophication) and climatic warming are coalescing in lakes globally. This oftentimes leads to cyanobacteria dominance of lake algal communities, which is problematic because cyanobacteria can produce toxins, degrade beneficial and aesthetic properties of lake water, and impede fisheries production. Cyanobacteria are prevalent when lakes have high nutrients (especially phosphorus) and high water temperatures. Currently, industrialized animal production is a locally important source of

J. Jones (*) Department of Fisheries and Wildlife Sciences, University of Missouri, Columbia, MO, USA e-mail: [email protected] M.T. Brett Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_109, # Springer Science+Business Media Dordrecht 2014

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excess nutrients. Various means have been employed to alleviate the negative consequences of eutrophication and cyanobacteria blooms, with controls on external nutrient inputs being the most effective. More aggressive nutrient control programs will be called for in the future just to hold pace with the steadily declining water quality in many lakes.

Lake Nutrients and Eutrophication Nutrient enrichment of lakes from human activity is known as cultural eutrophication; this worldwide problem is typically manifested as a dramatic increase in the density of algal cells suspended in water (Smith and Schindler 2009). In extreme cases algae detract from human uses of water and reduce the natural diversity of aquatic communities. Eutrophication is costly to society. Concern about changes in lake water quality intensified in the 1960s following the widespread use of phosphorus in household detergents, sharp increases in the application of nitrogen fertilizer to boost crop production, and localized waste disposal from “industrialized” animal production (Schindler and Vallentyne 2008). The human eye can easily detect the green hue of lakes that have been enriched with algae. Consequently even the general public can visually assess the status of individual lakes and detect changes over time. The green color becomes apparent as lakes switch from moderate to increased fertility at about 10 parts per billion of the photosynthetic pigment, chlorophyll. Over the past four decades, fundamental research has characterized the eutrophication processes and informed lake restoration programs (Cooke et al. 2005). Initially phosphorus was identified as the most important nutrient-limiting algal biomass of lake waters. This conclusion was based on the nitrogen-phosphorus (N:P) ratios found in algal cells relative to concentrations in natural waters and the results of numerous nutrient addition experiments, conducted in enclosures and whole lakes, showing phosphorus amendments stimulated algal growth. The geochemistry of phosphorus also suggests it should be more limiting; it has no gas phase and readily binds with iron, aluminum, and carbonates and subsequently becomes buried in the sediments. Phosphorus limitation is also linked with high atmospheric nitrogen deposition and agricultural runoff; both sources can supply nitrogen in excess thereby enhancing phosphorus limitation. Research has shown carbon, an element that accounts for about half the mass of algal cells, is readily available from inorganic sources such as bicarbonates dissolved in lake water, and carbon dioxide from the atmosphere and organic matter decomposition. Carbon can limit algal growth rates in the short term but does not limit biomass in the long term. Phytoplankton nitrogen deficiency has also been identified using N:P ratios in lake water and algal growth responses to nutrient addition bioassays. N-limitation is more common than previously thought and is detected routinely. It is often found in productive lakes, lakes in regions were atmospheric nitrogen deposition is low and lakes in arid or tropical/subtropical regions. Initially the gas phase of nitrogen

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was considered to be an available nutrient pool that could be used by N-fixing cyanobacteria to alleviate nitrogen shortfalls and maintain lakes in a state of P-deficiency. In productive lakes, N-fixers are common, but numerous studies show nutrient limitation in moderately productive lakes is often balanced, resulting in temporal shifts between nitrogen and phosphorus limitation. The factors contributing to nitrogen limitation include high inputs of phosphorus from anthropogenic sources of domestic and animal wastes (characterized by low N:P ratios), geologic sources of P, temporal differences in the competitive abilities of phytoplankton to use plant nutrients, and sediment release of phosphorus to lake water concurrent with losses of nitrogen via denitrification (anoxic release of N2 back to the atmosphere). There is no simple explanation for why N-fixers do not consistently satisfy nitrogen deficiencies, and the importance of nitrogen limitation remains a key research question. Studies in a variety of lake types subsequently showed that lake total phosphorus concentrations (TP) are a function of external inputs from watersheds, lake hydraulic residence time, and the tendency of the phosphorus to settle from the water column (Brett and Benjamin 2008). Release of phosphorus from lake sediments (internal loading) during anoxic periods can also be a critical component of the phosphorus cycle. Nitrogen models are more complex because they must account for the flux of the gas phase in and out of lakes as N-fixation and denitrification, respectively. Regardless, inflow concentration is a critical factor in determining lake water concentrations for both nutrients. Collectively, models show increased inputs from anthropogenic sources such as municipal sewage, agricultural crops and manures, and non-point sources from developed watersheds, such as lawn fertilization, promote eutrophication. As a consequence, there is very large variation in the nutrient content of lakes due to the intensity of anthropogenic activities (e.g., agriculture and urban areas) within their watersheds. Usually deep lakes with low human activity and intact vegetation in the watershed are less eutrophic than shallow lakes with large, disturbed watersheds. Plant nutrients are considered “causal variables” because the undesired consequences of eutrophication can be attributed to their concentrations in lake water. The response of lakes to nutrient inputs is often demonstrated with cross-system comparisons showing patterns across a broad range of lake types. The underlying assumption is that the response in an individual lake can be predicted by the overall pattern shown for many lakes. The patterns between causal and response variables are strong enough to stand out among other sources of variation. The empirical relationship between total phosphorus (TP) and algal chlorophyll (Chl, a surrogate for algal biomass, Fig. 33.1a) shows the pattern of increased algal biomass with lake water nutrients and provides a framework for predicting the outcome of nutrient controls (N€ urnberg 1996). There is large variation in the Chl:TP ratio in individual samples; low ratios can be attributed to processes that secondarily reduce cell density; including light limitation from mineral turbidity and seasonal deep mixing, limitation by other nutrients, and rapid flushing such that algal cells cannot take complete advantage of available nutrients. Also, intense algal grazing by filter feeders (zooplankton or mussels) can outpace algal production and result in low

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Fig. 33.1 Panel (a) – algal biomass measured as chlorophyll pigment (parts per billion, ppb) from Missouri reservoirs sampled in summer 2005 plotted against the total phosphorus concentration (ppb) in the same sample (axes were transformed using log base 10). Panel (b) – secchi transparency as a measure of water clarity (meters) in Missouri reservoirs sampled in summer 2005 plotted against the corresponding chlorophyll value (from Panel a) showing the hyperbolic relationship between the two variables. Panel (c) – a hypothetical representation of the established relationship between deep-water oxygen consumption in lakes (hypolimnetic oxygen demand, mg/m2/day) and total phosphorus concentrations. The equation for oxygen demand and total phosphorus is from N€urnberg (1996), and data are from Missouri reservoirs in summer 2005

cell densities (Cooke et al. 2005). High Chl:TP ratios (near the top of the distribution, Fig. 33.1a) represent periods when algal growth is not strongly constrained by physical factors or intense grazing. In these samples algal density reaches the potential set by nutrients, and maximum Chl:TP ratios are about four times the long-term average. Maximum algal densities are rare but suggest nuisance conditions occasionally occur in otherwise aesthetically pleasing, relatively clear-water lakes (Jones et al. 2011). In contrast, these same concentrations are a common feature of nutrient-rich lakes. For example, Chl values of 10 ppb, where algae are visually noticeable, are uncommon when TP is 50 ppb TP (Fig. 33.2a). Nuisance conditions are associated with Chl >30 ppb; but these conditions are rare in lakes with 1,000 tons per year (Hunt et al. 2010). All the applications mentioned above require a high level of purity of CO2 to avoid contaminations and side reactions. Therefore, a purification step would be required for the utilization of CO2 originating from flue gas or from the atmosphere. Currently, fermentation provides CO2 of high purity for these applications. Interestingly, CO2 can be recovered and reused in each example. CO2 is already widely used for its physical properties across different industries. Hence, the amount of CO2 used in this sector is likely to remain in the same range. However, the use of scCO2 as a solvent is currently growing for ecological and economical reasons and also because of a better efficiency in certain types of chemical reactions.

Biological Valorization Conversion of carbon dioxide into biomass is an appealing opportunity compared to other mitigation options as it uses rather inexpensive components. However, the light efficiency of superior plants and algae is low (1.5–2.3 % and 4.5–6 %, respectively), and large amounts of cultures are required to reach high capture rates (Aresta 1999; Wang et al. 2008). For instance, a 400 km2 forest is necessary to compensate the emissions of a 500 MW plant (Aresta 1999) and 1.5 km2 open bond for a 150 MW plant. Microalgae are able to fix carbon dioxide through three different sources, which includes atmosphere, flue gas, or soluble carbonates (Wang et al. 2008). Fixation of CO2 from soluble carbonates is an advantageous opportunity as it allows to store CO2 during the night as carbonates which can be

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processed during the day. Furthermore, only few species survive in saline and highpH environment, which makes the culture easy to control. However, microalgae are usually cultivated in ponds or closed systems exposed to air which contains 0.03–0.06 % CO2. The two main strategies in biomass mitigation are to use biomass for fuel or chemical productions and to store CO2 in biomass. Bio-mitigation to produce chemicals or fuels consists mainly in growing algae in a CO2-rich environment. After harvesting, the biomass is dried and treated before conversion to afford chemicals or fuels. Harvesting and conversion are the most expensive steps of this procedure because of the low cell density (0.3–0.5 g/L) and the energy required in the conversion step. Biofuels are currently 2.3 times more expensive to produce than fossil fuels and 90 % of the cost of biodiesel is due to harvesting, drying, and lipid extraction. The overall cost is thus comparable to other mitigation methods, and all these extra-operations go against the common belief that biomass are zero emission fuels. Therefore, it is necessary to design reactors that allow maximum light penetration and a higher cell density. The second strategy is to store carbon in materials for at least 50–200 years to have a sufficient impact on the reduction of greenhouse gases. The demand for wood products is proportional to the population and will therefore rise with increasing population. Wood used for housing and construction is expected to store 3–8 times more carbon than steal or concrete products (Petersen et al. 2005). Therefore, it appears that biomass has a better potential in storing carbon in durable building materials than in energy production. However, a better understanding of the life and carbon cycles and storage is needed to allow optimal usage of this mitigation method. Polymers made from natural renewable resources are an interesting alternative. These biopolymers are often biodegradable and nontoxic and can be directly extracted from the biological system or synthesized from naturally occurring monomers by chemical synthesis or biotechnology methods. Their properties and resistance depend on the copolymer composition and can be adjusted. Biodegradable biopolymers degrade under certain conditions and after a certain amount of time to form water and CO2 or small molecules. Polyglycolic acid (PGA) possessed similar properties to PET and is commercialized by Dupont and applications include plastic bags, thermoformed bottles, and eating utensils (Flieger et al. 2003). The applications of polylactic acid (PLA) are broad given that it can be used in biomedical engineering, packaging (film, bags, thermoformed containers), clothing, and to make outdoor furniture (Flieger et al. 2003). The biodegradable thermoplastic poly (e-caprolactone) (PCL) has a short degradation time and is therefore used in biomedical applications such as bone fixing or in composite for regulation of drug release. Polyhydroxyalkanoates (PHA) have a wide range of applications in the industry (surface coating, everyday articles, and instruments), agriculture (controlled release of insecticides and mulch films), medicine (surgery materials and cardiovascular implants), and nanocomposites (Flieger et al. 2003). These polymers are made from renewable sources and offer an interesting alternative to fossil fuel-derived plastics used for everyday materials such as plastic bottles or packaging. However, in most cases the crude biomass cannot be used, and fermentation is required to obtain the starting block or the polymer, which

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produces CO2. Moreover, the polymers degrade after a certain time either to form water and CO2 or small molecules. Therefore, the overall balance of the process needs to be closely studied to make sure it results in a favorable outcome. Recently, nondegradable biopolymers such as polythioesters were reported and may find applications for durable material. The biological use of CO2 may highly increase given that biomass is receiving large attention for the production of biofuels. However, the biological valorization of CO2 needs to address several concerns regarding the usage of other resources such as water and metals if metalloenzymes are involved. In addition, the conversion of biomass into chemicals is expensive. Therefore, it is likely that genetic engineering will allow to elaborate high-yielding strains which are able to produce a specific chemical under harsh conditions.

Chemical Valorization Chemistry offers several possibilities to valorize CO2 given that it can be reacted in different types of reaction, and the carbon content of biomass compared to chemicals is in average 51 mol% C versus 65 mol% C (Petersen et al. 2005). Moreover, the algal biomass possesses an average energy content of 18–21 kJ/mol (23–29 kJ/mol under optimized conditions) (Hunt et al. 2010) that is half of that diesel fuel (43 kJ/mol). Chemicals are therefore more efficient in storing carbon and energy than biomass, and this approach is among the most promising leads to valorize CO2. Carbon dioxide can react to form C–C, C–N, or C–O bonds. However, there are only a few industrialized processes that use CO2. Therefore there is a huge potential to create new processes, new products with new properties. Adapting existing synthesis to use CO2 is the first step. For instance, polycarbonates are mainly synthesized using phosgene, and only ca. 15 % of the worldwide total production are synthesized using CO2. Therefore, replacing phosgene by CO2 would allow to increase the amount of carbon dioxide used while reducing both health and environmental risks. In addition, only three or four polycarbonates have been studied extensively. Therefore, there is a huge potential to develop new polymers by changing either the monomer or by alternating building blocks during the synthesis. This would allow to generate new materials the property of which would need to be studied. Similarly, polyurethanes, which have a broad range of applications, can be synthesized starting from CO2 (Aresta and Dibenedetto 2007). Recent progresses in the preparation of acrylic acids and derivatives, which are used in the fabrication of polymers, coatings, adhesives, polishes, and paints from carbon dioxide, are encouraging, and it is reasonable to envisage their preparation from CO2 (Mikkelsen et al. 2010). Alternative synthetic routes using CO2 towards other chemicals should be investigated next which may lead to the discovery of new compounds. Cyclic carbonates are an interesting class of compounds and are prepared directly from CO2 (He et al. 2009). These molecules were found to be efficient fuel additives, and there consumption is expected to reach several megatons in the future. These compounds are also used as solvent for batteries.

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The other main valorization pathway is the reduction of CO2. Carbon monoxide has been used for many decades in the Fischer-Tropsch process to yield alkanes and fuels (Khodakov et al. 2007). Therefore, utilization of CO in this well-known process is a major opportunity, and the focus should be set on finding an efficient and renewable method to afford hydrogen which is expensive and required to produce CO. The interest for formic acid has been growing over the last years because of its potential use as a hydrogen-storing chemical (Enthaler 2008). Hydrogenation of carbon dioxide affords formic acid (HCOOH) which can be stored as a liquid. Decomposition of formic acid using an iron catalyst yields CO2 and H2 which can be used readily (Federsel et al. 2010). Ideally, a close system can be imagined where CO2 is recycled for further storage and hydrogen is recovered from the water formed during H2 combustion. Many progresses have been made in thermochemical, photochemical, and electrochemical processes (Mikkelsen et al. 2010). However, the material cost and the degradation of the material is a major concern and improvements are still required for large-scale applications.

Conclusion In summary, there is no miracle solution to the CO2 issue, and it is a combination of techniques that will allow reducing both the emissions and the concentration in the atmosphere. CCS, air capture, and CO2 valorization combined together offer an interesting strategy to create value from an environmental issue. Moreover, this consists a challenging and exciting research frame where innovation and discoveries that have a direct impact on everyday life can be made. Acknowledgments Prof. Dr. Dominique Bourg and Prof. Dr. Suren Erkman from UNIL are gratefully acknowledged for insightful discussion.

References Aresta M (1999) Perspectives in the use of carbon dioxide. Quimica Nova 22:269–272 Aresta M, Dibenedetto A (2007) Utilisation of CO2 as a chemical feedstock: opportunities and challenges. Dalton Trans 28:2975–2992 D’Alessandro DM, Smit B, Long JR (2010) Carbon dioxide capture: prospects for new materials. Angew Chem Int Ed 49(35):6058–6082 Enthaler S (2008) Carbon dioxide – the hydrogen-storage material of the future? ChemSusChem 1(10):801–804 Federsel C et al (2010) A well-defined iron catalyst for the reduction of bicarbonates and carbon dioxide to formates, alkyl formates, and formamides. Angew Chem Int Ed 49(50):9777–9780 Flieger M et al (2003) Biodegradable plastics from renewable sources. Folia Microbiol 48(1):27–44 Haszeldine RS (2009) Carbon capture and storage: how green can black be? Science 325(5948):1647–1652

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He LN, Wang JQ, Wang JL (2009) Carbon dioxide chemistry: examples and challenges in chemical utilization of carbon dioxide. Pure Appl Chem 81(11):2069–2080 Hunt AJ et al (2010) Generation, capture, and utilization of industrial carbon dioxide. ChemSusChem 3(3):306–322 Keith D, Ha-Duong M, Stolaroff J (2006) Climate strategy with CO2 capture from the air. Clim Change 74(1):17–45 Khodakov AY, Chu W, Fongarland P (2007) Advances in the development of novel cobalt Fischer-Tropsch catalysts for synthesis of long-chain hydrocarbons and clean fuels. Chem Rev (Washington, DC, United States) 107(5):1692–1744 Lackner KS (2010) Washing carbon out of the air. Sci Am 302(6):66–71 MacDowell N et al (2010) An overview of CO2 capture technologies. Energy Environ Sci 3(11):1645–1669 Mikkelsen M, Jorgensen M, Krebs FC (2010) The teraton challenge. A review of fixation and transformation of carbon dioxide. Energy Environ Sci 3(1):43–81 Petersen G et al (2005) Nongovernmental valorization of carbon dioxide. Sci Total Environ 338(3):159–182 Wang B et al (2008) CO2 bio-mitigation using microalgae. Appl Microbiol Biotechnol 79(5):707–718

Population Growth and Global Change

65

Bill Freedman

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Human Population and Global Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Growth of the Human Population . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Increases of Mutualistic and Synanthropic Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Per-Capita Environmental Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cross-References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

There has been enormous growth in the human population, from 1 to 10 million about 10,000 years ago to more than 7 billion in 2013. There have also been huge increases in the populations of species living in close association with humans. Just as important, history has witnessed a great intensification of per-capita environmental effects related to the use of natural resources, the generation of wastes, and damage caused to biodiversity. The multiplicative consequences of population size and per-capita effects are captured by indicators such as ecological footprints, thereby allowing the notion of overpopulation to be applicable to both less-developed and wealthier countries. Because of its enormous size, the global population is at risk of suffering a large and rapid “crash” as a consequence of environmental damage that has decreased carrying capacity for the human economy, or by a global pandemic caused by an emergent disease. Human overpopulation and the environmental and ecological damages that it causes provide the essential context for the study of all anthropogenic global changes.

B. Freedman Department of Biology, Dalhousie University, Halifax, NS, Canada e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_39, # Springer Science+Business Media Dordrecht 2014

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Keywords

Human population • Domesticated species (mutualists) • Synanthropic species • Overpopulation • Carrying capacity • Ecological footprint

Definition The global environmental consequences of the human population have increased enormously as a result of huge increases in both the numbers of people and in the intensity of their per-capita use of resources, generation of wastes, and appropriation of space.

The Human Population and Global Change Environmental conditions have changed throughout the history of life on Earth. Some of these changes have been catastrophic in terms of their consequences for the biota and ecosystems that existed at the time. The most cataclysmic examples are the mass-extinction events that mark the passage of geological eras, such as that occurring about 65 million years ago at the end of the Cretaceous and apparently caused by massive environmental damage following a large meteorite strike in the vicinity of what is now Yucatan in Mexico. However, those early environmental disasters were all caused by natural agencies. In contrast, the so-called “modern environmental crisis” is essentially anthropogenic in its causation, resulting from environmental and ecological changes that are associated with the rapid growth of industrialization, urbanization, and other manifestations of an increasingly burgeoning human population and economy. These changes have grave consequences for the sustainability of the human economy itself and also for the prospects of the longer-term viability of natural ecosystems and much of the world’s biodiversity. In essence, the rapid economic growth of recent centuries is due to large increases with regard to two main factors: (1) the populations of humans and associated species and (2) an intensification of per-capita environmental damages, which is particularly great in wealthier countries. These two factors are discrete considerations with respect to environmental damages associated with global change, but they are also inseparable because of their intrinsic association. Both are considered here because they provide essential context for all anthropogenic global changes.

Growth of the Human Population Populations of any species, including those of humans, change because of variations in the relative rates of four demographic variables: the birth rate, death rate, immigration rate, and emigration rate. The rate of population change is calculated

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Table 65.1 An outline of the population history of Homo sapiens. Data are from Freedman (2010) and World Resources Institute (2011)

Time 8000 BCE 0 CE 1650 1850 1930 1975 2000 2013

573 Population (106) 1–10 300 500 1,000 2,000 4,076 6,124 7.1

Doubling time (year) 1,500 – 200 80 45 36 55 59

as DP ¼ BR + IR  DR  ER. However, for a global or otherwise closed population, the equation is DP ¼ BR  DR, also known as the “natural” rate of change. In studies of human populations, the rates are typically standardized to units of per thousand, such as 15 births/1,000 people. The abundance of humans has increased tremendously over the past several thousands of years. It is likely that during the first 95 % of the approximately 200-thousand year history of Homo sapiens, our global population was some 1–10 million individuals. This “natural” baseline abundance began to grow as human cultural evolution discovered new and improved ways of harvesting and utilizing natural resources. Among the earliest important discoveries were the domestications of fire and of the dog and the discovery of better tools for hunting and processing foods and materials. These and other cumulative improvements of lifestyle and economy all effectively raised the carrying capacity of exploited ecosystems for the human enterprise, allowing populations to slowly grow. About 10,000 years ago, the earliest agricultural practices began to widely take hold and to become progressively improved, including the cultivation and domestication of crop plants and the husbandry of animals. This first agricultural “revolution” led to more rapid population increases than had previously occurred, as have subsequent and cumulative discoveries related to foods, materials, medicines, technology, sanitation, sources of energy, social organization, information handling, and other qualities of an increasingly sophisticated global human civilization. Collectively, these cumulative and progressively adaptive changes might be referred to as “human socio-technological evolution.” A rough outline of the population history of humans is provided in Table 65.1. From a historical preagricultural baseline of 1–10 million, the population increased slowly but steadily to about 300 million at 0 AD, reached 0.5 billion in 1650, and then one billion in 1850. The growth rates then markedly increased, largely because of large reductions of death rates due to improvements in sanitation and medicine, so that the next doubling to two billion took only 80 years, and the subsequent one to four billion only 45 years. The fastest growth rates occurred in the late 1960s and early 1970s, when they were about 2.1 % per year, but they have subsequently slowed, to about 1.1 %/year in 2013 (when this article was written). The slowing is due to progressive reductions in birth rates towards the lower parameters earlier attained by death rates, as the global population makes progress

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through its demographic transition. This is the change in demographic parameters from an initial “primitive” condition in which high birth rates are balanced by high death rates (both typically 40–45/1,000), so there is approximately zero population growth (ZPG), to a “modern” state of ZPG with low birth and death rates (both 9–12/1,000). Historically, as human populations have moved through their demographic transition, the death rate has typically fallen much more quickly than the birth rate, so that there was a rapid increase in the population size. Demographic transitions can be studied in any defined group of people, ranging from cultural groups to countries to the global population. Despite the recent slowing of growth rates in recent years, the human population is now extremely large, and the absolute amount of increase remained strong at about 70 million per year during 2002–2013. Medium-level projections are that the global population may increase to about nine billion by 2050, when it may level off to a no-growth condition.

Increases of Mutualistic and Synanthropic Species It is also useful to consider the recent abundances of other large animals that have benefited from living in a mutualistic relationship with the human economy, in the sense of both parties having reciprocal benefits with respect to factors affecting their population sizes (Freedman 2010). The most abundant of these mutualists are sheep and goats (Ovis aries and Capra hircus), which now have a combined abundance of about 1.9 billion individuals, while there are 1.4 billion cows (Bos taurus and B. indica) and 1.0 billion pigs (Sus scrofa). Among smaller mutualistic animals, there are about 17 billion domestic fowl alive in any year, mostly chickens (Gallus gallus), and there may be 400 million dogs (Canis lupus familiaris) and more than 500 million cats (Felis catus). Some other wild animals and plants also maintain relatively large populations because they live in a synanthropic relationship with humans, in which they receive habitat benefits but are not used by people as an important resource. Some of the most abundant synanthropes are alien pests such as the black rat (Rattus rattus), rock pigeon (Columba livia), and dandelion (Taraxacum officinale). None of these or other mutualistic and synanthropic species would be able to maintain their unnaturally large abundances if it were not for favorable habitat conditions created deliberately or inadvertently by humans. As such, their large populations might be considered as being both a component and a consequence of the environmental impact of the human population. Remarkably, the enormous populations of modern humans and some associated species may represent the largest abundances every attained by a large animal (i.e., weighing more than about 44 kg or 100 lb). For comparison, the most populous large wild animals for which reasonably accurate population estimates are available are the pre-exploitation stocks of American bison

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(Bison bison) at about 60–80 million individuals and recent populations of whitetailed deer (Odocoileus virginianus) in the Americas at 40–60 million, large kangaroos (Macropus giganteus and M. rufus) in Australia at 57 million, and crabeater seal (Lobodon carcinophagus) of the Southern Ocean at 15–30 million. The abundances of these large wild animals are only about 1 % or less than that of modern humans, which provides a context for deliberation upon the size of the population of Homo sapiens.

Per-Capita Environmental Effects It is important to recognize that the environmental consequences of any human population are a result of both: (1) its absolute size, as well as (2) its per-capita rates of resource use, generation of wastes, and despoliation of natural habitats. As such, any judgment of overpopulation, or of an ecological footprint, must take both of these vital considerations into account. This important point was first noted by an English clergyman, Thomas Malthus, in his highly influential An Essay on the Principle of Population, first published in 1798. In essence, Malthus noted that human populations of the time were increasing at an exponential rate, but the food supply only at an arithmetic rate. Because of this large apparent disparity, Malthus predicted that overpopulation would soon lead to mass starvation. As it turned out, the human population has grown far beyond what Malthus would have imagined to be sustainable. This occurred without causing a population crash because of tremendous advances that have been made in sanitation, medicine, food production, and in technology more generally. Nevertheless, the predictions of Malthus are still considered to be generally realistic, in the sense that the human population cannot keep growing forever. One of the first indicators to be widely used to examine the environmental impacts of human populations was the IPAT equation, in which environmental impact (I) is the multiplication of population size (P) x affluence (A) x technology (T). In this sense, “affluence” is related to the per-capita rate of consumption of goods and services in an economy, and “technology” accounts for environmental damages associated with their means of production (including resource depletion, pollution, and risks to biodiversity). The importance of accounting for both the population size and per-capita effects is clear from the review of environmental indicators for a selection of countries in Table 65.2, which compares their national and per-capita use of energy, gross domestic product, and ecological footprints. Energy use and GDP are presented as simple environmental indicators, based on the reasonable assumption that larger values suggest proportionately more consumption of resources, generation of wastes, and appropriation of space. The ecological footprint is a more complex indicator. It attempts to account for the areas of major habitats (e.g., cropland, fisheries, forest, urbanized areas) that are required to produce the

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Table 65.2 Simple indicators of the relative environmental impacts of selected countries. Population data are for 2011; energy use is for 2005 in tonnes of oil equivalent (TOE); gross domestic product (GDP) is for 2006 in current US dollars; ecological footprint is for 2010. Data are from Global Footprint Network (2011) and World Resources Institute (2011)

Population Country (106)

Gross domestic Energy use product Ecological footprint Per-capita National Per-capita National Per-capita National (TOE) (106 TOE) (US$) (109 US$) (ha) (106 ha)

Biocapacity (106 ha)

China India Canada USA

1.32 0.49 8.47 7.89

1,337 583 490 1,205

1,359 1,237 34.0 318

1,717 537 274 2,342

$2,002 $792 $39,033 $43,468

$2,645 $912 $1,272 $13,164

2.21 0.91 7.01 8.00

2,941 1,048 230 2,472

bioresources needed to support the economy of a country. This “footprint” is compared with the available areas of those habitats, which is referred to as the “biocapacity.” China and India are the most populous countries in the world, each supporting about five times as many people as the United States and 39 times as many as Canada. However, the per-capita intensities of energy use in Canada and the USA are much larger than in China (averaging 6.2 times greater) or India (17 times), so that national energy consumption in the USA is the largest in the world, and that of Canada is within an order of magnitude (factor of 10) of those of China and India. Similarly, the per-capita GDP of the USA and Canada both average about 30 times larger than that of China or India, but the national GDP of the USA is 7.4 times greater than the average of China and India, while Canada is comparable to those much more populous countries. The comparisons of ecological footprints are even more telling. The USA and Canada have much larger per-capita footprints than do citizens of China or India, averaging about five times larger. This is a result of the relatively intensive lifestyle of wealthier people in terms of their use of resources, production of wastes, and appropriation of land. On a national basis, however, the footprints of China, India, and the USA are of a comparable magnitude, while that of Canada is about 11 % that of those much more populous countries. It is important to note, however, that China, India, and the USA are all substantially exceeding the estimated biocapacities of their national territories, by an average of two times, suggesting that their economies are grossly non-sustainable. In comparison, Canada is a large country with a moderate-sized population, and it has a footprint that is about one-half of its biocapacity. At a global scale, the footprint data suggest that the average human footprint (2.7 ha/person) is about 1.5 times larger than the available biocapacity of the biosphere (1.8 ha/person). Broad conclusions that might be developed from comparisons of these population-level and per-capita indicators are that China, India, the USA, and the world are all overpopulated. Canada may not yet be in that condition, although its population grew at about 1 % per year during 2002–2011, so in less than four decades, even that spacious country would be considered overpopulated according to these environmental indicators.

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Conclusions The human population has grown enormously from its “natural” abundance of 1–10 million prior to the first developments of agricultural enterprise about 10,000 years ago to about more than 7 billion in 2013. There have also been enormous increases in the abundances of various mutualistic and synanthropic species that live in close association with people. Moreover, during the course of human socio-technological evolution, there has been a cumulative intensification of per-capita environmental effects, which are characterized by large increases in per-capita resource use, generation of wastes, and appropriation of space. Because ecological footprints are a multiplicative product of population size and per-capita effects, the notion of overpopulation is applicable to both less-developed and wealthier countries. In this sense, many developed countries should be viewed as being overpopulated, in addition to many less-developed ones, and indeed the global human population. Because of its enormous size, the global population is at risk of suffering a large and rapid “crash.” This would most likely be caused either by environmental damage that has resulted in a large decrease in carrying capacity for the human economy or by a global pandemic due to an emergent disease afflicting large and densely living populations with little immunity. Human overpopulation and the resulting environmental and ecological damages provide an essential context for all anthropogenic global changes.

Cross-References ▶ Population Policies

References Freedman B (2010) Environmental science. A Canadian perspective, 5th edn. Pearson Canada, Toronto Global Footprint Network (2011) Ecological footprint and biocapacity, 2007. Oakland. http:// www.footprintnetwork.org/en/index.php/GFN/ World Resources Institute (2011) EarthTrends. The environmental information portal. WRI, Washington, DC. http://earthtrends.wri.org/index.php

Additional Recommended Reading Ehrlich PR, Ehrlich AH (1990) The population explosion. Simon & Schuster, New York Pearce F (2010) The coming population crash: and our planet’s surprising future. Beacon Press, Boston Wackernagel M, Rees WE (1996) Our ecological footprint: reducing human impact on the earth. New Society Press, Gabriola Island Weeks JR (2008) Population: an introduction to concepts and issues, 10th edn. Thomson Wadsworth Publishers, Florence

Population Policies

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Roderick J. Lawrence

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Population Growth and Demographic Transition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rationale of Population Policies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Controlling Fertility and Natality Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . United Nations Population Conferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Contemporary Policies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

580 580 580 581 581 582 583 583 583

Abstract

Population policies are meant to regulate changes to human populations in defined areas or localities (cities, countries, etc.) These policies commonly consider altering the birthrates by measures that can either increase or decrease fertility rates. Other policies can target migration flows by measures that can increase or decrease immigration (arrivals of foreigners) or emigration (departures of residents). Population policies that control growth rates are usually implemented by a political authority. These policies are often in conformity with religious dogma, cultural values, and political ideals. Keywords

Demographic transition • Fertility rates • Migration flows • Natality rate • Population control

R.J. Lawrence Institute for Environmental Sciences, University of Geneva, Carouge, Switzerland e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_92, # Springer Science+Business Media Dordrecht 2014

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Definition Population refers to a group of human beings. Population policies are meant to regulate changes to human populations in defined areas or localities. The growth of human populations is a major factor for environmental change in the world with direct consequences for impacts on uses of natural resources and production of wastes. At both the global level and regional levels, demographic trends will influence the course of change of natural ecosystems, the local economy, geopolitical relations, and quality of life.

Introduction The acceleration of population growth since the early eighteenth century can be summarized by the following data. In the early 1800s, during the first phase of industrialization, the world population was about one billion. A century later, in about 1930, the world population reached two billion. The United Nations Population Fund estimated that the world population had reached five billion in 1990, then it increased to six billion in October 1999 and then to seven billion in 2012. Some have characterized this exponential growth rate as a “population explosion.” This has been attributed to numerous factors including increased agricultural productivity coupled with improved distribution of food; greater access to education, medical, and health care; and improved housing, living, and working conditions especially in urban areas.

Population Growth and Demographic Transition The acceleration of population growth during the last two centuries has been related to what has been termed “the demographic transition.” This concept is based on an interpretation of demographic history developed in 1929 by the American demographer Warren Thompson (1887–1973). Demographic transition refers in the first instance to declining mortality rates which meant that people began to live longer; life expectancy has doubled in many so-called developed countries since 1900. In addition, the demographic transition refers to declining fertility rates in these same countries during the last half of the twentieth century. Birthrates and death rates vary between countries, and different ethnic groups in a specific country, owing to different cultural, economic, and political circumstances which vary over historical periods. The growth of a human population in a specific area or country is the sum of the number of live births and deaths which is referred to as the natural population size of that locality at a precise time. This number is supplemented by the sum of the number of persons migrating into and leaving the area at the same time. Human population control is the explicit alteration of these two demographic trends (Demeny and McNicoll 1998).

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Rationale of Population Policies Population policies are meant to regulate changes to human populations in precise localities (cities, countries, etc.) These policies commonly consider altering the birthrates by measures that can either increase or decrease fertility rates. Other policies can target migration flows by measures that can increase or decrease immigration (arrivals of foreigners) or emigration (departures of residents). Population policies can aim to increase or decrease population growth for various reasons; for example, lower population growth rates may be intended owing to reduced access to food, water, energy sources, housing, or employment. On the contrary, higher population growth rates may be intended to complement other policies or programs that promote economic and industrial development or the decentralization of economic activity or a public administration. Australia and Canada are two countries that have explicitly introduced financial incentives to attract immigrants to their countries especially after 1945. Migration flows between countries and regions of the world are explicitly controlled by sovereign states, which claim the right and possess to a certain degree of control, to regulate the movement of people across national boundaries. The right to move from one country to another is proclaimed in the Universal Declaration of Human Rights. In practice, however, this right has not been respected by many nondemocratic regimes (e.g., countries of the former Soviet Union and Yugoslavia). Moreover, many countries with a democracy (including those in the European Union and Switzerland do not respect freedom of entry to foreigners. Population policies that control growth rates are usually implemented by a political authority. These policies are often in conformity with religious dogma, cultural values, and political ideals. Historically, those measures that can be applied to regulate natural population growth (not migration flows) include the practice of abstinence, contraception, abortion, infanticide, sterilization, euthanasia, and genocide.

Controlling Fertility and Natality Rates The regulation of birthrates can involve measures that improve people’s lives, especially women during the childbearing period of their life cycle, by enabling them to have a degree of personal control over their reproduction. However, there are recorded cases of political authorities that have severely imposed population control such that women have no choice in the number of children they can have. Historically, population control was advocated by Thomas Malthus in An Essay on the Principle of Population as it Affects the Future Improvement of Society first published in 1798. His contribution has had a wide influence on many contemporary authors who have supported stringent controls on population growth. Malthus argued that if population growth, which increases in a geometric ratio, was not controlled, then famine would result because food subsistence only increases in an arithmetic ration. Malthus also stated that there is a practical limit to the amount of

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food that can be produced. Hence, a maximum number of people can be fed. If the population increases above this number then, owing to starvation, the death rate will rise to equal the birthrate. Malthus also noted that “positive checks” such as infectious diseases, droughts, and warfare increased the death rate, whereas “preventive checks” including moral restraint, abstinence, and birth control measures influence the birthrate. Malthus wrote that the poor were most affected by access to subsistence and, consequently, they should be educated to apply “preventive checks” to lower population growth Ehrlich and Holdren (1971). Since the 1960s and 1970s, a population control movement has been active. During this period there have been many alarmist predictions about the exponential growth of the world population. Paul R. Ehrlich, for example, published The Population Bomb in 1968. He advocated population policies including compulsory birth control using sterilizers added to food and drinking water. In 1990, Ehrlich repeated his viewpoint in another book titled The Population Explosion which he coauthored with his wife. Like Ehrlich some authors repeatedly claim that overpopulation is the cause of poverty, high unemployment, environmental degradation, famine, and genocide. Some advocates of population control have related their concerns to the concept of finite carrying capacity. Others state that unequal demographic growth between regions and countries can influence geopolitics, but there is no empirical evidence to support this claim.

United Nations Population Conferences The First World Population Conference was organized by the United Nations, and it was held in Rome from 31st August to 10th September 1954. This academic conference debated how to measure the characteristics of populations and study those variables that influence these characteristics. The Second World Population Conference was organized by the United Nations and the international Union for the Scientific Study of population (IUSSP). It was held from 30th August to 10th September 1965 in Belgrade. The conference linked fertility rates to policies for development planning at the time when scientists debated the negative impacts of exponential population growth. The Third World Population Conference was organized by the United Nations, and it was held in Bucharest from 19th August to 30th September 1974. The aim of this event was to seek political support for lower population growth rates by the promotion of reproductive health campaigns and family planning programs that included contraception. These campaigns and programs were challenged by churches and government representatives for religious and political reasons. The Roman Catholic Church, for example, has consistently opposed contraception, sterilization, and abortion as a general practice. Elsewhere, many feminist activists have advanced women’s reproduction as a component of human rights. The Fourth International Population Conference was organized by the United Nations, and it was held from 6th August to 14th August 1984 in Mexico City.

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The aim of this conference was to review and endorse the World Population Plan for Action agreed at the Bucharest Conference. The Fifth United Nations Conference on Population and Development was held in Cairo, Egypt, from 5th to 13th September 1994. Not less than 180 representatives from countries adopted a Program of Action on population and development for a 20-year period. Today, the United Nations Population Fund (UNFPA) is a part of the United Nations Development Group. Since 1969, it has promoted the right of every individual (woman, man, and child) to enjoy a healthy life with equal opportunity.

Contemporary Policies In China, the one-child policy introduced in 1978 is a significant population control measure that is still applicable. This policy is controversial both within and outside China owing to the issues it addresses, the measures applied, and its negative social consequences. In Iran, there has been a reduction in the national birthrate in recent decades. The government has publicized the benefits of small size families. The authorities have introduced mandatory contraceptive courses for males and females before a marriage license can be delivered. Today, several European countries have adopted social policies and programs that focus on community services that promote social care and welfare for women and children, and support child care, and parental leave with the aim of increasing low fertility rates and reducing ageing populations.

Conclusion The consequences of demographic growth or decline in relation to environmental, economic, and social change at local and larger levels cannot be challenged. Dealing with these issues should be a high priority for policy decision makers during this century on the understanding that there is no simple answers to these issues given that fundamental values are involved.

References Demeny P, McNicoll G (eds) (1998) The Earthscan reader in population and development. Earthscan, London Ehrlich P (1968) The population bomb. Ballantine, New York Ehrlich P, Ehrlich A (1990) The population explosion. Simon and Schuster, New York Ehrlich P, Holdren J (1971) The impact of population growth. Science 171:1212–1217 Malthus T (1798) An essay on the principle of population as it affects the future improvement of society. J. Johnson, London

Economic Growth and Global Change

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Julien Forbat

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Economic Growth and Global Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Environmental Damages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Social Inequalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Measures of Economic Growth and Well-Being . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Readings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

586 586 587 588 589 591 591 592

Abstract

The world economy has experienced an astonishing growth, estimated to have increased from about 100 billion dollars of GDP in the first century to more than 33,700 billion at the end of the twentieth century (Maddison 2001). Until recently, the global environmental impacts of this growth seemed extremely limited, even if some large-scale pollution was noted in Antiquity, for example, the atmospheric pollution stemming from the exploitation of copper mines by the Roman Empire (Boutron et al. 1996). Contemporary’s economic growth appears much more problematic and far more challenging for the future of mankind for several reasons. First, during recent decades, environmental damages have increased at a tremendous rate and reached a global scale, such as the case of greenhouse gases emissions. Second, this trend is reinforced by the growing impact of developing countries which were outside the realm of global economic growth. Third, the expansion of

J. Forbat Institute of Environmental Sciences, University of Geneva, Carouge, Switzerland e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_93, # Springer Science+Business Media Dordrecht 2014

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the world economy also tends to produce rising inequalities within societies. Finally, these negative impacts have been increasingly questioned since decoupling trends exist between economic growth and increasing well-being. Keywords

World economy • Environmental crisis • Externalities, social inequalities • Well-being indicators • Sustainable development

Definition Economic growth commonly refers specifically to an increase in monetary capital. The negative social and environmental consequences of global economic growth have increased to an unprecedented level as a result of the maintenance of unsustainable economic development in both developed and developing countries.

Economic Growth and Global Change If human populations have always had an impact on their environment, it was generally limited in its scale, even when this impact led or contributed to the extinction of an entire civilization, as, for example, in the cases of the Easter Island or the Mayas (Diamond 2005). In fact, anthropogenic changes to the environment were rare during most of human history. From the second half of the eighteenth century, the Industrial Revolution spread from the United Kingdom across Europe and the Western World. During the nineteenth century industrialization led to profound changes in the economic structure of many countries, which progressively went from being mainly agricultural to industrial, owing notably to the massive use of fossil energy. From 1820 to 1998, the GDP of Western countries (including Japan) jumped from 198 to 17,998 billion dollars (Maddison 2001). Following the demographic transition, countries experiencing such high rates of economic growth have benefited from a sharp rise in the standard of living of populations. However, this mode of economic growth has proven to be problematic in many respects because many developing countries are now concerned by its side effects. First, the environmental damages are not well taken into account. Second neither are the social costs of recent economic trends at the global level and third, the most widely used measure of economic growth and development – the GDP – fails to include many aspects of the notion of well-being. These three dimensions, namely, the environmental, social, and conceptual, are closely interrelated and provide a framework to describe the way economic growth impacts the world and its inhabitants.

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587

Concentrations of Greenhouse Gases from 0 to 2005

2000 1800

Methane (CH4) 350

1600

Nitrous Oxide (N2O) 1400 1200

CH4 (ppb)

CO2 (ppm), N2O (ppb)

Carbon Dioxode (CO2)

300 1000 800 250 0

600 500

1000 Year

1500

2000

Fig. 67.1 Atmospheric concentration of GHG (Data are from IPCC, Fig. 1 of FAQ 2.1 (2007b))

Environmental Damages The Roman Empire polluted the atmosphere by exploiting copper mines, but this represents a very rare documented case of premodern global environment impact. In fact, anthropogenic environmental changes are clearly a recent phenomenon pertaining to the development of industrial methods of production. Considering the various natural resources impacted by human activity, there is a clear trend associating greater levels of economic activity with higher levels of pollution or environmental degradation. For example, this is obvious in the case of greenhouse gases (GHG) emissions as shown in Fig. 67.1. The sharp rise in GHG emissions – with an increase of about 100 ppm from the middle of the eighteenth century until 2000 in the case of carbon dioxide – corresponds to the period when sources of fossil energy started to be widely used to produce goods and services or to develop more efficient networks of transportation. The consumption of fossil energy increased from only 3 metric tons of carbon in 1750 to more than 8,700 in 2008. Until the end of the nineteenth century, this was almost exclusively due to the use of coal (in 1885, on the 277 metric tons of carbon produced, 273 were from coal). However, with the discovery of petroleum, the trend of carbon emissions accelerated, and, in 1968, the carbon emissions related to the use of petroleum had exceeded those of coal (1,551 metric tons against 1448) (CDIAC 2011). There is now a large scientific consensus on the effect of anthropogenic GHG emissions on global temperatures. According to the Intergovernmental Panel on Climate Change (IPCC), anthropogenic emissions lead to a global surface warming

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whose negative consequences range from increased water stress for millions of people, damage from floods and storms, damage to natural ecosystems (stress and mortality of coral, for instance), to a heavier burden on health services (IPCC 2007a). More generally, the industrial economy tends to exert substantial pressure, both direct and indirect, on the stocks of natural ecosystems. Industrial fishing, for example, threatening marine ecosystems by overexploiting about 25 % of the world fishing stock (OECD 2001). In fact, many of the economic activities polluting the environment do so because the nonmonetary cost of the damages they cause are not taken into account; they remain externalities. Only a few examples of multilateral agreements that are intended to remedy the existence of negative environmental externalities are applicable today. One of them is the emissions trading system introduced by the Kyoto Protocol. This cap-and-trade system is based on economic incentives; countries and firms being encouraged to reduce their emissions of GHG as the price of the certificate allowing the emission of carbon dioxide increases on the market dedicated to it. Another example is the Montreal Protocol which led to the elimination of the production of chlorofluorocarbons (CFC) shown to be responsible for the depletion of the ozone layer; this multilateral agreement was ratified by 197 countries in 2012.

Social Inequalities Since the 1980s, and following a large movement of liberalization of financial markets in Western economies, GDP growth has progressively been in favor of the capital component of production at the expense of the labor component. This has implied a relative stagnation of salaries in comparison to the profits made by the capital investors. Consequently, inequalities within Western societies have increased to greater levels as measured by the Gini index. This index describes the distribution of incomes among a population in comparison to a hypothetical situation of perfect equality in which every person has the same income. The closer the Gini index is to 0 then the income distribution is more equal. On the contrary, when the Gini index is closer to 1 then there is a more unequal situation (a value of 1 would correspond to a distribution where one person has the entire national income). Wolff (2010) has, for example, highlighted the trend towards increased income inequality in the United States from the 1980s until the 2000s, with a Gini index rising from 0.480 in 1982 to 0.574 in 2006 (+20 %). Since the 1980s, world economic growth has been based on the relocation of many industrial activities from developed countries to developing countries mainly because of their relative low labor costs. Countries benefiting from this kind of transfer of activity (including China at the forefront since its economic liberalization in 1978) have experienced high levels of economic growth responsible for a huge increase of their GDP as well as increasing inequalities between regions

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70.0 60.0 50.0 40.0 30.0 20.0 10.0

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Fig. 67.2 Gini index for income in various countries (Estimated data are adapted from UNU-WIDER (2008))

(e.g., between rural and urban areas or, in the case of China, between coastal and inland regions), or between various socioeconomic groups (e.g., qualified versus less qualified workers). As in the case of Western countries, this led to an even greater increase of inequalities as expressed by the Gini index (see Fig. 67.2). The question of whether this trend towards rising income inequality will be lasting or not is at the core of the debate on the legitimacy of current world economic growth. Kuznets (1955) studied the link between economic growth and income inequality in Western countries from the end of the nineteenth century until the 1940s. He argued that this link has an inverted “U” shape; the level of income inequality rose in the initial phase of economic growth as only a few people benefit from it before it decreases during the economic transition to new economic sectors. However, as mentioned above, empirical cases do not tend to confirm this theoretical link. Western countries are now experiencing rising levels of income inequality, no clear prediction can be made about the future of developing countries, and recent examples even seem to invalidate the inverted “U” curve; for example, the case of the Eastern Asian miracle where rapid initial economic growth was not followed by an increase in income inequality, notably due to redistributive policies.

Measures of Economic Growth and Well-Being Economic growth is generally associated with an increase in the standard of living and thus of well-being. Nevertheless, the most often used measure of economic activity – the GDP – suffers from several shortcomings in an age of global

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1.00 0.90

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Fig. 67.3 Relation between HDI and GDP per capita (Data are adapted from UNDP (2012))

awareness on sustainability issues. It is indeed very problematic regarding both the environmental and social impacts of economic development. GDP measures economic flows and does not consider the state of the various environmental stocks used in the economic process; this means that any damage supported by the environment will not be reflected in the GDP. For example, GHG emissions or deforestation are never taken into account as affecting the level of economic activity and reducing its value. On the contrary, they would systematically be synonymous of an increase of the GDP value since they correspond to some economic activity. In short, any harm to the environmental capital tends to translate into an increase of GDP. Regarding the social consequences of economic growth, GDP does not indicate the level of inequality within a society. Information captured by the Gini index is completely absent from the GDP measure, even when considering its per capita value. A country may have a very high level of GDP per capita and still be characterized by important disparities between its different socioeconomic or cultural groups. For example, in Glasgow, people living in the Calton district have an average life expectancy of 54 years, 28 years less than inhabitants of Lenzie (WHO 2008). In fact, economic growth does not necessarily translate into an increase of well-being. Figure 67.3 shows a threshold above which any further increase in GDP per capita does not produce an improvement of the Human Development Index (HDI), a measure developed by the UN and including three components: health (life expectancy at birth), education (mean years of schooling and expected years of schooling), and standard of living (GNI per capita in PPP). For instance, in 2009, Qatar had a GDP per capita of 82,978 $ and a HDI of 0.82 when Estonia with a GDP per capita much lower (16,132 $) had a slightly higher HDI of 0.83. For these reasons, more and more scholars and institutions are arguing for new measures of economic growth, in order to better integrate environmental and social

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dimensions and to take into account the notion of well-being instead of focusing on a purely monetary approach. Among the indicators newly created, the Genuine Progress Indicator adds the value of voluntary activities and the environmental and social costs of economic activities to the traditional GDP value. There is also the Index of Economic Well-being created by the Centre for the Study of Living Standards in Canada. This index takes notably into account the notions of income distribution and economic security (Osberg and Sharpe 2012).

Conclusion The current mode of economic development is basically unsustainable as it combines disastrous impacts on the environment and on the populations affected by rising inequalities. A promising way of reducing the gap between monetary interests and the well-being of people and their environment lies in the advocacy of the principles of sustainable development. These principles encourage a systemic way of thinking and acting, so that the pursuit of any form of economic growth shall not be made at the expense of the long-term interests of human societies. Indeed, what is at stake concerns not only present generations but also future ones, because the global impacts of the economic growth are potentially irreversible. The debate on the way forward should therefore not be monopolized by any group of experts but rather be enlarged to include the whole society, given the fact it is above all an ethical issue.

References Boutron CF, Candelone J-P et al (1996) History of ancient copper smelting pollution during Roman and medieval times recorded in Greenland ice. Science 272(5259):246+ CDIAC (2011) Global, regional, and national annual CO2 emissions from fossil-fuel burning, cement manufacture, and gas flaring: 1751–2007. Carbon Dioxide Information Analysis Center, Oak Ridge Diamond J (2005) Collapse: how societies choose to fail or succeed. Viking, New York IPCC (2007a) Climate change 2007: synthesis report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. In: Core Writing Team, Pachauri RK, Reisinger A (eds). IPCC, Geneva IPCC (2007b) Climate change 2007: the physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds). Cambridge University Press, Cambridge Kuznets S (1955) Economic growth and income inequality. Am Econ Rev 45(1):1–28 Maddison A (2001) The world economy: a millenial perspective. OCDE, Paris OECD (2001) Sustainable development: critical issues. OECD, Paris Osberg L, Sharpe A (2012) Measuring economic insecurity in rich and poor nations. Center for the Study of Living Standards, Ottawa UNDP (2012) International human development indicators. Available via UNDP database. http:// hdrstats.undp.org/en/tables

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UNU-WIDER (2008) World income inequality database. UNU-WIDER, version 2.0c WHO (2008) Closing the gap in a generation: health equity trough action on the social determinants of health. WHO, Geneva Wolff EN (2010) Recent trends in household wealth in the United States: rising debt and the middle-class squeeze – an update to 2007. Levy Economics Institute, Annandale-on-Hudson

Additional Recommended Readings Jackson T (2009) Prosperity without growth? Sustainable Development Commission, London Stiglitz J, Sen A et al (2009) Report by the Commission on the Measurement of Economic Performance and Social Progress. Commission on the Measurement of Economic Performance and Social Progress, Paris

Building Performance and Climate Change

68

Richard Hyde

Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What Is Building Performance? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

The definition of energy efficiency and thermal comfort requires reworking in the current context of climate change and a carbon-constrained world. This elevates the importance of building performance, which can integrate both concepts in pursuit of current sustainability objectives. However, the gains made through improvements to building performance may not offset impacts from neither population growth nor more importantly, it is argued the increase in affluence of that population. These higher-level factors above building performance in world governance could be addressed at a global level with flow on standards for improved building performance. Keywords

Building performance • Climate change • Mitigation • Adaptation • Energy Efficiency • Thermal Comfort

R. Hyde Faculty of Architecture, Design and Planning, The University of Sydney, Sydney, NSW, Australia e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_97, # Springer Science+Business Media Dordrecht 2014

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Introduction In 1949 the world population was estimated to be 2.5 billion humans. Now 62 years later, the world’s population reached seven billion. This demographic trend has raised questions about the growth of this population, not so much the population size but the growth rate of the population; for example, the population of the world doubled in the period between 1960 and 2000 (World Bank 2012). Furthermore the rising material affluence of sectors of the world population and its use of technology to support growth in the built environment are occurring with erosion of the natural environment. At the end of the last century it became apparent that the environmental impact, such as that seen in climate change, arose from the changes in the dominant social paradigm and associated processes of this world population. The age of the industrial revolution and the consequent infrastructure as a model for servicing population growth has led to the expanding need for cities and buildings at the expense of the natural environment. As the world society moves into the new millennium, many have called for a new age of the environment (Wines 2000), based on a growing awareness of the potentially catastrophic impacts of human activity on the environment, and the need to develop a response to this challenge. Many question the sustainability of current practices. This response is coming from different sectors is society; for those concerned with the built environment, it has been widely accepted that climate change poses significant challenges for the building construction sector. First, a central question is how one might mitigate the effects of pollution from buildings such as carbon on the biosphere. Second, the adaptation of the attributes of building to the new climate conditions found or predicted in a particular region. Furthermore, the rate of climate change will prescribe the rate at which mitigation strategies (be they technical and or nontechnical) are implemented. The consequences for adaptation will be related. It can be argued that building performance therefore is a measure by which humans can assess their response to climate change. The inherent logic in this section is that the higher our performance standards for buildings then the more mitigation of the causes of climate change will be felt and, in theory, the less we will need to apply adaptation strategies. This section will examine what is building performance and where it can be implemented, how it can assist with addressing the issues of climate change, and who should take responsibility for actions in the domain of the built environment. However, climate change is only one of a number of issues concerned with sustaining the built environment. These issues pertain not only to environmental but also social and economic issues of sustainability.

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What Is Building Performance? Definitions Qualitative The term building performance is commonly associated with occupant comfort and energy efficiency. There are three characteristics for an energy-efficient building; it must have: • Efficient equipment and materials appropriate for the location and conditions • Amenities and services appropriate to the intended use • Operated in such a manner as to have a low energy use compared to other, similar, buildings (Meier et al. 2002). However, both these qualitative descriptions are underpinned by quantitative measures. Quantitative The term, such as thermal comfort, is converted to quantitative standards; in this case, quantitative standards commonly come from studies of human subjects and use normalized data to derive common acceptable levels of thermal comfort. For example, the thermal comfort level which most occupants find comfortable is when the air temperature is 25  C at 60 % humidity. Energy efficiency is a measure of the energy consumption usually on a yearly basis. For example, a conventional house may consume 4,000 kW h of energy per year, while an energy-efficient house may consume 2,000 kW h per year. As efficiency is measured by input/output*100, the energy-efficient house could be argued to be 50 % more efficient, since it saves $2,000 kW h which is 50 % of the energy consumed by the conventional house. The two quantitative standards of comfort and energy efficiency can be placed side by side. So when comparing two houses for energy efficiency, we would assume both had similar levels of thermal comfort; otherwise the comparison is unequal. It is also common to look at the processes within the house as well as the inputs and outputs. The energy uses are specific to a particular location, technologies, specific services, and occupant behavior (Fig. 68.1). Energy efficiency of buildings can be achieved in three ways: 1. Reducing the demand for electrical energy by better bioclimatic integration through passive design (i.e., natural heating and cooling and daylighting and using more efficient appliances) 2. Improving the efficiency of the supply of energy for particular services (i.e., use of on-site generation rather than sourced from the grid) 3. Removing the need for energy use though removing or moderating services; a house with six refrigerators may only need one. Using natural heating and cooling rather than space heating and cooling Two houses are compared for the amount and proportion of energy used across a particular function. The conventional suburban house in a moderate climate in

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Fig. 68.1 Household energy consumption per usage/sector. Left A conventional house. Right Energy-efficient house

a suburb, which is grid connected, uses a large amount of fossil fuels. However, the remote, energy-efficient autonomous (off grid) house uses about half to one-third of the fossil fuel energy of the conventional house. The largest energy consumption component is transport. Powered by solar electric systems and gas, it has what could be described as a higher level of building performance if energy consumption is used as the main criteria. In this way building performance can be used as a metric for comparing buildings. However, the definition of energy efficiency and thermal comfort requires reworking in the current context of climate change and a carbon-constrained world. This elevates the importance of building performance, which can integrate both concepts in pursuit of current sustainability objectives.

References Meier A, Olofsson T, Lamberts R (2002) What is an energy-efficient building? Proceedings of the ENTAC 2002 – IX meeting of technology in the built environment, Foz do Iguac¸u Wines L (2000) Green architecture. Taschen, Ko¨ln/New York World Bank (2012) Midyear estimates of the resident population. Public data available online, http://www.worldbank.org/ consulted on X/X/2013

Part VII Global Change and Human Health Ulisses E. C. Confalonieri

Global Change and Human Health, Introduction

69

Anthony J. McMichael

Keywords

Global change • Human health • Anthropocene • Environmental changes • Climate change • Systemic hazards

The phrase “global environmental change” (GEC) has now been circulating for a couple of decades, although never with a very clear definition. Hence the widespread misuse, indeed co-option, of the word “global” as a synonym for “international” and for assorted grand “global” statements about various widespread changes in human circumstances, behaviors, and environments. The advent of the concept of the “Anthropocene,” the proposed newly named geological epoch that has emerged over at least the past two centuries (Crutzen 2002; Steffen et al. 2007), is helping to bring the GEC concept into clearer focus. This new nomenclature recognizes that human numbers and aggregate economic weight have, together, become so large and generalized that our actions are now changing major components of the Earth System itself – the climate, the ocean chemistry, the stratosphere, the circulation of major elements (nitrogen, phosphorus, and others), the vitality of major ecosystems on land and sea, and the interacting panoply of species (Rockstrom et al. 2009). We are palpably moving out of the Holocene, the climatic, and environmental epoch that for 11,000 years has sustained the emergence and development of agriculture, settled living, and “civilizations” in a mostly post-hunter-gatherer world.

A.J. McMichael National Centre for Epidemiology and Population Health, The Australian National University, Canberra, Australia e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_100, # Springer Science+Business Media Dordrecht 2014

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This new concept, the Anthropocene, now provides us with the appropriate point of reference for discussing these truly new and important “global” environmental changes. In essence, these are “transboundary” changes with global or sub-global geographic span, and they typically entail disruptions or depletions of complex biophysical systems. They are qualitatively distinct from the classical environmental health hazards that arise from more localized environmental pollution – physical (ionizing and other radiation), chemical, or biological. These more global changes require new and better integrated research efforts, and fluency in systems science, if their origins, dimensions, and dynamics are to be understood. These are systemic environmental changes that require the attention and coordinated policy response of governments and communities everywhere if the working of the Earth System is to be steadied and even perhaps restored to a state that approximates the conditions under which existing life-forms and human societies have evolved (although this is not possible for extinguished species or dismantled ecosystems). The great significance of these GECs in relation to human health is that they act, over time, to weaken or disrupt the life-supporting properties of the Earth System. This category of systemic environmental risk to population health is not a problem caused by direct injury, toxicity, or defective hygiene (the familiar, more easily monitored and often preventable category of environmental health hazards). Rather, GECs represent a problem of impaired terrestrial and marine productivity (food), systemic micronutrient deficiencies, changes in the ranges, seasonality and rates of various infectious diseases (and the emergence of others, not previously identified in human populations), diminished surface water supplies and quality, losses of livelihoods and incomes, disruption and displacement of populations, and the resultant mental health, nutritional, infectious disease, and other health problems (Intergovernmental Panel on Climate Change (IPCC) 2007; McMichael and Lindgren 2011). Since the advent of agrarian living, humans have not encountered, on a large scale, a comparable set of systemic and ongoing shifts in the fundamental conditions and workings of the natural environment. That, however, is the additional level of environmental hazard that we now face from global climate change and the other GECs. These are “structural” systemic environmental health hazards that will extend many decades, probably centuries, into the future. A second typical feature of GECs as sources of risks to human health is that the risk impinges on whole communities, whole populations. The natural unit of observation, for research purposes, is therefore a group of people, not sets of separately measured and classified individuals. Mainstream environmental epidemiological research, conducted within custom-selected local study populations, makes informative comparisons between individuals and subgroups within that set of study subjects – comparing, for example, the health of children with high and low blood lead concentrations. But if climate change extends the range of malaria several hundred meters up the highland slopes, the associated change in the geography of risk impinges on whole communities. In that case, informative questions about the influence of climate change cannot be framed via comparisons of individuals; instead, communities must be compared with one another or with themselves over time.

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A third feature is that these GECs rarely operate in isolation of one another. This consideration has been overlooked in, for example, much of the past decade of research and writing on the current and future risks to health posed by climate change. Climate change, on its own, can cause life-threatening heat waves; and an increase in the flux of ultraviolet A and B through the stratosphere can increase the risk skin cancers. But for very many other risks to population health, the causal constellation entails a combination of GECs – either acting additively or (perhaps more likely) multiplicatively (i.e., interacting). Consider again the abovementioned ascent of malaria up the highland slopes: it could be due to a combination of land clearing, regional warming, and biodiversity losses that favor mosquito proliferation (e.g., declines in insect predators). Perhaps most obviously, regional food yields can be simultaneously affected by changes in climate, in freshwater supplies, in the circulation of biologically active nitrogen, in soil phosphorus concentrations, and in biodiversity losses (and associated influences on pest infestations). A fourth feature is that there are often recognizably different “layers” or categories of risks to health. These have often been viewed as a binary differentiation: direct and indirect health impacts (of climate change, in particular). As experience and understanding has grown, and as health researchers have become more inclusive and more landscape-aware in their thinking, so there have emerged proposals for more discriminating classifications, with three, four, or more categories. The human brain rather “likes” the number three, and the three-way classification of the impacts of climate change and other GECs into primary, secondary, and tertiary is gaining wider use (Butler and Harley 2010). This classification recognizes the broad penumbra of flow-on consequences for social stability, health, and survival that can result from the two “inner” categories and from social, economic, political and cultural losses, disruptions and dislocations. There is commensurately increasing attention being paid to the long-term mental health consequences of the impacts of repeated extreme weather events on farms, settlements, and trade; to the various health consequences (positive and negative) of displacement and planned relocation (McMichael et al. 2012); and to the openended range of health and survival consequences of tensions and conflict over diminishing or damaged environmental resources and conditions (e.g., access to river water). A fifth feature is that, while these are large-scale and often systemic shifts, perhaps progressing to cause irreversible state changes (Barnosky et al. 2012), they are slow moving, relative to a human lifetime. We cannot see them happening when we look out of the window – in contrast, say, to industrial chemical wastes that are visible and testable in river water, or urban air pollution, or a measurable surge in local ionizing radiation levels, or unrefrigerated food that is going “off” and which is replete with food-borne pathogens. This makes for multiple difficulties and challenges. Health impacts may accrue only marginally and rather surreptitiously and be hard to detect against all the usual background noise. The general public and governments have understandable doubts about “the science” (or at least its importance) because the empirical evidence of adverse impact is slow to emerge. The causal processes involved complex systems and, often, extended and diffuse

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pathways, and these are not well understood by the general public (many of whom carry simpler smoking-causes-lung-cancer models of disease causation in their heads). And since much, indeed most, of the concern about the risks to population health refers to the likely future progression of these GECS and their attendant risks to health, there is a necessary reliance on modeling techniques to provide reasonable, though never precise or certain, projections of likely future health impacts. Finally, the other distinctive feature that flows from these preceding features is that measurements, causal inference, quantitative causal attribution, types and distributions of uncertainty, and the communication of research findings and recommendations are typically complex and difficult. Much of this research requires the elucidation of how complex dynamic environmental and ecological systems behave and change under external human-generated “forcings.” It is simply not possible to say, therefore, how much of the downturn in grain yields in parts of, say, Western Africa is due to the background warming and the changes in the West African monsoon rains. The research community needs – and is now developing – new concepts, new analytic tools and criteria, new objectives (estimating risks may be less important than identifying key pathways that are susceptible to modification), and new modeling techniques to better understand the system dynamics and also to project likely future changes in exposures, vulnerabilities, and health outcomes for assumed sets of changes in GEC levels and profiles. The modeling of likely future health risks may not satisfy the tenets of science purists, as yet unweaned off their textbook reliance on classical experimental comparison. However, there is no reasonable alternative: our existing stocks of knowledge and theoretical understanding must be incorporated into modeling studies if we are to make socially useful, policy-relevant, estimates of how plausible future climatic and environmental changes would affect population health outcomes. How, for example, will the map of malaria and dengue fever change in future, region by region, as temperatures rise, rainfall alters, and humidity increases or decreases? How will staple food yields be affected by soil losses, nitrogen overload, climate change, and more (or less) frequent weather disasters, and how would this then affect levels of nutrition, starvation, and child deaths? The 2012 Rio + 20 Conference was a sobering reminder that the world community still finds it hard to recognize the existence and the ominous importance of these global environmental changes. And even where there is nascent or grudging recognition, there is not yet either the will or the readiness to act. We dissemble, we procrastinate, and we seem to pretend that fine words and written commitments to act in 5 years time will suffice. And then we tend to do it all again in 5 years time. We are, paradoxically, at a particular disadvantage as a species. Humans, unlike other species, can buffer themselves against many of the immediate (and not yet severe) stresses and health risks arising from these global environmental changes. That early “adaptive” protection can come from modifications to the built environment, trade, water engineering, agricultural practices and technologies, food aid, and other social and cultural factors. Some wealthier, well-governed and less

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geographically vulnerable societies may therefore notice little adversity in the initial stages of these great changes. The motivation to make transformative changes of the kind that are needed to aright and reverse these global environmental change processes is thus attenuated. Meanwhile, many of the world’s very vulnerable populations will suffer adverse health consequences much earlier (although, unfortunately for researchers, detailed environmental observations and health statistics are often not systematically available or those assessments are not yet even being made). One thing is very clear. The research community must continue to assemble more compelling, research evidence (while, as is likely, adverse health and other impacts occur more frequently, widely, and, hopefully, demonstrably). Evidence of that kind will help to break this futile cycle.

References Barnosky AD, Hadly EA, Bascompte J, Berlow EL, Brown JH, Fortelius M, Getz WM, Harte J, Hastings A, Marquet PA, Martinez ND, Mooers A, Roopnarine P, Vermeij G, Williams JW, Gillespie R, Kitzes J, Marshall C, Matzke N, Mindell DP, Revilla E, Smith AB (2012) Approaching a state shift in Earth’s biosphere. Nature 486:52–58 Butler CD, Harley D (2010) Primary, secondary and tertiary effects of the eco-climate crisis: the medical response. Postgrad Med J 86:230–234 Crutzen PJ (2002) Geology of mankind: the Anthropocene. Nature 415:23 Intergovernmental Panel on Climate Change (IPCC) (2007) In: Parry ML, Canzani OP, Palutikof JP, van der Linden PJ, Hanson CE (eds) Climate change 2007: impacts, adaptation and vulnerability contribution of working group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge/New York McMichael AJ, Lindgren E (2011) Climate change: present and future risks to health, and necessary responses. J Intern Med 270:401–413 McMichael CE, Barnett J, McMichael AJ (2012) An ill wind? Climate change, migration and health. Environ Health Perspect 120(5):646–654 Rockstrom J, Steffen W, Noone K, Persson A, Chapin FS, Lambin EF, Lenton TM, Scheffer M, Folke F, Schellnhuber HJ, Nykvist B, de Wit CA, Hughes T, van der Leeuw S, Rodhe H, So¨rlin S, Snyder PK, Costanza R, Svedin U, Falkenmark M, Karlberg L, Corell RW, Fabry VJ, Hansen J, Walker B, Diana Liverman D, Richardson K, Crutzen P, Foley JA (2009) A safe operating space for humanity. Nature 461:462–475 Steffen W, Crutzen PJ, McNeill JR (2007) The Anthropocene: are humans now overwhelming the great forces of nature. AMBIO: J Hum Environ 36(8):614–621

Climate Change, Extreme Weather and Climate Events, and Health Impacts

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Aderita Sena, Carlos Corvalan, and Kristie Ebi

Contents Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Key Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Extreme Weather and Climate Events Can Lead to Disasters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Health Impacts of Weather and Climate Extreme Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Extreme Weather Events Require Global to Local Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Keywords

Weather and climate extremes • Floods • Droughts • Hurricanes • Heat waves • Adaptation • Disaster risk reduction

Definitions Disasters the International Strategy for Disaster Reduction (ISDR) defines disasters as “a serious disruption of the functioning of a community or a society involving widespread human, material, economic, or environmental losses and impacts,

The views presented here are those of the authors and do not necessarily represent the views of their respective organizations. A. Sena (*) Ministry of Health, Brasilia, Brazil e-mail: [email protected] C. Corvalan Department of Medicine, Pan American Health Organization, Brasilia, Brazil e-mail: [email protected] K. Ebi ClimAdapt, LLC, Los Altos, CA, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_101, # Springer Science+Business Media Dordrecht 2014

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which exceeds the ability of the affected community or society to cope using its own resources.” Resilience is the ability of a natural or human system to absorb disturbances while retaining the same basic structure and ways of functioning, the capacity for self-organization, and the capacity to adapt to stress and change. Vulnerability is the susceptibility to harm, which can be defined in terms of a population or a location. From a health perspective, vulnerability can be defined as the summation of all risk and protective factors that ultimately determine whether a subpopulation or region experiences adverse health outcomes due to climate change. This includes factors that increase or decrease sensitivity, such as population demographics, and factors that determine the ability of a community or society to prepare for and recover from impacts, such as the status of and access to public health and health-care services. Risk is a product of the likelihood of exposure and the consequences of that exposure. It arises from the interaction of a physically defined hazard (e.g., floods), with the properties of the exposed system (its vulnerability). System vulnerability is a critical determinant of the risk a region or subpopulation faces when exposed to a particular hazard. Interventions to decrease vulnerability will decrease risk. A disaster risk management model used by the health sector has three phases with respective steps: (a) risk reduction (prevention, mitigation, and preparation), (b) disaster management (alert and response), and (c) recovery (rehabilitation and reconstruction). Climate extremes (extreme weather and extreme climate events) are defined as the occurrence of a value of a weather or climate variable above or below a threshold value near the upper or lower ends of observed values of the variable. Sources: (ISDR 2009a; PAHO/WHO 2011; IPCC 2012).

Key Information Climate change is becoming more evident at the global level, in part through changes in the frequency, intensity, and spatial extent of extreme weather and climate events. These events include temperature extremes, floods, droughts, severe storms, and forest fires. Although the evidence in terms of total health burdens and attribution to climate change needs strengthening, these events are increasingly affecting human health and well-being, as well as socioeconomic development. Concern is in particular focused on poor countries and population groups that are more likely to experience impacts when extreme events and disasters occur. Projections suggest that climate change will bring greater increases in extreme weather and climate events, with some events expected to increase in severity, frequency, and spatial extent (IPCC 2012). Extreme events can affect health directly (e.g., from extreme temperature). Others are complex or indirect (such as from floods, droughts, and hurricanes) because the resulting health impacts are dislocated in space and time or because the health impacts result from another

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change that occurred following an extreme event. For example, changes in temperature, precipitation, and humidity could affect the reproduction, development, and behavior of some vectors, leading to increases (or decreases) in the incidence of vector-borne diseases. Unplanned urbanization, deforestation, and destruction of ecosystems, coupled with poverty and inequalities, increase health vulnerabilities and the impact of extreme events. As a response to these risks, global to local policies are recommending actions to mitigate climate change, manage the risks of disasters, and protect health from adverse impacts. Plans include the revision of unsustainable development policies and actions to minimize the negative impacts on health and well-being.

Extreme Weather and Climate Events Can Lead to Disasters A recent assessment by the Intergovernmental Panel on Climate Change (IPCC), the Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX), concluded that a changing climate leads to changes in the frequency, intensity, duration, spatial extent, and timing of some weather and climate extremes (IPCC 2012). Continued greenhouse gas emissions will further increase the likelihood of even more extreme events. The health sector is insufficiently prepared to cope with the probability of increasing extreme events. The key approaches for managing the risks are disaster risk management and climate change adaptation. Both approaches aim to identify, deploy, and monitor efficient and effective actions to decrease exposure to weather and climate extremes and to increase resilience to events when they do occur. Disaster risk management has traditionally focused on the near term, while climate change adaptation generally has focused on increasing resilience to events over the coming decades. The SREX increased cooperation and collaboration cross these disciplines, highlighting that additional actions are needed at all levels, from local to international, to manage current and projected future extreme events. The risk of disasters is not evenly distributed among countries. The largest mortality risk is concentrated in developing countries, with 95 % of the deaths due to extreme events occurring in low-income countries, while most of the economic losses occur in high-income countries (IPCC 2012). Mortality risk from disasters is nearly 200 times higher in low-income countries as compared to OECD (Organization for Economic Co-operation and Development) countries when considering countries with the same numbers of exposed persons. For example, Japan and the Philippines are exposed to frequent tropical cyclones; Japan has a population of 22.5 million and the Philippines has a population of 16 million. When hit by tropical cyclones, the mortality rate in the Philippines is about 17 times higher than in Japan (ISDR 2009b). Small Island States have much higher relative risks compared to the size of their populations and economies. Vanuatu, for example, is the country with highest mortality risk per million inhabitants for tropical cyclones. At the global level, economic losses as measured by Gross Domestic Product (GDP) mortality risk from disasters is nearly 200 times are higher in low-income

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than OECD countries (when assessed in relation to their economies) as compared to OECD countries, considering countries with the same numbers of exposed persons. This also applies to economic losses in terms of Gross Domestic Product (GDP). Latin America and the Caribbean suffer losses six times higher than OECD countries, from floods, and South East Asia nearly 15 times higher in the case of floods. Risk arises from a range of causal factors related with the socioeconomic development of each country, not just the severity of the hazards or the level of exposure to them. Governance is an important factor determining risk. Countries with solid institutions, efficient early warning systems, plans for preparation and response to disasters, and governments with a policy for risk management tend to have lower levels of risk (ISDR 2009b). The SREX author teams assigned confidence levels to the key findings in the SREX report, where the confidence levels were based on three scales: evidence and agreement, confidence, and likelihood (Mastrandrea et al. 2010) Table 70.1 lists the high confidence key findings (where levels of confidence are on a five-point scale including high and very high). Table 70.1 High confidence key findings from the IPCC special report on managing the risks of extreme events and disasters to advance climate change adaptation Exposure and vulnerability Exposure and vulnerability are dynamic, varying across temporal and spatial scales, and depend on economic, social, geographic, demographic, cultural, institutional, governance, and environmental factors Settlement patterns, urbanization, and changes in socioeconomic conditions have all influenced observed trends in exposure and vulnerability to climate extremes Economic losses Economic losses from weather- and climate-related disasters have increased, but with large spatial and interannual variability Economic, including insured, disaster losses associated with weather, climate, and geophysical events are higher in developed countries. Fatality rates and economic losses expressed as a proportion of gross domestic product (GDP) are higher in developing countries Increasing exposure of people and economic assets has been the major cause of long-term increases in economic losses from weather- and climate-related disasters Disaster risk management The severity of the impacts of climate extremes depends strongly on the level of the exposure and vulnerability to these extremes Trends in exposure and vulnerability are major drivers of changes in disaster risk Development practice, policy, and outcomes are critical to shaping disaster risk, which may be increased by shortcomings in development Future climate extremes Locations currently experiencing adverse impacts such as coastal erosion and inundation will continue to do so in the future due to increasing sea levels, all other contributing factors being equal Changes in heat waves, glacial retreat, and/or permafrost degradation will affect high-mountain phenomena such as slope instabilities, movements of mass, and glacial lake outburst floods Changes in heavy precipitation will affect landslides in some regions (continued)

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Table 70.1 (continued) Changes in climate have the potential to seriously affect water management systems Increases in exposure will result in higher direct economic losses from tropical cyclones. Losses will also depend on future changes in tropical cyclone frequency and intensity Managing changing risks Effective risk management generally involves a portfolio of actions to reduce and transfer risk and to respond to events and disasters, as opposed to a singular focus on any one action or type of action Opportunities exist to create synergies in international finance for disaster risk management and adaptation to climate change, but these have not yet been fully realized Stronger efforts at the international level do not necessarily lead to substantive and rapid results at the local level Appropriate and timely risk communication is critical for effective adaptation and disaster risk management Adaptation efforts benefit from iterative risk management strategies because of the complexity, uncertainties, and long time frame associated with climate change

Health Impacts of Weather and Climate Extreme Events According to the World Health Organization (WHO), around one quarter of the global burden of disease and premature mortality is due to environmental factors, including climate change. Currently, the health impacts of climate change are relatively small, although the burden is likely to increase among vulnerable populations and regions as the climate continues to change (Pruss-Ustun and Corvalan 2006). The burden of disease attributable to climate change in the year 2000, compared with 1961–1990, from increases in temperature and changing precipitation patterns was estimated to be more than 150,000 deaths (McMichael et al. 2003). Flooding alone caused the loss of 192,000 healthy life years (measured as Disability Adjusted Life Years, DALYs). The risk of death from floods could increase fourfold by 2030. Extreme weather and climate events can have negative effects on human health, such as the 2003 European heat wave that caused tens of thousands excess deaths. Floods can increase the incidence of infectious diseases, such as diarrheal diseases, leptospirosis, and hepatitis A. The incidence and geographic range of climatesensitive vector-borne diseases and their reservoirs can be altered by changes in temperature, rainfall, and humidity and changes in land use and vegetation. Examples include dengue fever, malaria, and leishmaniasis. Changes in temperature, humidity, and rainfall patterns also are associated with asthma, other respiratory diseases, and respiratory infections. Other impacts may be more long term, such as changes in food availability leading to malnutrition. Climatic extremes also can result in mental health problems (Confalonieri et al. 2007; PAHO/WHO 2008; McMichael et al. 2003). Figure 70.1 shows examples of the relationship between climate change, climate disasters, and health outcomes, modulated by environmental vulnerability

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Fig. 70.1 Climate change, extreme weather and climate events, vulnerability, and health impacts

Climate disasters:

Climate change

Hurricanes Storms Floods Land slides Forest fires Droughts Heat-waves Cold spells

Environmental Vulnerability

Health Impacts: Injuries, traumas Infectious diseases (Vector, rodent, water and foodborne diseases) Malnutrition Mental disorders Cardiovascular, respiratory diseases

Social Vulnerability

(e.g., deforestation, housing in unsafe areas) and social vulnerability (e.g., poverty, lack of information). The pathways from extreme weather and climate events to their health impacts are often complex and indirect. Non-climate environmental and social factors can affect the dynamics of climate-sensitive health outcomes. Environmental vulnerability factors, including those resulting from human intervention, can exacerbate the impacts of extreme events through deforestation, land use change, water use change, and unplanned urbanization. Social vulnerability factors that can influence the severity of several health outcomes include demographic (e.g., age, migration, and population density), level of poverty, biological (vectors and infectious agents reproduction cycles and the immunological state of the population), effectiveness of and access to public health and health-care systems, and development policies, such as housing and basic sanitation services. Table 70.2 gives examples of extreme events, the impact process, and their health consequences.

Extreme Weather Events Require Global to Local Actions The World Conference for Disaster Reduction, held in 2005 in Kobe (Hyogo), Japan, approved the 2005–2015 Framework for Action with the theme of “building the resilience of nations and communities to disasters (also known as the Hyogo Framework for Action or HFA). The conference adopted 5 priorities of action: 1. Ensure that disaster risk reduction is a national and a local priority with a strong institutional basis for implementation. 2. Identify, assess, and monitor disaster risks and enhance early warning. 3. Use knowledge, innovation, and education to build a culture of safety and resilience at all levels. 4. Reduce the underlying risk factors. 5. Strengthen disaster preparedness for effective response at all levels. Based on these priorities, the HFA made specific recommendations. Priority action 4 made a special call to promote the goal of “hospitals safe from disasters”

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Table 70.2 Extreme weather and climate events and their health impacts Type of event Heat waves

Cold exposure

Floods, severe storms

Droughts

Impact process • Prolonged period of uncommon hot weather • Higher than normal high temperature • Higher than normal low (night) temperature • Low hydration • Susceptible population (e.g., the elderly, children, impaired health) • Underlying social conditions • Exposure to low temperature • Preexisting cardiovascular disease or respiratory conditions • Susceptible population (the elderly, children, preexisting health conditions including heart and respiratory disease) • Underlying social conditions • Alteration of quality and contamination of water and food (fungus, parasites, bacteria, viruses) • Changes in the development and behavior of vectors • Continued exposure to rain, water, and humidity • Changed behavior of poisonous animals • Exposure to high intensity winds • Exposure to electricity • Changed human behavior • Traumatic events, loss of family, and economic means • Changed food production and access • Underlying social conditions

• • • • • • • • • •

Extended period between rainfalls Limited access to potable water (quality and quantity) Increased contact with wild animals Limited water for hygiene Unsafe water storage Reduced or severely limited crop yields Reduced health of animals and livestock Drought-related wildfires Reduced air quality Underlying social conditions

Health impact • Heat stress • Cardiovascular, cerebrovascular, respiratory disease, and mortality

• Hypothermia, frostbite • Falls and related injuries • Acute respiratory conditions, asthma • Cardiovascular disease (myocardial infarction) • Water- and food-borne diseases (e.g., diarrheal diseases, cholera, typhoid fever, leptospirosis, hepatitis A, dermatoses) • Vector-borne diseases (e.g., changes in malaria, dengue, dengue hemorrhagic fever, yellow fever) • Respiratory infections,hypothermia • Drowning • Injuries, electric shock • Bites, including domestic and poisonous animals, snakes, spiders, scorpions • Violence including sexual violence • Psychosocial impacts; Posttraumatic stress disorder • Malnutrition • Increased water and food-borne diseases, including diarrheal disease • Vector- and rodent-borne diseases (e.g., dengue, West Nile virus, Hantavirus) • Malnutrition • Mental diseases, suicides • Respiratory diseases

that could continue to function efficiently in case of disasters (ISDR 2005). It also highlighted “the substantial reduction of disaster losses, in lives and in the social, economic, and environmental assets of communities and countries.” It called for the involvement and commitment of all concerned stakeholders including

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governments, regional and international organizations, civil society, the private sector, and the scientific community (ISDR 2005). At the country level, reduction of vulnerabilities is key to protect populations from weather and climate disasters. The impact of such disasters is dependent on the local vulnerabilities. Countries and populations more likely to suffer the highest health impacts are those that lack the means to protect themselves, often the poor, elderly, children, and those suffering from ill health. It is therefore essential to have national and local level contingency plans for disasters that include consideration of how a changing climate could alter future hazards. Planned actions must take into account exposure to extreme weather and climate events and the capacity of communities to avoid, prepare for, cope with, and recover from these events. It is necessary to implement actions to increase population resilience (Keim 2008). Well-defined policies at the national and subnational level promote effective interventions. International agencies incentivize the preparation of such strategies and policies at the national level, taking into account key geographical, social, cultural, environmental, and economic characteristics. Decision-makers, key professionals, and the affected population need to be included in developing specific measures to ensure effective response to adverse events. Such policies and measures should be key aspects of national adaptation plans to climate change. Countries are making advances in attaining their targets for the Millennium Development Goals. Climate change is a threat to maintaining their achievements. Following the United Nations Conference on Sustainable Development held in Rio de Janeiro in June 2012, countries agreed to the UN Outcome Document, “The Future We Want” (UN 2012), where a section is dedicated to disaster risk management. It calls for a better integration between strategies for disaster risk management and climate change adaptation, and on climate change, the report calls for adaptation as an immediate and urgent global priority. The report also recommends the formulation of “sustainable development goals.” Climate change, disasters, and health are important determinants of sustainable development; therefore, actions to combat climate change, manage disaster risks, and improve health promote alignment with global agreements.

References Confalonieri U et al (2007) Human health. In: Parry ML et al (eds) Contribution of working group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK International Strategy for Disaster Reduction (2005) Hyogo framework for action 2005–2015. Building the resilience of nations and communities to disasters, Kobe International Strategy for Disaster Reduction (2009a) UNSDR terminology on disaster risk reduction. UN, Geneva International Strategy for Disaster Reduction (2009b) Global assessment report on disaster risk reduction. Risk and poverty in a changing climate. Invest today for a safer tomorrow. UN, Geneva

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IPCC (2012) Summary for Policymakers. In: Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation [Field, C.B., V. Barros, T.F. Stocker, D. Qin, D.J. Dokken, K.L. Ebi, M.D. Mastrandrea, K.J. Mach, G.-K. Plattner, S.K. Allen, M. Tignor, and P. M. Midgley (eds.)]. A Special Report of Working Groups I and II of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK, and New York, NY, USA, pp. 1–19 Keim MR (2008) Building human resilience: the role of public health preparedness and response as an adaptation to climate change. Am J Prev Med 35(5):508–516 Mastrandrea MD, Field CB, Stocker TF, Edenhofer O, Ebi KL, Frame DJ, Held H, Kriegler E, Mach KJ, Matschoss PR, Plattner G-K, Yohe GW, Zwiers FW (2010) Guidance note for lead authors of the IPCC 5th assessment report on consistent treatment of uncertainties. http://www. ipcc.ch McMichael J et al (eds) (2003) Climate change and human health – risks and responses. World Health Organization, Geneva Pan-American Health Organization & World Health Organization (2008) Climate change and human health- risks and responses, Revised summary 2008. PAHO, Washington Pan-American Health Organization & World Health Organization (2011) Vulnerability and adaptation assessment. WHO, Geneva Pruss-Ustun A, Corvalan C (2006) Preventing disease through healthy environments. World Health Organization, Geneva United Nations (2012) The future we want. UN, New York

Waterborne and Foodborne Diseases, Climate Change Impacts on Health

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Corinne Schuster-Wallace, Sarah Dickin, and Chris Metcalfe

Contents Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Context . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Waterborne Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Foodborne Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

Climatic conditions strongly impact the incidence and transmission of many waterborne and foodborne diseases. Climate change may increase the risk to these illnesses by influencing weather patterns, resulting in warmer temperatures, more variable rainfall events and decreased water availability. The extent to which these changes will increase the burden of disease is uncertain, however there are implications for many exposure pathways. In addition to infectious disease agents, the transport and fate of chemicals such as heavy metals and organic compounds in the environment will be affected by changing water flows. In water stressed areas, reductions in fresh water availability due to climate

C. Schuster-Wallace (*) Institute for Water, Environment and Health, United Nations University, Hamilton, ON, Canada e-mail: [email protected] S. Dickin School of Geography and Earth Sciences, McMaster University, Hamilton, ON, Canada United Nations University Institute for Water Environment and Health, Hamilton, ON, Canada e-mail: [email protected] C. Metcalfe Trent University and United Nations University, Peterborough, ON, Canada e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_102, # Springer Science+Business Media Dordrecht 2014

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change will have critical implications for water quality, disproportionately affecting vulnerable groups such as children. Decreased water resources will also have consequences for safe food processing and preparation. Keywords

Foodborne • Waterborne • Contaminants • Climate change • Emerging

Definitions Foodborne disease is defined by WHO as caused by toxic or infectious agents acquired through the ingestion of food (http://www.who.int/topics/ foodborne_diseases/en/index.html). Waterborne disease can then be defined as caused by toxic or infectious agents acquired through the ingestion or inhalation of water. Water-washed disease results from infectious agents acquired through dermal contact with contaminated water or where there is insufficient water for proper hygiene practices, thereby including diseases acquired through the fecal-oral route within this definition (e.g., Zwane and Kremer 2007).

Context Climate change is expected to have far-reaching consequences for human health, with waterborne and foodborne illnesses constituting a major area of concern. While difficult to assess (e.g., Flint et al. 2005), estimates suggest that there is currently a significant health burden associated with foodborne and waterborne disease. Globally there are 2.5 million cases of diarrhea a year in children under 5 (UNICEF and WHO 2009). In 2010, 800,000 children under 5 died as a result of € un et al. (2008) estimated the global burden of diarrhea (UNICEF 2012). Pr€uss-Ust€ disease associated with poor access to drinking water, inadequate sanitation and hygiene, and poor water management to be almost 10 % of the global burden of disease. While this value encompasses more than simply waterborne disease, it represents a significant preventable proportion of disease worldwide. Similarly with foodborne diseases, the global estimate for non-typhoidal Salmonella provides an indication of the magnitude of the problems associated with foodborne disease more generally. Majowicz et al. (2010) estimated that more than 150,000 deaths and 93 million cases of gastroenteritis attributable to Salmonella occur every year, with 86 % of these likely foodborne. Many studies have been summarized at the national (e.g., Charron et al. 2008) and international (e.g., Confalonieri et al. 2007) scales, indicating that the number of cases will only increase over time as the full impacts of climate change are realized. Moreover, with an increasingly global economy and community, pathogens, diseases, and contaminated foods can be transported around the world in a matter of days. The European outbreak (2011) of Escherichia coli O104:H4 underscores the problems that are faced, including the wide geographic distribution of sources of produce, the money

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involved in food exports, and emerging pathogens. As concluded by Bielaszewska et al. (2011: p. 676), “this outbreak tragically shows that blended virulence profiles in enteric pathogens introduced into susceptible populations can have serious consequences for infected people.” Health transitioning, from acute infectious diseases to chronic and noncommunicable diseases, with economic development implies a geographic divide in emphasis on acute versus chronic diseases related to water and food. Thus, health concerns tend to be polarized within the food and water context, between pathogenic contaminants and chemical contaminants. As a result, many higher-income countries have become complacent about waterborne diseases in particular, believing that multiple barrier approaches to treatment and distribution nullify their risk of exposure. Clearly, it is impossible to be risk-free, and climate change impacts will make this increasingly difficult depending on the region. These impacts could occur through more intense precipitation events and warmer temperatures (especially minimum values) that can result in changes in vegetation patterns, expansion and contraction of habitats for diseases, changes in chemical use, and physical modification of both pathogens and chemicals.

Waterborne Disease Climate change will greatly impact the hydrological cycle, which has significant implications for waterborne disease. These changes will impact exposure to acute infections caused by pathogens as well as the environmental distribution and toxicity of chemical pollutants causing chronic health effects. Waterborne diseases caused by viruses, bacteria, and protozoa are spread through contaminated drinking water or recreational water. Their transmission and survival in the environment are greatly affected by precipitation and temperature conditions, which are susceptible to climate variability (Charron et al. 2005; Thomas et al. 2006). Rainfall is often associated with contamination events, washing pathogens such as E. coli and Cryptosporidium into water supplies (Curriero et al. 2001; Schuster et al. 2005) and contaminating recreational bathing areas (e.g., Patz et al. 2008). Climate change is expected to increase the frequency of weather extremes, resulting in more floods and droughts which pose risks to human health (Costello et al. 2009). In water-scarce regions, droughts place additional stress on water supplies. This forces people to travel greater distances to access water, and can deteriorate sanitation and hygiene conditions. In flooded regions, excess water may damage treatment infrastructure and lead to sewage overflow, resulting in more frequent contamination events. Moreover, changes to surface water and groundwater flows due to climate change will impact the quantity and quality of water resources in many regions. Populations relying on glacial meltwater will be forced to turn to less reliable sources (Immerzeel et al. 2010). In many water bodies the increases in water temperatures may expand the occurrence of cyanobacterial blooms which produce harmful toxins (Paerl and Huisman 2009). Similarly, increased incidence of diseases which thrive in warm water, such as Legionnaire’s

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disease, cryptococcosis, and cholera, may be observed due to climate change (McMichael et al. 2006; Greer et al. 2008; Raffa et al. 2012). In addition to waterborne infections, human health effects resulting from exposure to chemical contaminants will be impacted by climate change (Noyes et al. 2009; Pangare and Idris 2012). Climate change will affect the types and quantities of chemical contaminants that are released and the transport and fate of chemicals in the environment. For some classes of chemicals, such as pesticides, biocides, and pharmaceuticals, use will increase in response to the need for increased agricultural production as well as the expanding number and distribution of animal and plant pests and human diseases (Boxall et al. 2009; Tirado et al. 2010; Royal Commission on Environmental Pollution 2011). In countries with expanding economies, the use of chemicals for domestic use (e.g., cleaners, detergents, disinfectants) will also increase. Trends towards urbanization will result in increased discharges of both domestic and industrial wastewater that contain chemical contaminants (Evans et al. 2012). Demand for nonrenewable resources will increase contamination of ground and surface water by the mining industry and the fossil fuel energy sector. In other cases, pollution of water resources from emissions may decrease. For example, decreases in fossil fuel use, resulting from greenhouse gas mitigation policies, will reduce ground-level air pollution by particulate matter in urban areas (Bell et al. 2008). For legacy contaminants, such as mercury and persistent organic pollutants (POPs) that were released into the environment in the past and now reside in soil and sediments, climate change may alter the environment in such a way that the contaminants are released more rapidly. Rising temperatures would be expected to accelerate the conversion of mercury to methyl mercury (Downs et al. 1998) and the volatilization of POPs from contaminated sources, such as buildings and electrical equipment (Bogdal and Scheringer 2011). The fate and transport of chemicals in the natural environment will also change in the future. Rising temperatures will increase rates of volatilization and thereby the long-range transport of POPs (Armitage et al. 2011) and local exposure to pesticides (Boxall et al. 2009). Climate-induced changes in hydrological cycles and regimes will change how contaminants are transported into the aquatic environment, as well as the dilution potential of rivers and streams. Increases in the occurrence of extreme weather events, such as floods and droughts, will alter the mobility of contaminants (Manuel 2006). In agricultural areas, changes in irrigation practices, such as reuse of wastewater, could move contaminants from water bodies onto land (Tirado et al. 2010). As well as affecting contaminant inputs, transport, and fate, global change will also affect the structure and functioning of ecosystems. It has been estimated that 40 % of humanity is already competing directly with nature for water (Safreil 2011), and this is affecting the life-supporting capacity of ecosystems. Climate change and nutrient releases will also affect the rates of formation and the geographical distribution of algae that produce natural toxins (Marques et al. 2010). Reduced ecosystem services may also affect the distribution and prevalence of vector-borne diseases, such as malaria and dengue (Sutherst 2004).

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Foodborne Disease In a similar manner to waterborne disease, climate change presents a range of challenges to maintaining food safety and availability at many stages in the supply chain, including crop production, feed production and animal health, fisheries and aquaculture, food trade, and food processing and handling (Tirado et al. 2010). While disputed by some (e.g., Lake et al. 2009), the likely increase in risk of exposure takes two forms: environmental and behavioral. Increased environmental exposure results from changes in the physical environment, such as air temperature (maximum, minimum, and mean values) and precipitation patterns. Increasing temperatures affect levels of pathogen and pest populations and change the distribution and incidence of animal and vegetable diseases. For example, foodborne diseases such as salmonellosis have been found to increase with each degree increase above 6  C (Kovats et al. 2004). Contamination of fisheries and aquaculture operations, such as oyster beds, has been linked to heavy rainfall events (Doyle et al. 2004), and warming ocean water has already led to an expansion of pathogens previously limited to warmer waters. Specifically, Vibrio parahaemolyticus outbreaks due to oyster consumption have been reported in areas that were previously too cold to support the pathogen survival (Drake et al. 2007). Climate change may also influence the occurrence of mycotoxins, toxic substances produced by fungi which grow on a variety of crops. These fungi are influenced by environmental conditions, such as temperature, humidity, and plant water stress (e.g. Paterson and Lima 2011). This is especially a challenge in developing regions with less capacity and food safety regulations to protect crops and consumers from the toxins. The mycotoxin aflatoxin found in grains has had severe impacts on health in Kenya in recent years (Daniel et al. 2011). While flooding can lead to contamination of soil and animal feed (FAO 2005), drought conditions can have significant consequences through increases in pests and blights (Gregory et al. 2009). The impacts of climate change on food production will require adaption strategies to ensure food safety and security. Subsequent health impacts include malnutrition (crop failure) and chronic outcomes that will likely take the form of increased fertilizers and pesticide use, increasing human exposure to higher levels of chemicals (Boxall et al. 2009). These more intense exposures could have long-term consequences on health that are still poorly understood. In some areas, water scarcity necessitates the use of wastewater for irrigation. While important for food security, there are significant biological and chemical risks associated with production and consumption of these crops. Behavioral responses that increase exposure risk to both waterborne and foodborne diseases comprise changes in practice mainly as a result of warmer weather. For example, an increase in hot days during the summer can result in an increased number of people bar-b-queing and picnicking. In turn, this increases the likelihood of consumption of undercooked foods and/or foods that have been sat out in the sun for long periods of time, both of which are risk factors for foodborne disease. This seasonal pattern has been identified in previous studies (e.g., Fleury et al. 2006). Other changes in practice include increased frequency of camping and

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recreational activities near or in water. At the end of the consumer supply chain, warming temperatures impacts food handling and preparation, increasing the risk of consuming contaminated foods and requiring increased emphasis on proper handling and storage of food under warmer temperatures. In some arctic regions, warming temperatures are impacting traditional food handling and preparation practices (Ford 2012) as well as availability. In countries reliant on air conditioning, increased strain on electricity grids can have implications for brownouts and blackouts and therefore food storage and treated drinking water supplies.

References Armitage JM, Quinn CL, Wania F (2011) Global climate change and contaminants – an overview of opportunities and priorities for modelling the potential implications for long-term human exposure to organic compounds in the Arctic. J Environ Monit 13:1532–1546 Bell ML, Davis DL, Cifuentes LA, Krupnick AJ, Morgenstern RD, Thurston GD (2008) Ancillary human health benefits of improved air quality resulting from climate change mitigation. Environ Health 7:41–45 Bielaszewska M, Mellmann A, Zhang W, Ko¨ck R, Fruth A, Bauwens A, Peters G, Karch H (2011) Characterisation of the Escherichia coli strain associated with an outbreak of haemolytic uraemic syndrome in Germany, 2011: a microbiological study. Lancet Infect Dis 11:671–676 Bogdal C, Scheringer M (2011) Release of POPs to the environment. In: UNEP/AMAP expert group report climate change and POPs: predicting the impacts. UNEP/AMAP, Geneva Boxall AB, Hardy A, Beulke S, Boucard T, Burgin L, Falloon PD, Haygarth PM, Hutchinson T, Kovats RS, Leonardi G, Levy LS, Nichols G, Parsons SA, Potts L, Stone D, Topp E, Turley DB, Walsh K, Wellington EMH, Williams RJ (2009) Impacts of climate change on indirect human exposure to pathogens and chemicals from agriculture. Environ Health Perspect 117:508–514, http://dx.doi.org/10.1289/ehp.0800084 Charron D, Fleury M, Lindsay LR, Ogden N, Schuster CJ (2008) The impacts of climate change on water-, food-, vector and rodent-borne diseases. In: Human health in a changing climate: a Canadian assessment of vulnerabilities and adaptive capacity, Chap. 5. Health Canada. http://www.climateneeds.umd.edu/reports/Health%20Canada-Human%20Health%20in%20a% 20Changing%20Climate.pdf. Accessed Aug 2012 Confalonieri U, Menne B, Akhtar R, Ebi KL, Hauengue M, Kovats RS, Revich B, Woodward A (2007) Human health. In: ParryML, Canziani OF, Palutikof JP, van der Linden PJ, Hanson CE (eds) Climate change 2007: impacts, adaptation and vulnerability. Contribution of working group II to the fourth assessment report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, UK, pp 391–431 Costello A, Abbas M, Allen A, Ball S, Bell S, Bellamy R et al (2009) Managing the health effects of climate change. Lancet 373:1693–1733 (Lancet-University College London Institute for Global Health Commission) Curriero FC, Patz JA, Rose JB, Lele S (2001) The association between extreme precipitation and waterborne disease outbreaks in the United States, 1948–1994. Am J Public Health 91:1194–1199 Daniel JH, Lewis LW, Redwood YA, Kieszak S, Breiman RF, Flanders WD, Bell C, Mwihia J, Ogana G, Likimani S, Straetemans M, and McGeehin MA (2011) Comprehensive assessment of maize aflatoxin levels in eastern Kenya, 2005–2007. Environ Health Perspect 119:1794–1799 Downs SG, MacLeod CL, Lester JN (1998) Mercury in precipitation and its relation to bioaccumulation in fish: a literature review. Water Air Soil Poll 108:149–187. doi:10.1023/ A:1005023916816 Doyle A, Barataud D, Gallay A, Thiolet JM, Le Guyaguer S, Kohli E, Vaillant V (2004) Norovirus foodborne outbreaks associated with the consumption of oysters from the Etang de Thau, France, December 2002. Euro Surveill 9(3):24–26

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Drake SL, DePaola A, Jaykus L-A (2007) An overview of Vibrio vulnificus and Vibrio parahaemolyticus. Compr Rev Food Sci Food Saf 6:120–144. doi:10.1111/j.15414337.2007.00022.x Evans AEV, Hanjra MA, Jiang Y, Qadir M, Drechsel P (2012) Water quality: assessment of the current situation in Asia. Water Res Dev 28:195–216 FAO (2005) Food safety guidance in emergency situations. UN Food and Agriculture Organisation. Available from: www.fao.org/docs/eims/upload/215251/emergency.pdf. Accessed Aug 2012 Fleury M, Charron DF, Holt JD, Allen OB, Maarouf AR (2006) A time series analysis of the relationship of ambient temperature and common bacterial enteric infections in two Canadian provinces. Int J Biometeorol 50(6):385–391 Flint JA, Van Duynhoven YT, Angulo FJ, DeLong SM, Braun P, Kirk M, Scallan E, Fitzgerald M, Adak GK, Sockett P, Ellis A, Hall G, Gargouri N, Walke H, Braam P (2005) Estimating the burden of acute gastroenteritis, foodborne disease, and pathogens commonly transmitted by food: an international review. Clin Infect Dis 41:698–704 Ford JD (2012) Indigenous health and climate change. Am J Public Health 102(7):1260–1266. doi:10.2105/AJPH.2012.300752 Greer A, Ng V, Fisman D (2008) Climate change and infectious diseases in North America: the road ahead. Can Med Assoc J 178:715–722 Gregory PJ, Johnson SN, Newton AC, Ingram JSI (2009) Integrating pests and pathogens into the climate change/food security debate. J Exp Bot 60:2827–2838. doi:10.1093/jxb/erp080 Immerzeel WW, van Beek LPH, Bierkens MFP (2010) Climate change will affect the Asian water towers. Science 328:1382–1385 Kovats RS, Edwards SJ, Hajat S, Armstrong BG, Ebi KL, Menne B, The Collaborating Group (2004) The effect of temperature on food poisoning: a time-series analysis of salmonellosis in ten European countries. Epidemiol Infect 132(3):443–453. doi:http://dx.doi.org/10.1017/ S0950268804001992 Lake IR, Gillespie IA, Bentham G, Nichols GL, Lane C, Adak GK, Threlfall EJ (2009) A re-evaluation of the impact of temperature and climate change on foodborne illness. Epidemiol Infect 137:1–10 Majowicz SE, Musto J, Scallan E, Angulo FJ, Kirk M, O’Brien SJ, Jones TF, Fazil A, Hoekstra RM, for the International Collaboration on Enteric Disease ‘Burden of Illness’ Studies (2010) The global burden of non-typhoidal Salmonella gastroenteritis. Clin Infect Dis 50(6):882–889 Manuel M (2006) In Katrina’s wake. Environ Health Perspect 114:A32–A39 Marques A, Nunes ML, Moore SK, Strom MS (2010) Climate change and seafood safety: human health implications. Food Res Int 43:1766–1779 McMichael AJ, Woodruff RE, Hales S (2006) Climate change and human health: present and future risks. Lancet 11(367;9513):859–869 Noyes PD, McElwee MK, Miller HD, Clark BW, VanTiem LA, Walcott KC, Erwin KN, Levin ED (2009) The toxicology of climate change: environmental contaminants in a warming world. Environ Int 35:971–986 Paerl HW, Huisman J (2009) Climate change: a catalyst for global expansion of harmful cyanobacterial blooms. Environ Microbiol Rep 1:27–37. doi:10.1111/j.1758-2229.2008.00004.x Pangare G, Idris L (2012) Water and health security. In: Bigas H, Morris T, Sandford B, Adeel Z (eds) The global water crisis: addressing an urgent security issue (Series ed: Axworthy TS). UNU-INWEH, Walter and Duncan Gordon Foundation and InterAction Council, UNU-INWEH Hamilton, Canada, pp 77–83 Paterson RRM, Lima N (2011) Further mycotoxin effects from climate change. Food Res Int 44:2555–2566 Patz JA, Vavrus SJ, Uejio CK, McLellan SL (2008) Climate change and waterborne disease risk in the Great Lakes region of the U.S. Am J Prev Med 35:451–458 € un A, Bos R, Gore F, Bartram J (2008) Safer water, better health: costs, benefits and Pr€uss-Ust€ sustainability of interventions to protect and promote health. World Health Organization,

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Geneva. Available from: http://www.who.int/quantifying_ehimpacts/publications/saferwater/ en/index.html. (Accessed Aug 2012) Raffa RB, Eltoukhy NS, Raffa KF (2012) Implications of climate change (global warming) for the healthcare system. J Clin Pharm Ther. doi:10.1111/j.1365-2710.2012.01355.x Royal Commission on Environmental Pollution (2011) Demographic change and the environment. RCEP 29th report, RCEP, London Safreil U (2011) Balancing water for people and nature. In: Garrido A, Ingram H (eds) Water for food in a changing world: contributions from the Rosenberg International Forum on Water Policy. Routledge, London and New York, pp 135–170 Schuster CJ, Ellis AG, Robertson WJ, Charron DF, Aramini JJ, Marshall BJ, Madeiros DT (2005) Infectious disease outbreaks related to drinking water in Canada, 1974–2001. Can J Public Health 96(4):254–258 Sutherst RW (2004) Global change and human vulnerability to vector-borne diseases. Clin Microbiol Rev 17(1):136–173. doi:10.1128/CMR.17.1.136-173.2004PMCID: PMC321469 Thomas MK, Charron DF, Waltner-Toews D, Schuster CJ, Maarouf AR, Holt J (2006) A role of high impact weather events in waterborne disease outbreaks in Canada, 1975–2001. Int J Environ Health Res 16(3):167–180 Tirado MC, Clarke R, Jaykus LA, McQuatters-Gollop A, Frank JM (2010) Climate change and food safety: a review. Food Res Int 43(7):1745–1765 UNICEF, WHO (2009) Diarrhoea: why children are still dying and what can be done. Available from: http://whqlibdoc.who.int/publications/2009/9789241598415_eng.pdf. Accessed Aug 2012 UNICEF (2012) Pneumonia and diarrhoea tackling the deadliest diseases for the world’s poorest children. Available from: http://www.unicef.org/eapro/Pneumonia_and_Diarrhoea_Report_2012.pdf. Accessed Aug 2012 Zwane A, Kremer M (2007) What works in fighting diarrheal diseases in developing countries? A critical review. World Bank Res Obser 22:1–24

Additional Recommended Reading Charron DF, Edge T, Fleury MD, Galatianos W, Gillis D, Kent R, Maarouf AR, Neudoerffer C, Schuster CJ, Thomas MK, Waltner-Toews D, Valcour J (2005) Links between climate, water and waterborne illness, and projected impacts of climate change. Final Technical Report to HPRP, File No. 6795-15-2001-4400016c Portier CJ, Thigpen Tart K, Carter SR, Dilworth CH, Grambsch AE, Gohlke J, Hess J, Howard SN, Luber G, Lutz JT, Maslak T, Prudent N, Radtke M, Rosenthal JP, Rowles T, Sandifer PA, Scheraga J, Schramm PJ, Strickman D, Trtanj JM, Whung P-Y (2010) A human health perspective on climate change: a report outlining the research needs on the human health effects of climate change. Environmental Health Perspectives/National Institute of Environmental Health Sciences, Research Triangle Park. doi:10.1289/ehp.1002272. Available: www. niehs.nih.gov/climatereport. Accessed Aug 2012 Schuster-Wallace CJ, Grover VI, Adeel Z, Confalonieri U, Elliott S (2008) Safe water as the key to global health. United Nations University Institute for Water, Environment and Health. Available from: http://inweh.unu.edu/wp-content/uploads/2013/05/SafeWater_Web_version.pdf. Accessed Aug 2012 Semenza JC, Herbst S, Rechenburg A, Suk JE, Ho¨ser C, Schreiber C, Kistemann T (2012) Climate change impact assessment of food and waterborne diseases. Crit Rev Environ Sci Technol 42(8):857–890

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Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Keywords

Emerging infectious disease • Vector-borne disease • Climate variability • Climate change • Adaptation

Definition All vector-borne diseases are climate sensitive: climate acting as an important driver of spatial and seasonal patterns, year-to-year variations (including epidemics), and longer-term geographic trends. Although climate is only one of the many drivers of the dynamics of disease vectors (ticks and insects) and the pathogens they carry, public health researchers, policy makers, and practitioners are increasingly concerned about the potential impact of climate change on the health of populations. However, to make progress, the public health community needs to understand the nature of the impact of climate variability and change

M.C. Thomson International Research Institute for Climate and Society, The Earth Institute, and Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_103, # Springer Science+Business Media Dordrecht 2014

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on vector-borne and emerging diseases, the predictability of the climate, and the potential for climate knowledge and information to inform health decision-making.

Introduction By their very nature, all vector-borne diseases have the potential to respond to changing patterns in the climate, especially rainfall. Humid environments favor insect survival. This is because the small size and large body surface to volume ratio makes them highly susceptible to desiccation – eliciting a host of ecological, biological, and behavioral responses. At rest, insects and ticks will be at the temperature of the microenvironment they inhabit as will the pathogens they carry. Since the development rates of both vectors and pathogens are governed by temperature, this has important implications in a warming world. Climate and other environmental factors (such as soil type, topography, and land use) also contribute to vector-borne disease transmission dynamics through, for example, the availability of breeding sites and the presence of food sources and reservoir hosts. Over the last few decades, many diseases never previously reported in humans have emerged (Jones et al. 2008) – a significant number of which are vector-borne (Rosenberg and Beard 2011). New disease outbreaks are commonly associated with zoonosis (with pathogens passing to humans from wild or domesticated animals). They can be catastrophic for poorer economies, particularly when much of the population (now at risk from a new disease) is dependent on livestock that can no longer be safely eaten or sold. In a changing climate and globalized world, where humans and domesticated/wild animals interactions are intensifying, it is expected that disease emergence from zoonosis will increase. At the same time, more established diseases are now the focus of major control and elimination programs (Feachem et al. 2010). A review of the scientific literature on climate and the most important infectious diseases causing considerable morbidity and mortality worldwide highlights the importance of vector-borne diseases such as malaria and dengue (Kelly-Hope and Thomson 2008). Other parasitic, viral, and bacterial diseases are gaining increasing attention and many studies focus on the impact of climate on geographic distribution, seasonality, interannual variability, or climatic shifts with a focus on the potential predictability of epidemics (for acute diseases) or geographic shifts in disease distribution (for both acute and chronic diseases). Of particular importance have been studies on the relationship of the El Nin˜o–Southern Oscillation (ENSO) phenomenon (a periodic warming of sea surface temperatures in the eastern and central equatorial Pacific which generates a significant proportion of short-term climate variations) to epidemic vector-borne diseases since identification of such relationships provides the first indication that seasonal climate forecasts might be useful in the development of early warning systems. It has been noted that despite an extensive literature for some diseases, very little research has been conducted in countries with the highest number of child deaths and under-five mortality rates, many of which are in sub-Saharan Africa.

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Widespread episodes of drought, heavy precipitation, and heat waves are predicted to increase as a function of climate change (Field et al. 2011) and such predictions are elaborated on in detail in other chapters in this book. Furthermore, shifting biomes as a result of changes in regional climatologies is considered a primary outcome of global climate change with temperate areas predicted to have the most significant increases in temperature and widespread regional drying being considered one of the more robust predictions for the intertropical regions (IPCC 2007). Noticeable short-term trends in the climate are already being observed in different parts of the world (Omumbo et al. 2011). It is expected that extreme weather events (droughts, floods, heat waves, etc.) that can have devastating socioeconomic, environmental, and health impacts may positively or negatively impact on vector-borne disease transmission. For instance, increases in temperature may increase the development rates of both pathogen and vector, but such warming may be associated with a drier climate where disease vectors are less able to survive and multiply. Thus, the predictability of the impact of climate change on climate-sensitive diseases (including emerging and vector-borne diseases) remains uncertain and is likely to be specific to the particular vector–pathogen–host system. Emerging diseases are most likely to respond positively to climate change as other environmental and social factors provide an increasingly favorable opportunity for emergence. Even if the relation of climate to disease is well understood, there are major challenges associated with the long-term predictability of the climate through climate change scenarios. In a study designed to assess the likely impacts of climate change on development outcomes in Africa, Muller (Muller 2009) noted that the projections of the impacts of global warming on regional climate (especially in Africa) remain largely uncertain and states that “Adaptation strategies should therefore not be motivated by specific impact projections of climate change, but could focus on vulnerabilities instead.” The uncertainty in the climate predictions results from a number of factors; some of the issues raised by Muller are elaborated below: • Future changes in drivers of climate change are themselves uncertain – a circumstance commonly addressed by employing different scenarios on GHG emissions such as the A1, A2, B1, and B2 scenarios (IPCC 2007). • The highly complex climate models only offer a simplistic understanding of the climate system – many aspects of which are poorly understood – particularly in Africa where climate displays strong deviations at the subregional level (e.g., the Sahel), and give little insight to current trends (e.g., the current drying trend in East Africa). • Feedback loops exist between climate change and its drivers that are poorly understood which include site-specific interdependencies among landscape properties, environmental traits, and policy decisions. • Downscaling projections of coarse climate models for assessments of regional and local climate change impacts add to the overall uncertainty in climate change projections. However, even with more appropriate interpretations of

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downscaled models or remotely sensed data, severe challenges will remain, especially in Africa where the climate observation network is a 1/8 of the density of networks found elsewhere (GCOS 2006). Given the above, it is important for the health research and practitioner communities to focus on the utility of information coming from the climate community in solving practical problems at appropriate temporal and spatial scales. Many decision-makers would like to incorporate climate change into their decision process, but the century-long span of typical climate change projections, along with the uncertainty described above, does not fit with their operational outlook which often only spans a few years or at most a decade or two. According to Cane (Cane 2010), while decadal climate predictions are high on the climate science research agenda demand for climate prediction, information at the decadal time scale may well be running ahead of supply. So if climate change scenarios are too uncertain and too long a timescale for practical use and decadal climate forecasts are not available for operational use, what can practitioners expect from the climate community to help manage emerging and vector-borne diseases associated with a changing climate? Of first priority is that climate data and information products must be available and accessible and used appropriately to answer the specific questions of the health community. The importance of this is evidenced by the long-standing debate of the potential for warming in the East African highlands (as a function of climate change) to impact on malaria incidence in the region. A substantial constraint to a robust analysis of climate and malaria for this region has been the very limited access to qualitycontrolled daily observations of surface air temperature from meteorological stations. In 2011, Omumbo and colleagues, working closely with the Kenyan Meteorological Department, analyzed variability and trends for 30 years of qualitycontrolled daily meteorological station data (minimum and maximum temperature and precipitation) obtained from Kericho – the center of the climate–malaria controversy. They not only found significant trends in temperature at this site over the last 30 years but were able to show the relationship of local climate variations with larger climate processes, including tropical sea surface temperatures (SST) and El Nin˜o–Southern Oscillation, Fig. 72.1. New efforts to strengthen country capacities to deliver climate information to user communities is underway. In Ethiopia, Tanzania and Madagascar national meteorological agencies are improving the availability, accessibility and use of quality assured climate products (derived from station and satellite data) for the health community and other sectoral users (Dinku et al., 2011). In addition, an often overlooked aspect of the impact of climate change on emerging and vector-borne diseases, particularly those associated with managed water, may be the unintentional consequences of climate change adaptation. Current adaptation strategies for climate change include widespread use of ponds and dams and evidence is emerging of the potential negative effect. For instance careful studies in Tigray revealed that villagers living near to dams that are built in altitudes lower than 2,000 m are faced with increased risk of malaria incidence. Incidence surveys conducted showed a sevenfold increase in malaria risk for children (Ghebreyesus et al. 1999).

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GOING UP

1.2

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Malaria incidence and temperatures have risen near Kericho in Kenya over the past 30 years; health experts are keen to know whether they are linked.

1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009

Fig. 72.1 Malaria cases and minimum temperature at Kericho, Kenya, compared to global SSTs, tropical LST, and ENSO (Thomson et al. 2011)

Conclusion The global health community has responded to the realization that we live in an increasingly interconnected world (with a rapidly increasing movement of people, pathogens, and vectors across borders). Global health surveillance has also received increasing recognition as a primary source of protection from newly emerging and reemerging threats: infectious diseases, new cycles of pandemics, bioterrorism, as well as climate change (Thomson and Mantilla 2011). The development of an integrated response to multiple threats posed by climate change, vector-borne diseases, and emerging threats seems to be a realistic way forward. To achieve such integration, national governments (and international donors) must increasingly invest in better data quality, methodologies, and tools to provide improved information services across key disciplinary areas (climate, environment, pathogens, people, vectors, livestock, etc.) based on the best that science can offer – with a primary focus on serving national decision-maker needs. Acknowledgments Nature Publishing Group is thanked for permission given to reprint Figure 1.

References Cane M (2010) Climate science: decadal predictions in demand. Nature Geoscience 3:231–232 Dinku T, Hilemariam K et al (2011) Improving availability, access and use of climate information World Meteorological Bulletin 60(2) Feachem R, Phillips A et al (2010) Call to action: priorities for malaria elimination. Lancet 376(9752):1517–1521

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Field CB, Barros V, Stocker TF, Qin D, Dokken DJ, Ebi KL, Mastrandrea MD, Mach KJ, Plattner G-K, Allen SK, Tignor M, Midgley PM (2011) Managing the risks of extreme events and disasters to advance climate change adaptation: summary for policy- makers. A special report of working groups I and II of the Intergovernmental Panel on Climate Change, IPCC, Cambridge University Press, Cambridge, UK and New York, NY, USA, pp 3–21 GCOS (2006) Climate information for development needs – an action plan for Africa, Report and implementation strategy. http://www.wmo.int/pages/prog/gcos/Publications/gcos-108 (ENGLISH).pdf Ghebreyesus TA, Haile M et al (1999) Incidence of malaria among children living near dams in northern Ethiopia: community based incidence survey. Br Med J 319(7211):663–666 IPCC (ed) (2007) Climate change 2007: synthesis report. Contribution of working groups I, II and III to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, New York Jones KE, Patel NG et al (2008) Global trends in emerging infectious diseases. Nature 451:990–993 Kelly-Hope LA, Thomson MC (2008) Climate and infectious disease seasonal forecasts, climatic change, and human health. In: Thomson MC, Herrera RG, Beniston M (eds) Seasonal Forecasts, Climatic Change and Human Health (Advances in Global Change Research). Springer, 31–70 Muller C (2009) Climate change impact on Sub-Saharan Africa: an overview and analysis of scenarios and models. Discussion paper. Deutsches Institut f€ ur Entwicklungspolitik, Bonn Omumbo J, Lyon B et al (2011) Raised temperatures over the Kericho tea estates: revisiting the climate in the East African highlands malaria debate. Malar J 10:12 Rosenberg R, Beard CB (2011) Vector-borne infections. Emerg Infect Dis 17(5):769–770 Thomson MC, Mantilla G (2011) Integrating climate information into surveillance systems for infectious diseases: new opportunities for improved public health outcomes in a changing climate. Emerging persistent infectious diseases: focus on surveillance, Institute on Science for Global Policy (ISGP) Tucsan and Washington DC, USA Thomson MC, Connor SJ et al (2011) Africa needs climate data to fight disease. Nature 471:440–442

Additional Recommended Reading Website of the climate change team of the World Health Organisation http://www.who.int/topics/ climate/en/ Website for the International Research Institute for Climate and Society http://iri.columbia.edu

Food and Water and Climate Change

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Colin D. Butler

Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Struggle to Reduce World Hunger – Emerging from World War II: The Birth of the Food and Agricultural Organization of the United Nations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Emerging from the Specter of Famine: The Green Revolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Population, Food, and Limits to Growth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . How Might Climate Change Impact on Food Security? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Expansion of Agroclimatic Zones to Higher Latitudes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Carbon Fertilization Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Extreme Weather Events and the Risk of Basing Projections on Average Rainfall . . . . . . . . . . Diseases, Pests, and Weeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fisheries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rising Food Prices and Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Modelling Climate Change and Famine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inequality, Vegetarianism, and Food Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Adaptation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions and Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Keywords

Climate change • Food security • Poverty • Agriculture • Crops • Extreme weather events • Drought • Water • Nutrition • Green revolution • Limits to growth • Famine • Food waste

C.D. Butler Faculty of Health, University of Canberra, Canberra, ACT, Australia e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_104, # Springer Science+Business Media Dordrecht 2014

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C.D. Butler “The hungry people of the world [want] bread, and they [are] to be given statistics” John Boyd Orr (1945) (Staples 2003).

Introduction There is a reawakening of the profound challenge of feeding the global population, now forecast to reach eight to nine billion people by 2050 (Godfray et al. 2010). This is the case irrespective of climate change, because other forms of “planetary overload” deepen the challenge of sufficient and sustainable food production. These include declining areas of unused arable land, the need to preserve forests and other ecosystems not currently used to intensively grow food, flattening crop yields for an increasing number of crops in an increasing number of agroclimatic zones, increasing (crop harming) tropospheric ozone, and emerging phosphate scarcity (Butler 2009). In addition, high rates of population growth continue in many regions that are already short of water (Hoekstra et al. 2012). In late 2012, the World Bank warned that if the average global temperature rises by 4 (i.e., three more than it has since about 1850) then profoundly serious adverse consequences are likely to unfold for agricultural production and hence undernutrition. The report recognizes that worsening food security is likely to produce a cascade of unwanted effects, including economic slowdown. In addition, scarcity of resources, especially of food, arable land, and fresh water, is a perennial and potent source of conflict. Enhanced conflict appears a risk especially in developing countries that lack the financial and other means to guarantee adequate food supply in times of need. However, while the scientific literature about agriculture, nutrition, water scarcity, and climate change is rapidly increasing, it remains conservative in at least three key ways. First, there is excessive optimism concerning the probable magnitude of adverse direct agricultural impacts from climate change, even if average global temperature increase can be restricted to only 2 . For example, the 4th report of the Intergovernmental Panel on Climate Change (IPCC) concluded that climate change would generate a modest increase in global food production, provided that global average temperature increase did not exceed 3 (Easterling et al. 2007). This conclusion was based on an exaggeration of the benefits to crops from “carbon fertilization” (see following), a failure to account properly for extreme weather events, and excessive optimism concerning climate change adaptive capacity. These conclusions by the IPCC were consistent with a long tradition of similar findings that also affected the attitude of the Food and Agricultural Organization of the United Nations (FAO) towards climate change (Butler 2009a, b, 2010). The second conservative bias is that there is insufficient recognition, including in the health literature, of the potential for climate change to trigger systemic, interacting, socially propagated adverse effects, on a sufficient scale to endanger civilization, consequences that have been called “tertiary” ecoclimatic effects (Butler and Harley 2010). These effects include conflict, large-scale

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migration, and impaired global governance. Finally, restricting average global temperature rise to 4 is an increasingly distant prospect (Anderson and Bows 2012). Emissions of greenhouse gas emissions continue to rise, despite the economic slowdown. Although there is growing evidence of the energy transition (i.e., a switch from fossil fuels to renewable energy sources), this is still at a far slower rate than is needed. Meantime, according to the most recent report by the World Energy Outlook, global subsidies for fossil fuel exceed that for renewables by a ratio of about 6 to 1. In 2011 these subsidies exceeded 500 billion dollars – about ten times the cleanup costs for Hurricane Sandy, which struck the USA prior to its 2012 Federal election. It is important to recognize, however, that the causes of hunger, famine, undernutrition, and lack of access to clean water are substantially social, rather than climatic, or due to other forms of environmental change. Before a necessarily selected discussion of the literature concerning climate change, food, and water, this chapter will first discuss some of the social and historical aspects of famine and hunger.

The Struggle to Reduce World Hunger – Emerging from World War II: The Birth of the Food and Agricultural Organization of the United Nations The Food and Agricultural Organization of the United Nations (FAO) was conceived and born in the ashes of World War II (Staples 2003). Its founding director was the pioneering nutritionist Dr John Boyd Orr, author of Food Health and Income (1936) and former director of the Rowett Institute, near Aberdeen, Scotland. Orr was a champion of greater nutritional opportunity, across all classes, and had advised the British government on policies which contributed to the unusually fair distribution of food in wartime Britain, which contributed to improved civilian health during that period. In 1927, a Rowett Institute study had shown that the health and growth of poor Scottish children improved if they were given half a pint of milk every day. Orr’s nutritional work attracted the attention of the League of Nations, the United Nations’ forerunner. A few years later, advocates of Orr’s work, active in the league, argued that nutritional supplements could provide a way out of the Great Depression, the dreadful decade that culminated in World War II. The argument was that if governments could commit themselves to properly feeding all of their citizens, it would provide a stimulus to agricultural demand that could help restart the industrial economy. Based partly on Orr’s work, the league also foreshadowed decades of subsequent FAO effort, ongoing until today, by estimating the proportion of people undernourished globally. They concluded two-thirds of the globe’s population was undernourished, a figure that has greatly improved, but little in the last 15 years.

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The first formal meeting to establish the FAO was held in Quebec, Canada, in October 1945, soon after the end of WWII. Orr, despite his prominence, was initially only offered, belatedly, observer status. However, after being invited to speak by the chair, Lester Pearson, Orr was acclaimed by most of the 20 delegates, though not by representatives of the USA or UK, who appeared to consider him impractical and too idealistic. Nevertheless, he was appointed as founding director, though only for 2 years (Staples 2003). As FAO director, Orr continued his idealism, intensely concerned with the links between food insecurity and peace. He sought to minimize a possible return to conflict through a plan centered on achieving “freedom from want,” including of food. He proposed the establishment of a World Food Board, a plan to massively boost global agricultural productivity and to stabilize world prices using an ambitious commodity storage program. But this was opposed by the British Foreign Office and the US State Department. As Staples explains, “Orr’s vision of the postwar world – of how to win the peace – differed markedly from these two powers, which was based on the ideas of free trade and military strength aimed at containing the emerging Soviet block” (Staples 2003). Orr, on finishing his term, declared that he believed that the USA “had missed a great opportunity for taking up the leadership of a prosperous and free world.” As consolation, Orr was awarded the Nobel Peace Prize in 1949. He lived long enough to visit China during its Great Famine (1959–1963) when aged about 80. Alas, along with other dignitaries, including the President of the Royal Society, Orr reportedly accepted at face value Chinese assurances of adequate food and its denial of famine. The story of Orr is reminiscent of analyses such as by Catherine Caulfield and Susan George, of the great British economist John Maynard Keynes, who died, some say prematurely, soon after it became clear that the World Bank would not function in the way that Keynes had hoped. That is, rather than an instrument of global fairness and development, these critics maintained that the primary purpose of the World Bank and the International Monetary Fund was to consolidate American power in the post-war world. However, in recent years, there has been substantially less criticism of the World Bank. Perhaps, under the leadership of Jim Yong Kim, it will truly become a force for global development, as Keynes is reported to have hoped.

Emerging from the Specter of Famine: The Green Revolution Since its independence in 1947, populous India has been an important Asian democracy. Its nonaligned status during the Cold War made it a prized ally for either of the undeclared conflict’s main protagonists. Winning the hearts and minds of the people of the Third World (if not totally eliminating their hunger) had long been part of stated US policy, including through a program established in the 1950s and christened as “food for peace” in 1960 by John F Kennedy, then campaigning for the US Presidency.

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In 1966, in Bihar, one of India’s chronically impoverished, caste-ridden northern states, a famine was emerging. Its ecological causes included drought and flood with limited use of the then just emerging technology of groundwater extraction using tube wells. Its social causes included what the Indian economist Amartya Sen, the 1998 Nobel Prize Laureate in Economics, called a lack of economic “entitlement,” in other words, a maldistribution of the social and political determinants that make possible “effective” demand. It is self-evident that hungry people have a demand for food. However, if such people lack money, credit, food stamps, a patch of land on which to grow food, or some other means to obtain food, then their demand is rendered “ineffective.” Sen, famous for his work on famine, has long argued that organized societies have a responsibility to their population by creating employment or at least by directly providing food supplies during famine (Sen 1981). On hearing of the Bihar famine, senior US State officials, including Walt Rostow, recommended large shipments of American grain as relief. Kennedy’s successor, US President Lyndon Johnson, prevaricated instead, authorizing incremental famine assistance in exchange for evidence that India’s family planning program was being strengthened. In a sense, the USA, by supplying food to India, was enabling the poor of Bihar to exercise effective demand. In the last 5 years of the 1960s, global population growth reached its maximum, at just over two percent per annum. At that time, global fears of approaching famine in many developing countries were widespread, fuelled by writers such as Paul Ehrlich, whose 1968 book The Population Bomb was a major best seller. However, poorly recognized at that time by such activists, food supplies per person were rising steeply as the “Green Revolution” took hold. The term “Green Revolution” was coined in 1968, by William Gaud, former administrator of the US Agency for International Development. Gaud contrasted this “Green” Revolution to a Soviet “Red Revolution” and the then recent Iranian “White Revolution.” He intended it to imply that greater food supply would lower the attraction of Communism. Gaud also linked increased food to development and peace, reflected, for example, by his writing: “Development is the burning obsession of more than half the people in the world. Development as Pope Paul has said, is the new name for peace. Development does matter and it cannot wait.” The Green Revolution, achieved entirely through the ancient technique of selective plant breeding, economies of scale, and the use of fossil fuel (including to enable the manufacture of pesticides), enabled far more food to be grown in a given area, provided there was adequate fertilizer and water. Its dependency on monocultures and fossil fuels, especially for nitrogen, has been criticized by many activists and scholars such as Vandana Shiva and Raj Patel. However, I am unaware of any scholars, including Shiva, who propose how the widespread famines perceived by many as plausible in the 1970s could have been averted without some form of the Green Revolution. In many countries such industrialized agriculture favored large over small farmers and helped to perpetuate inequality. But there are many interlocking reasons for inequality and poverty, and it is overly simplistic to blame an

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agricultural technology, which is operated and controlled by humans. It is possible that when Shiva and other critics denigrate the Green Revolution, their conceptualization includes social as well as technological factors, but if so, this is communicated rather poorly. In any case, it cannot be denied that in the following two decades, the Green Revolution was spectacularly successful in putting the global plow (food supplies) ahead of the stork (human numbers). World hunger also declined, not only as a proportion but also in absolute terms. A few famines occurred from 1970 to 2000, but their scale was modest compared to what had been feared and predicted. The agricultural scientist Norman Borlaug had been instrumental in the Green Revolution. Twenty-one years after Orr, Borlaug was awarded the 1970 Nobel Prize. Given his chance to speak to the future, Borlaug warned: The Green Revolution has won a temporary success in man’s war against hunger and deprivation; it has given man a breathing space. If fully implemented, the revolution can provide sufficient food for sustenance during the next three decades. But the frightening power of human reproduction must also be curbed; otherwise the successes of The Green Revolution will be ephemeral only. (Tribe 1994)

This warning was prescient. US Presidents from Eisenhower to Carter had recognized that high population growth and global food security could not be taken for granted (Butler 2004). They not only favored policies that supported the Green Revolution but also supported policies (either directly or indirectly) that slowed global population growth, not only in India, as the example of Bihar discussed above reveals.

Population, Food, and Limits to Growth However, in 1984, US President Ronald Reagan explicitly declared that the importance of human population size had been “vastly exaggerated.” Since then, the stork has no longer fallen behind the plow. While many food experts, including the FAO and the head of the World Food Programme, Josette Sheeran, claim that food production per person is now at a record high, reality is far more problematic. Already, close to 40 % of US maize is diverted to biofuels. Though about a third of its energy value is recovered and fed to animals, mainly cattle as “distiller’s grain,” this quantity of corn could feed millions of people if fed directly to them. If food lost from the human diet because of diversion to biofuels (not only from maize but also from other important crops such as sugar cane and palm oil) is subtracted, the residual amount of food per person is stable or declining. Compounding this is the problem of the increasing quantity of food edible to humans that is diverted to feed livestock, including farmed fish. At the same time, the global population continues to rise by at least 70 million per annum, an annual increment probably exceeding that in 1968, when global population increase peaked as a percentage.

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Central to these developing problems is a slowly reawakening of concern about limits to growth (Meadows, Meadows et al. 1972). Evidence of this is most obviously shown by the persistently high price of energy, despite the global economic slowdown, now in its fifth year, and despite the discovery of increased ways to recover shale oil, especially in the USA. These scarcities are deepened by a still growing human population, mainly in low-income countries (Royal Society 2012). These worsening interacting problems will increasingly interact with climate change and global food production. Modern agriculture is heavily dependent upon cheap and abundant energy, vital for transport, for the manufacture of nitrogenous fertilizer and pesticides (Neff et al. 2011). Perversely, the poorest populations in low-income countries who appear most vulnerable to the harm from climate change and other global environmental challenges contribute little on a per capita basis to resource demand, but are particularly vulnerable due to their limited human and institutional capacity. From about 1970 until about 2000, famines were mercifully rare, though they did occur in Bangladesh in 1974 and in Ethiopia a decade late. However, in the last 5 years, since the first food price spike in 2008, several significant famines have occurred, mostly in North Africa. Countries affected include Kenya, Somalia, Sudan, and Niger. The Islamist group Al Shabaab, who exert much control over modern Somalia, have greatly worsened the human toll of the Somali famine by such tactics as intimidating, kidnapping, and killing famine relief workers. Yet, in nearby Somaliland, a quasi-independent breakaway nation, little if any famine occurred at all, even though it too has experienced severe drought. An Asian country, North Korea, has experienced severe food insecurity and frank starvation for two decades and must be added to this list of famine-affected nations. There appears to be a discernable increased trend in famine and food insecurity, in part caused by higher food prices and poorer governance. To what extent, if any, has climate change contributed?

How Might Climate Change Impact on Food Security? The growing of crops or pasture requires soil, nutrients (including phosphorus and nitrogen), water, and a suitable climate. Agriculture depends on tradition, culture, expertise, technology, and labor. The climate influences the temperature (maximum, minimum, and pattern), rainfall, humidity, and wind patterns; it also influences pests and diseases of plants and animals. Solar radiation is also important and is influenced by factors including latitude, altitude, clouds, aerosols, and tropospheric ozone. Carbon dioxide is also essential for photosynthesis. Food security depends on numerous non-agricultural factors, some of which are outlined above. Many of these elements can be influenced by climate change, such as infrastructure and human health. It is logical that the set of social and environmental factors that affect agriculture can be either optimal or suboptimal (albeit optimality is likely to be along a spectrum rather than a single point) and that climate change can change the suitability of

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agriculture in three ways, an improvement, no change, or a decline. On reflection, it is reasonable to conclude that agricultural conditions in areas that have for a long time been densely populated (e.g., India, China, Southeast Asia) are excellent, though probably not optimal, due to factors such as imperfect soil or water. But there is broad consensus that in most tropical areas, climate change is unlikely to significantly improve growing conditions in such areas, and it could well worsen them. Of central importance is whether new areas made suitable for cultivation by climate change (such as at higher altitudes or latitudes) will fully compensate for areas forecast to decline in productivity. From first principles, this is unlikely. However, many non-climatic determinants of food security greatly complicate the detection and attribution of climate change impacts. In general, especially in nonindustrialized countries, crop yields (the quantity of food that can be grown in a given area) have improved substantially, due to improved seeds, more fertilizer, and irrigation – in short the application of knowledge and technology. Of concern, the rate of this improvement has greatly slowed. There is, nevertheless, considerable potential for major improvement in crop yields in Africa (Ejeta 2010). But most of this potential is not being realized, and rising prices of energy and phosphate steepen the task. So far, the greatest rate of climate change has been at mid- and especially high latitudes, such as the Arctic. However, warming is also well documented in the tropics, including sites with excellent data, such as at the International Rice Research Institute in the Philippines (Peng et al. 2004). With less confidence, significant changes to rainfall have also been observed (Min et al. 2011), including in India, a vital food-producing nation (Auffhammer et al. 2012). Complex effects from climate change upon irrigation are also likely, not only from changed rainfall but also from accelerated glacial melting and reduced summer river flow, including many of the great rivers springing from central Asia, the so-called Third Pole. Extreme heat can be lethal to crops, but lesser degrees of heat can also be harmful, especially if at night (Peng et al. 2004). Yields for three of the most important cereals – rice (Peng et al. 2004), maize (Lobell et al. 2011), and wheat (Ortiz et al. 2008; Prasad et al. 2008) – have all been shown to respond adversely to excessive heat. There is also increasing evidence that in tropical regions, increased temperature is depressing crop growth on large scales, including those of rice (Auffhammer et al. 2012), wheat, and corn (Lobell et al. 2011). However, in contrast, at least for the earlier period of 1952–1992, Nicholls found that warming significantly increased Australian wheat yields (independent of rainfall, which was not analyzed) perhaps because of a reduction in frost frequency (Nicholls 1997). However, in the following two decades in Australia, the improvement in average wheat yields seems to have lessened, due especially to the increased dryness in the Australian wheat belt, which has also been linked to climate change. Australia is normally a major exporter of grain (due to its low population in comparison to its arable area) but in 2003 it was a large net importer of grain. Since 1992, therefore, the increase in wheat yield in Australia is likely to have flattened.

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On the other hand, an analysis has detected no harm globally (though not regionally), as yet, to the harvest of rice and soy due to climate change (Lobell et al. 2011). A possible explanation for this is that rice yields have increased at extratropical latitudes in ways that to date compensate for the decrease in rice yield increase reported from India and which are possibly occurring elsewhere. It is important to stress that the magnitude of detected decline in agricultural production due to increasing temperatures and changes in rainfall is still low compared to the increase in harvests due to improved farming knowledge and technology. It is also trivial compared to the amount of food fed to livestock, used for biofuels, consumed beyond baseline needs by the overnourished, and wasted in other ways.

Expansion of Agroclimatic Zones to Higher Latitudes The impact of climate change on food security has been modelled for over two decades (Butler 2009b). A consistent conclusion over most of this period has been the prediction that climate change will bring benefits and harms to agriculture and food security, especially in the short to medium term (e.g., to 2100). This is consistent with the argument made above. Beyond this, however, the consensus in the 1990s and perhaps even the first decade of this century was that the winners would approximate the losers, in part because of the assumption of a strong “carbon fertilization effect” (see the following) (Butler 2009b). Most of the agricultural benefits of climate change were initially predicted to flow to developed, extratropical countries (Butler 2009a). Until 2003, there is little evidence that the FAO considered climate change as a serious threat to food security, when it finally highlighted climate change at the 29th session of the FAO Committee on World Food Security (Butler 2009a). Warmer weather at higher latitudes and altitudes has long been predicted to expand potentially arable areas, including in some nations with enormous quantities of sparsely populated areas, especially in Russia, Canada, and Scandinavia. In the southern hemisphere, sugarcane production in Brazil is predicted to shift towards the south, as may the coffee crop. There is good evidence that climate change has contributed to the increased yield of potatoes observed in Scotland since 1960. However, as mentioned above, the key issue is whether such new areas suitable for cultivation fully compensate for areas which are forecast to decline in productivity. This point was stressed in a critical letter to Nature in 1994 (Pittock et al. 1994). Much of the soil that may become newly subjected to agriculture is likely to be acidic, or in other ways poor, such as in the boreal forests of Russia. Soil improvement will require large fossil-fuel intensive investments, including that of fertilizer. It also does not automatically follow that rainfall or groundwater will be adequate. Additionally, powerful economic factors will be needed to trigger the needed investment. If, as seems all too plausible, parts of South Asia or sub-Saharan Africa are impoverished by climate change, then their populations may not command the

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effective demand to stimulate a massive expansion of crops at northerly latitudes. In South Asia, most agroclimatic models forecast cereal declines by 2080, some by as much as 22 % (Tubiello and Fischer 2007). Lastly, agriculture at such higher latitudes is likely to be restricted to a single annual crop, due to lack of sunlight in winter. It thus does not automatically follow that increased crop production from high latitudes will easily or fully compensate for the forecast reduction in crops elsewhere. Agroclimatic models beyond 2100 are rare, if they exist at all. If they do, the intrusion of sea level rise, likely by then to be at least a meter (Hansen 2007) on fertile low-lying shorelines, including many parts of coastal Bangladesh and deltas such as the Mekong and Nile, combined with increased extreme weather effects, seems likely to result in overwhelmingly negative effects on food production, as the 2012 World Bank report warns. Many of these deltas are sinking at a greater rate than the sea is rising (Syvitski et al. 2009). Sea level rise is excluded from agroclimatic models.

The Carbon Fertilization Effect The harm of climate change has long been predicted to be partially offset by the carbon fertilization effect (CFE). The CFE refers to evidence and theory that elevated levels of carbon dioxide (CO2) will promote plant growth. There is strong consensus that the CFE is valid for “C3” plants, including wheat, rice, and soy, but more recent studies based on free air carbon enrichment (FACE) methods (Long et al. 2006) have shown that it far is less potent for the other kind of plants, called C4. Some C4 crops are also vital for global food security, particularly maize, sorghum, and sugar cane. The CFE is also altered by the availability of water (probably the CFE is comparatively stronger in droughts) and nitrogen. In the future, lower amounts of soil nitrogen, due to higher energy prices and hence more expensive fertilizer, might also impede the full benefit of the CFE. There is also uncertainty about the agricultural effect of other gases such as tropospheric ozone (O3) in combination with CO2. Ozone precursors emitted by vehicles, coal- and gas-fuelled power stations and the burning of biomass reduce photosynthesis and lower crop quality (including protein content) and yields. The harmful effect of ozone on crop production probably far exceeds that from climate change, particularly harming wheat, soybean, maize, and rice, especially in Asia. Finally, increased CO2 may damage some crops, including the important staple cassava. It may also favor some important insect pests.

Extreme Weather Events and the Risk of Basing Projections on Average Rainfall The likely effect of climate change upon crops, livestock, and fisheries cannot be estimated simply using models based on average growing season temperature or

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250 High oil price, Russian, Ukrainian and U.S. extreme events?

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Oil price, speculation, rice panic

Index 150

European heatwave effect?

100

50

0 1990

Food Price Index

1995

Cereals Price Index

2000

2005

2010

Fig. 73.1 Food price index 1990–2012. Since 2000 there have been two pronounced and one minor peak in food prices. The first one (2003) may have been in part driven by the European heat wave of that year, which depressed European grain production. The second, in 2008, was driven by speculation and the very high price of energy. However, it is plausible that the third peak – really a plateau, already lasting almost 2 years – has mainly been driven by extreme weather events themselves which were likely made worse by climate change. The increasing diversion of edible crops to biofuels is a background factor

rainfall, though these factors are a crucial starting point. Also long recognized and important is whether the distribution or intensity of rain or temperature alters. Increased rainfall intensity combined with longer dry spells could maintain average rainfall, yet be far less favorable for agriculture, especially for crops (Rosenzweig et al. 2002). Climate extremes also harm the welfare and reduce the productivity of livestock. Climate change has for many years been predicted to alter the intensity and distribution of rainfall. Recent evidence suggests that rainfall models are conservative and essentially biased towards optimism. Limited observational data also suggest that moist regions are becoming wetter and dry regions drier (Min et al. 2011), although this has been recently disputed (Sheffield et al. 2012). The current drought in much of the USA (2011 to present) has already significantly depressed production of corn and soybeans and has undoubtedly contributed to the elevation of world food prices observed since late 2010 (see below, also see Fig. 73.1). However, while this North American drought is too recent for much analysis in the peer-reviewed literature to be yet available, it is consistent with climate

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change, not least, as the record dryness is associated with record temperatures. An increasing number of climate scientists are now arguing that all extreme weather events should be considered to be partly worsened by climate change (Rahmstorf and Coumou 2011; Hansen et al. 2012). If this proposition was to be accepted then it would follow that climate change is already having a significant adverse effect on crop production, food prices, and hence nutrition and health. The most important forms of extreme weather events (EWEs) appear to be heat waves, droughts, floods, and storms. Excessive heat also affects agricultural workers, and heat waves during critical periods of intense labor, such as harvest, is likely to lower yields (Kjellstrom 2009). Altered precipitation patterns are also likely to lead to increased agricultural variability, reducing livelihood security for landless agricultural laborers and thus worsening food security. Such vulnerable populations face a double jeopardy less income in conditions of tightened food supply at increased prices. As mentioned, there is growing evidence that EWEs are changing, albeit in complex ways. For example, Hurricane Sandy was only a category one storm as it approached the US coast. The traditional Sapphire-Simpson hurricane scale does not fully capture Sandy’s immense power. In 2009 the slow-moving category 3 Typhoon Morakot devastated agricultural regions in Taiwan; it too had a greater impact than indicated solely by its wind speed. Other events, such as the severe drought in the Indian states of Karnataka and Andhra Pradesh in 2009 that was broken by rains judged as the greatest in a century (Butler 2010), are also difficult to capture in databases. The floods displaced at least one million people. A paucity of high-quality agricultural, health, and meteorological data, especially in low-income areas, makes the attribution and measurement of adverse agricultural effects due to climate change very difficult. Also to be considered are changed patterns of winds, hailstorms, forest fires, and other phenomena, such as the trajectory and frequency of cyclones and hurricanes. Saline intrusion is already a problem in coastal regions of Bangladesh and some low-lying islands. There are other large-scale risks, such as a weakening in the Indian monsoon. Intensification of the El Nin˜o-Southern Oscillation and other ocean currents and atmospheric oscillations may also occur. These risks are currently excluded from agroclimatic models. However, a recent paper has found that monsoon rainfall in India has become less frequent but more intense in India in recent decades, slowing rice yield increase by 1.7 % in rain-fed areas, with drought being far more important than more intense precipitation. These workers also concluded that rice yield growth was further depressed by warmer nights and a reduction of rainfall at the end of the growing season (Auffhammer et al. 2012).

Diseases, Pests, and Weeds Other likely effects of climate change upon agriculture include altered crop and animal diseases, such as the expansion of the midge-transmitted viral disease,

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bluetongue, a growing problem for livestock in Europe. Epidemics of the livestock disease, Rift Valley fever in East Africa, are associated with increased rainfall and flooding, the frequency and severity of which may change due to climate change. Milder winters are predicted to expand the range of some important pests, such as the corn earworm. However, climate change may improve the resistance of some crops to diseases. Overall, there is no consensus of the net impact of climate change upon crop diseases. Just as climate change is likely to alter the distribution of food crops, it will also probably change the location of important weed species. In some cases, the CFE will disproportionately favor weed root growth, and this may reduce herbicide efficacy.

Fisheries A detailed analysis of the impacts of climate change on fisheries (including aquaculture) is beyond the scope of this chapter. In brief, however, climate change is also predicted to have complex effects on fisheries, including changing the temperature and the pattern of ocean currents, thus redistributing marine productivity, especially to higher latitudes. A declining trend in the global phytoplankton concentration since 1899, in eight out of ten ocean regions, has been linked with warming sea surface temperatures. Increasing ocean acidity and climate changeassociated deoxygenated zones will also harm future marine productivity. Furthermore, ocean acidification associated with increased carbon dioxide concentrations interferes with the development of a wide range of aquatic species. It is already harming coral reef systems and further stressing fish stocks already in decline. As with crops, climate change is thought to increase fishery production in some areas but lower it in others. Increased acidification will harm invertebrate species, damaging corals, which provide essential habitat for many fished species. This will disproportionately affect many poor and vulnerable populations, including in small-island states, and parts of western African and some tropical Asian countries. Furthermore, warmer temperatures due to climate change have been attributed to reducing nutrient mixing and fishery productivity in Lake Tanganyika, in Africa.

Rising Food Prices and Climate Change For centuries, the long-term trend of food prices has been in decline. Since at least 1990, the FAO has calculated an index of food prices (see Fig. 73.1). The increase in this index in 2008 surprised many observers, even though it is consistent with the warnings given by Borlaug and the World Scientists’ Warning to Humanity, signed in 1992. The most plausible proximate cause of the food price increase in 2008 is that year’s rise in energy prices, especially oil, reached over US$140 per barrel. Higher energy prices also increased the price of fertilizer. However, in December 2010, the

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Table 73.1 Extreme weather events in 2010 and their effect on crop production in three nations. The intense heat wave in Russia and Ukraine and the Pakistani floods depressed wheat and rice both domestically and globally. The fall in Pakistani rice production in 2010 was similar to that of the Russian drop in wheat, but had less effect on global production. This is because, in most years, Russia and Ukraine grow about 12 % of global wheat, while only 2 % of global rice is grown in Pakistan

2010 (as % of 2009)

Wheat Russia 67 %

Ukraine 81 %

Global 95 %

Per capita 94 %

Rice Pakistan 70 %

Global 98 %

Per capita 97 %

indexed price of food approached the 2008 peak is and has remained unusually high. Yet the price of energy was about 60 % less than its 2008 peak. As yet, few published studies have analyzed the cause for this second price rise. Two factors seem important, in addition to fairly energy prices. One is the apparently relentless rise in the fraction of global food crops used for biofuels, which itself is largely in response to the growing scarcity of easily recoverable crude oil, essential for transport using current technology. But the second reason may be a nonlinear response to climate change, particularly due to the apparent increase in extreme weather events which have occurred in recent years. The most notable of these were the Russian and Ukrainian heat wave of 2010 and the Pakistani flood in the same year. The Russian heat wave was especially significant because it affected the traditional “breadbowl” of the former Soviet Union. It led to a 66 % increase in the global price of wheat within 2 months and a lesser rise in other grain prices. The 2010 floods in Pakistan did not exert a very large death toll but displaced over 20 million people, some of them for months. However, the Pakistani flood and the Russian heat wave in the same year contributed to a decline in per capita global grain production in 2010 (see Table 73.1). Previously, the extraordinary European heat wave of 2003 also lowered crop yields in several European countries. Food prices did rise slightly in 2003, but from a lower base. Global food prices have multifactorial causes, including the price of energy, the size of stocks, and the percentage used for biofuels. Speculation can also distort food prices, as can bans on food exports, driven by national food security concerns, whether or not in association with extreme weather events. There is debate as to whether climate change contributed to the Russian heat wave. However, there is increasing support for the proposition that the burden of evidence concerning the contribution of climate changes to such events should switch. That is, some climate scientists are now arguing that climate change should be accepted as a contributor to these extreme events until proved otherwise (Trenberth 2011). The recent Somali famine may also be causally related to climate change. In the last three decades, the Indian Ocean has warmed especially fast, in association with increased precipitation over the tropical Indian Ocean. Walker and Funk claim that since 1980, this has suppressed convection over tropical eastern Africa, decreasing precipitation during the “long-rain” season of March to June. Unfortunately, their attempts to alert Somali

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Table 73.2 Since 2003, a number of extreme weather events have occurred which have reduced crop production. At present, there is no comprehensive dataset of “extreme agricultural events,” and the apparent trend in the severity of these events (as evident in this table) in part is likely to reflect recall and reporting bias. Nevertheless, other factors (e.g., declining crop yield growth, falling soil fertility, competition from feed and biofuels, and ongoing population growth) mean that any reduction in crop growth due to extreme weather events is increasingly likely to have an adverse effect on global food prices, per capita global food production, and thus global health Event Heat wave Fires and heat Typhoon Heat wave

Year 2003 2009 2009 2010

Flood Flood Drought Heat and drought

2010 2011 2011 2011–2012

Location Europe Australia Taiwan Russia and Ukraine Pakistan Thailand NE Africa USA

Drought

2012

Niger

Significant crop effect? Yes Yes Yes Yes (significant global price rise at time) Yes Likely (no FAO data yet) Yes (famine) Likely (no FAO data yet), significant grain price rise, June 2012 Yes (famine)

authorities to the likelihood of famine were unsuccessful, but may have been benefitted other better-governed parts of the Horn of Africa, including Somaliland and Ethiopia. Crop production is vulnerable to many factors associated with climate change, apart from extreme weather events such as those listed in Table 73.2.

Modelling Climate Change and Famine The plethora of effects of climate change upon global and regional agriculture create a formidable modelling challenge. Models omit many factors, both climatic and non-climatic, that are likely to impact on future food production. There are several reasons for these omissions that result in agroclimatic models that are excessively simple and biased towards the optimistic (Butler 2010; Gornall et al. 2010). Current agroclimatic models poorly incorporate increased extremes, including rainfall intensity, sea level rise, saline intrusion, glacial melting and the possibilities of monsoon weakening, and intensification of the El Nin˜o-Southern Oscillation and other ocean currents and atmospheric oscillations. They also omit the effect of climate change on mycotoxins, and crop and animal diseases (Butler 2010). In summary, the decline detected in food production ascribed to climate change is already likely to be understated and that of future climate change even more so. Most models are designed to only consider the impact of climate change upon future agricultural food supplies, rather than model health impact, a task which is even more complex and difficult. The capacity of ingested food to provide adequate nutrition is influenced by factors other than food ingestion. For example, the level of physical activity (not just paid work, but unpaid labor such as carting water,

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sometimes over hilly terrain) and states of health and disease that diminish appetite, lower nutrient absorption, and increase metabolic rates all alter demands and utilization of food. There are several reasons for the weakness in modelling, other than its complexity. The sheer number of such effects presents a daunting, perhaps intractable computational challenge. Even if surmounted, such models are likely to be effectively impenetrable to others and thus regarded with suspicion. In addition, few if any agroclimatic modelling teams are likely to feel empowered or motivated to incorporate a comprehensive list of extra-climatic factors (e.g., rates of parasitic infection). Furthermore, many of the climatic factors, such as a sea level rise of 50 cm, or a weakening of the Indian monsoon, are either decades away or highly uncertain. It is thus not surprising that models have largely been restricted to average temperature, average rainfall, and the CFE. But while no models incorporate most of these other effects, it can be concluded that aggregates, both classes of omitted factors, are likely to be negative, particularly from the second half of this century. It is also stressed that models, despite their flaws, consistently forecast a decline in agricultural productivity in hot regions.

Inequality, Vegetarianism, and Food Waste A complete global sharing of food resources, with the total abandonment of feeding grain and other crops such as soy as feed to livestock, would considerably lessen world famine without any Green Revolution, as was advocated in the classic book Diet for a Small Planet. However, there is little support for this. Vegetarian diets can be healthy for many people, but are neither culturally preferred nor ecologically possible in many places. Many traditional cultures rely on pastoralism, rather than intensive livestock raising. In pastoral systems animals eat grass and scraps, not grain, and thus add to total food supply by converting cellulose, indigestible to humans, to animal products, including meat, milk, wool, and leather. But as many as a billion people eat more animal products, especially meat, than they need. Lowering the meat consumption (especially of red meat from “digastrics,” methane-emitting cattle, sheep, and goats) of this billion people will improve their health and slow climate change. This is because meat production, especially from farmed animals, is a significant contributor to greenhouse gas production (McMichael et al. 2007). But a fully vegetarian diet is unlikely to be physiologically adequate for many people. Genetic variations such as hemochromatosis are advantageous for people with limited iron intake (Naugler 2008). Those lacking this or similar genes are likely to be at a disadvantage if forced to be vegetarian. Arguments for a completely equal distribution of global food resources are also problematic. It is clear that excessive inequality cannot be indefinitely sustained in either human society or even many animal groups (de Waal 2009). However, all human and most animal groups are characterized by many forms of inequality, such as of power, experience, strength, and ability. The complete abolition of human

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inequality on a global scale in the interest of maximizing food supplies seems utopian and unrealistic, though the reduction of such inequality is desirable and partly achievable. Treatment of parasitic conditions among the poor, such as hookworm, schistosomiasis, and malaria, will greatly improve nutrition, even without additional food production. Food fed to people suffering from chronic diarrhea and other illness can also be better utilized by better health care, adequate sanitation, and clean water. Much food is also wasted due to pests and poor storage, whether preharvest (such as lost on the field), postharvest (e.g., eaten by rodents), or post-processing (e.g., thrown out from supermarkets or wasted after purchase). The custom of eating offal has vanished among most affluent populations. In rich countries enormous quantities of edible food are thrown out of supermarkets, restaurants, and people’s homes (Parfitt et al. 2010). Reducing this waste will extend food supplies that seem likely to be increasingly scarce.

Adaptation There is much hope and some evidence that adaptation to climate change will ensure sufficient crop production and hence food security. Farmers are adaptable and naturally keen to remain profitable and viable. Where there is good evidence and adequate communication, progressive farmers (of whom there are many) will adopt new crops and cultivars, such as salt-, heat-, and droughtresistant strains. Some crops may be able to bred that are particularly responsive to increased CO2 concentrations. In some places, longer growing seasons may allow double cropping. Farmers in some regions are already adapting to climate change by altering sowing times and farming practices such as tilling. The use of irrigation and extraction of groundwater is important for adaptation in some regions, as is more effective water harvesting (i.e., capturing rainwater for later use). Migration can also be conceptualized as an adaptation strategy, such as from heat- and drought- affected India to a potentially more habitable and fertile Siberia. In reality, the effectiveness of this is likely to be restricted by xenophobia in receiving nations, but it is conceivable that some newly fertile areas could employ increasing numbers of “guest workers” on restrictive visas. Over time, this could become normalized. However, it is hard to imagine this strategy being successful if hundreds of millions of people seek to migrate. Rural to urban migration is a worldwide phenomenon, increasing unplanned slums. If food prices continue to rise, such slums may become traps of chronic deprivation, infectious, and other forms of disease associated with undernutrition, rather than successful forms of adaptation. Beyond thresholds, adaptations are likely to become reduced in their effectiveness. Farmer adaptation is also likely to be made more difficult if rural impoverishment increases in stressed areas, due to climate change and other factors such as increased energy costs. If, as seems increasingly likely, the world experiences

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warming beyond 2 then factors such as sea level rise and heat waves in the low latitudes could overwhelm adaptive capacity. The hope of future adaptation should not be seen as a reason to not engage in vigorous mitigation.

Conclusions and Recommendation Decarbonizing the global energy system is necessary and urgent to slow climate change. The task has commenced but needs enormously more intensity and vigor. While adaptation is essential it is the view of this author that excessive faith is being given to it, at the expense of prevention (mitigation). Health workers would be wary of any strategy to cope with epidemics that are based on treatment rather than prevention. Although the Green Revolution did significantly improve crop yields, its heyday is well past. For two decades agricultural technologists have promoted the potential of genetic manipulation to effectively trigger a new agricultural revolution. While some progress has been made in this direction (possibly with adverse health effects), the scale and pace of these advances are far slower than the challenge of climate change and other forms of limits to growth require. Without unforeseen technological breakthroughs, the problem of climate change will be increasingly worsened by the high price of energy and phosphorus. Low-income populations cannot look for rescue by high-income populations. Low-income countries need better and fairer governance, more education, and to accelerate their demographic transitions in order to lower their vulnerability (Bryant et al. 2009). High-income countries need to alter their current emphasis on adaptation to a much stronger focus on greenhouse gas mitigation. Instead, they must awaken to the urgency posed by climate change, limits to growth and their interaction with global security. Alliances perhaps may strengthen between philanthropists and activists in developing countries, in order to facilitate technological “leapfrogging” and to improve the other social and environmental factors needed to promote resilience, well-being, and the endurance of global civilization. Finally, there is an urgent need to need to develop agroclimatic models which are more realistic. Such models should try to better integrate knowledge from the social and physical sciences and to also incorporate a range of extra-climatic factors, such as soil quality and the likely price of fertilizer. Increased famines contributed to by climate change appear likely. If left unaddressed, climate change threatens increasingly profound and adverse effects to food security and hence health and nutrition. Rising food prices stimulate social unrest and can contribute to the overthrow of governments. Conflict can easily occur due to scarcity of raw materials including food and fertile soil. Overfed people, especially if consuming animal products raised on grain and soy, can and should reduce their consumption of these products. There is perennial hope of a new agricultural revolution, to be fostered by further investment. But too much hope is invested in this strategy, other than

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in Africa, where much can be done to bring the first Green Revolution (Ejeta 2010). But even more important to development and nutrition in developing countries is the need to alter the determinants of fertility, in ways that will increase child survival, the demand for education, and lower population growth.

References Anderson K, Bows A (2012) A new paradigm for climate change. Nat Clim Change 2(9):639–640 Auffhammer M, Ramanathan V et al (2012) Climate change, the monsoon, and rice yield in India. Clim Change 111:1–14 Bryant L, Carver L et al (2009) Climate change and family planning: least developed countries define the agenda. Bull World Health Organ 87:852–857 Butler CD (2004) Human carrying capacity and human health. Public Libr Sci Med 1(3):192–194 Butler CD (2009a) Food security in the Asia-Pacific: Malthus, limits and environmental challenges. Asia Pac J Clin Nutr 18(4):577–584 Butler CD (2009b) Food security in the Asia-Pacific: climate change, phosphorus, ozone and other environmental challenges. Asia Pac J Clin Nutr 18(4):590–597 Butler CD (2010) Climate change, crop yields, and the future. SCN News 38:18–25 Butler CD, Harley D (2010) Primary, secondary and tertiary effects of the eco-climate crisis: the medical response. Postgrad Med J 86:230–234 de Waal F (2009) The age of empathy. Harmony Books, New York Easterling WP, Aggarwal et al (2007) Food, fibre and forest products. In: Parry M, Canziani O, Palutikof J, van der Linden P, Hanson C (eds) Climate change 2007: impacts, adaptation and vulnerability. Contribution of Working group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK, pp 273–313 Ejeta G (2010) African Green Revolution needn’t be a mirage. Science 327:831–832 Godfray HCJ, Beddington JR et al (2010) Food security: the challenge of feeding 9 billion people. Science 327:812–818 Gornall J, Betts R et al (2010) Implications of climate change for agricultural productivity in the early twenty-first century. Philos Trans R Soc B 365:2973–2989 Hansen J (2007) Scientific reticence and sea level rise. Environ Res Lett 2, 024002, 6 pp Hansen J, Sato M et al (2012) Perception of climate change. Proc Natl Acad Sci 109:14726–14727 Hoekstra AY, Mekonnen MM et al (2012) Global monthly water scarcity: blue water footprints versus blue water availability. PLoS One 7(2):e32688 Kjellstrom T (2009) Climate change, direct heat exposure, health and well-being in low and middle-income countries. Glob Health Action 2 Lobell DB, Ba¨nziger M et al (2011a) Nonlinear heat effects on African maize as evidenced by historical yield trials. Nat Clim Change 1:42–45 Lobell DB, Schlenker W et al (2011b) Climate trends and global crop production since 1980. Science 333:616–620 Long SP, Ainsworth EA et al (2006) Food for thought: lower-than-expected crop yield stimulation with rising CO2 concentrations. Science 312:1918–1921 McMichael AJ, Powles J et al (2007) Food, livestock production, energy, climate change and health. Lancet 370:1253–1263 Meadows D, Meadows D et al (1972) The limits to growth. Universe books, New York Min S-K, Zhang X et al (2011) Human contribution to more-intense precipitation extremes. Nature 470:378–381 Naugler C (2008) Hemochromatosis: a Neolithic adaptation to cereal grain diets. Med Hypotheses 70(3):691–692

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Neff RA, Parker CL et al (2011) Peak oil, food systems, and public health. Am J Public Health 101:1587–1597 Nicholls N (1997) Increased Australian wheat yield due to recent climate trends. Nature 391:484–485 Ortiz R, Sayre KD et al (2008) Climate change: can wheat beat the heat? Agr Ecosyst Environ 126(1–2):46–58 Parfitt J, Barthel M et al (2010) Food waste within food supply chains: quantification and potential for change to 2050. Philos Trans R Soc B Biol Sci 365(1554):3065–3081 Peng S, Huang J et al (2004) Rice yields decline with higher night temperature from global warming. Proc Natl Acad Sci U S A 101(27):9971–9975 Pittock AB, Whett P et al (1994) Climate and food supply. Nature 371:25 Prasad P, Pisipati S et al (2008) Impact of night-time temperature on physiology and growth of spring wheat. Crop Sci 48:2372–2380 Rahmstorf S, Coumou D (2011) Increase of extreme events in a warming world. Proc Natl Acad Sci USA 108(42) Rosenzweig C, Tubiello FN et al (2002) Increased crop damage in the US from excess precipitation under climate change. Glob Environ Chang 12(3):197–202 Royal Society (2012) People and planet Sen AK (1981) Poverty and famines: an essay on entitlement and deprivation. Clarendon Press, Oxford/New Delhi Sheffield J, Wood EF et al (2012) Little change in global drought over the past 60 years. Nature 491(7424):435–438 Staples ALS (2003) To win the peace: The Food and Agriculture Organization, Sir John Boyd Orr, and the World Food Board proposals. Peace Change 28(4):495–523 Syvitski JPM, Kettner AJ et al (2009) Sinking deltas due to human activities. Nat Geosci 2(10):681–686 Trenberth KE (2011) Attribution of climate variations and trends to human influences and natural variability. WIREs Clim Change 2(6):925–930 Tribe D (1994) Feeding and greening the world. CAB International in association with the Crawford Fund for International Agricultural Research, Wallingford Tubiello FN, Fischer G (2007) Reducing climate change impacts on agriculture: global and regional effects of mitigation, 2000–2080. Technol Forecast Soc Change 74:1030–1056

National and Global Monitoring and Surveillance Systems for the Health Risks of Global Change

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Kristie Ebi

Contents Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring and Surveillance Data Needs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Networks for Linking Health, Meteorological, and Other Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Indicators of the Health Risks of Global Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Iterative Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cross-References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

Understanding and managing the challenges of global change means that current monitoring and surveillance programs need to be modified to collect and analyze data and communicate information to understand the burden and geographic distribution of current and possible future risks of global change, the options to manage these risks, and the effectiveness of implemented strategies, policies, and measures. These modifications include integrating data from a wide range of disciplines, collecting new data to fill knowledge gaps, and ensuring an iterative process of data collection and analysis as baselines and risks continue to change.

K. Ebi ClimAdapt, LLC, Los Altos, CA, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_105, # Springer Science+Business Media Dordrecht 2014

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Keywords

Global change • Adaptation • Weather and climate extremes • Monitoring • Surveillance • Public health prevention

Definitions Monitoring and surveillance activities collect information on “all aspects of the occurrence and spread of disease that are pertinent to effective control” (Last 2001).

Introduction Monitoring and surveillance are core activities of public health that systematically collect, analyze, and interpret information on cases of and trends in the occurrence and spread of adverse health outcomes. These activities also collect information on relevant risk factors, including behavioral, socioeconomic, environmental, and occupational. This information is the basis for actions taken by local, regional, national, and global public health and health-care organizations and institutions to protect and improve the health of the populations they serve. Effective monitoring of the health risks of global change needs to include data, information, and knowledge on the interacting factors that create the health risks of global change (IPCC 2012): • The hazards associated with global changes, such as changes in the frequency, intensity, duration, and spatial extent of extreme weather and climate events, or changes in marine productivity due to nitrogen runoff. • Who or what is exposed to the hazard. This considers the communities, ecosystems, and geographic regions that are or could be exposed, such as urban informal settlements in flood plains. • The vulnerability of people, ecosystems, and places when they are exposed to a particular hazard. Vulnerability considers the sensitivity of different subpopulations to risks, such as increased mortality among older adults to heat waves, as well as the capacity of individuals, public health departments, and health-care facilities to cope with a particular hazard now or in the future. Further, these factors need to be considered from a systems perspective. The factors determining hazard, exposure, and vulnerability interact differently across spatial and temporal scales to create risk. Populations living in certain regions may experience increased risks for specific health outcomes due to the baseline climate, natural resources such as freshwater supplies, vulnerability to storm surges, quality of the public health infrastructure, and access to health care (Balbus and Malina 2009). Socioeconomic factors interact with the physical threats; they may increase the likelihood of exposure, leading to differences in the ability to respond appropriately to a hazard, etc. Monitoring and surveillance therefore should include the relevant social, environmental, behavioral, and health factors that determine population health.

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Monitoring and Surveillance Data Needs Monitoring and surveillance should collect data to support analyses that: • Document past and current health burdens associated with the processes and consequences of global change, including estimating the extent to which trends could be attributed to global change. • Quantify relationships between global change and health outcomes. • Provide ongoing information on health burdens as well as trends in factors that affect health risks, including environmental, socioeconomic, and other variables. • Estimate possible future health burdens under different scenarios of environmental and socioeconomic change. • Identify adaptation and mitigation strategies, policies, and measures to manage current and future risks, including their costs, benefits, and co-benefits, and the likely residual risk. • Monitor the effectiveness of implemented options, including identifying opportunities to modify policies and measures within and outside the health sector to take into account changing conditions. National meteorological and hydrological services are the main sources for data on the hazards associated with global change, while data on who is exposed and their associated vulnerability are generally collected by health and other sectors. A variety of organizations and institutions collect data of relevance for monitoring global change. National meteorological and hydrological services collect data on temperature, precipitation, and other factors. Internationally, the Global Climate Observing System (GCOS), sponsored by the World Meteorological Organization; United Nations Educational, Scientific and Cultural Organization; the United Nations Environmental Program; and the International Council for Science, is charged with advising on global climate observations and overseeing implementation based on the United Nations Framework Convention on Climate Change (UNFCCC) standards for systematic climate observations and a sustained observing system (GCOS 2010). Among the requirements are supporting the attribution of the causes of climate change and supporting projections of global climate change, including characterizing extreme events, important to assessing possible impacts, adaptation options, risks, and vulnerability. The organization developed a list of 50 essential climate variables that were possible to implement globally, including variables such as temperature, precipitation, soil moisture, ground water, wind speed/direction, pressure, cloud properties, sea ice, sea level, and carbon dioxide. There are increasing numbers of integrated indices based on these variables, such as the US Climate Extremes Index that was developed to help identify possible trends or long-term variations in weather and climate extremes (Gleason et al. 2008). National and international health organizations and institutions monitor a range of climate-sensitive diseases because there is a long history of such diseases causing high morbidity and/or mortality, including the US Centers for Disease Control and Prevention, the European Centre for Disease Control, the WHO Global Alert and Response (GAR; including the Global Outbreak Alert and Response

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Network or GOARN), and the PROMED reporting network at the International Society for Infectious Diseases. Monitoring these networks can provide insights into changing infectious disease patterns, whether those changes are due to global change or other factors. Further understanding of the possible impacts of global change and disease transmission dynamics and better long-term data sets can suggest other opportunities for identifying regions at risk of emerging diseases (NRC 2001). When considering what to monitor, it is important to bear in mind that there does not need to be a large number of cases to cause significant societal impacts. For example, a weighted risk analysis of climate change-related impacts on emerging infectious diseases of possible concern for Europe assessed the strength of association between the infectious disease and climate change and the potential severity of the consequences of an outbreak to society (Lindgren et al. 2012). The analysis suggested that changes in current surveillance programs are needed for Lyme borreliosis, TBE, and dengue fever. The authors highlight that even the welldeveloped public health infrastructure in Europe needs modification to protect its populations from a changing climate. The needs are much greater in low- and middle-income countries.

Networks for Linking Health, Meteorological, and Other Data Highly industrialized countries are developing networks for linking health, meteorological, and other data related to the health risks of global change. In Europe, the European Centre for Disease Prevention and Control is creating a European Environmental and Epidemiology Network (E3) by linking existing datasets and resources to analyze, predict, and respond to changing communicable disease patterns due to global change (http://www.ecdc.europa.eu/en/healthtopics/ climate_change/Pages/index.aspx). In the USA, the National Environmental Public Health Tracking Program collects, analyzes, interprets, and disseminates data on hazards, exposures, and health from national and local sources (http://www.cdc. gov/nceh/tracking/). Current indicators focus on how climate change is altering heat-related risks, with more indicators planned for other risks.

Indicators of the Health Risks of Global Change An active area of research is developing a small number of indicators to monitor from the wide range of variables that influence the health risks of global change. Of the frameworks used for developing environmental health indicators, Hambling et al. (2011) identified the DPSEEA (Driving force–Pressure–State–Exposure– Effect–Action) framework as the most suitable approach to assess, quantify, and monitor human health vulnerability; design and target interventions; and measure the effectiveness of climate change adaptation and mitigation activities

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(see Figure 1). For climate change, driving forces include population growth, energy production and use, agriculture, transport policies, land use change, and urbanization. Pressures include greenhouse gas emissions and aerosols. The state of concern is long-term climate change. Exposures include extreme weather and climate events (heat waves, floods, drought), air pollutants, changing water quality, food availability and quality, and changes in the geographic range of vectors. The effect is the potential for a wide range of climate-sensitive health outcomes to increase in incidence, seasonality, and/or change their geographic range. The DPSEEA framework was designed to support decision making on options to reduce the burden of disease by describing environmental health problems from their root causes (e.g., driving forces and resulting pressure on the environment) through to exposures and their health effects and identifying different intervention points along the environmental health causal chain. It is a hierarchical approach that links measurable indicators to environmentally caused diseases and displays the various levels of action that can be undertaken to reduce environmental health impacts. The framework can be utilized to design and target interventions, as well as to monitor their performance. English et al. (2009) identified climate change and health indicators for the USA that were chosen to describe elements of environmental sources, hazards, exposures, health effects, and intervention and prevention activities. Some indicators are measures of environmental variables that can directly or indirectly affect human health, such as maximum and minimum temperature extremes, while others can be used to project future health impacts based on changes in exposure, assuming exposure–response relationships remain constant. Indicators were categorized into four areas: environmental, morbidity and mortality, vulnerability, and policy responses related to adaptation and greenhouse gas mitigation. These indicators cover measures that, if monitored, would track the magnitude and extent of health impacts.

Iterative Management Because the health risks of global change will continue to change with changes in environmental factors and socioeconomic development, it is important that monitoring and surveillance programs incorporate elements of iterative management (Ebi 2011). Iterative management can be designed to take into consideration the complexities of disease transmission systems and the inherent uncertainties with projections of future health impacts under different scenarios by formally managing programs using a “learning by doing” approach to build capacity for further adaptation as global change continues. This approach increases emphasis on monitoring and evaluation to provide early information on changes that could increase program efficiency and effectiveness under different environmental conditions (Fig. 74.1).

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Driving forces Population growth, energy, agriculture, transport policies, land-use change, urbanisation

Pressures GHG, aerosols, CFCs Action State Long-term climate change

Exposure Heatwaves, cold waves, flooding, drought, high wind, gradual temperature increase, air pollution Changes in environmental conditions, water scarcity, changes in vector ranges, food availability and quality

International and national policies Hazard management Global & national monitoring Mitigation & adaptation strategies Treatment

Health outcome Cardiovascular, acute & chronic respiratory diseases, acute diarrhoeal diseases, injuries, VBD, allergic diseases, others

Fig. 74.1 Driving force - pressure - state - exposure - effect - action (DPSEEA) framework applied to climate change (Hambling et al. 2011)

Cross-References ▶ Climate Change, Extreme Weather and Climate Events, and Health Impacts ▶ Emerging Infectious Diseases, Vector-Borne Diseases, and Climate Change ▶ Food and Water and Climate Change ▶ Global Change and Human Health, Introduction ▶ Health in the ‘Low-Carbon’ Economy ▶ Heat Waves, Human Health, and Climate Change ▶ Managing Risk and Responding to the Unknown

References Balbus JM, Malina C (2009) Identifying vulnerable subpopulations for climate change health effects in the United States. J Occup Environ Med 51:33–37 Ebi K (2011) Climate change and health risks: assessing and responding to them through adaptive management. Health Aff (Millwood) 30:924–930

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English PB, Sinclair AH, Ross Z, Anderson H, Boothe V, Davis C, Ebi K, Kagey B, Malecki K, Shultz R, Simms E (2009) Environmental health indicators of climate change for the United States: findings from the state environmental health indicator collaborative. Environ Health Perspect 117:1673–1681. doi:10.1289/ehp.0900708, http://dx.doi.org/ GCOS (2010) Implementation plan for the global observing system for climate in support of the UNFCC (2010 Update). GOOS-184, GTOS-76, WMO-TD/No. 1523, Geneva, 180 pp Gleason KL, Lawrimore JH, Levison DH, Karl TR, Karoly DJ (2008) A revised U.S. climate extremes index. J Clim 21:2124–2137. doi:10.1175/2007JCLI1883.1 Hambling T, Weinstein P, Slaney D (2011) A review of frameworks for developing environmental health indicators for climate change and health. Int J Environ Res Public Health 8, 1-x manuscripts. doi:10.3390/ijerph80x000x IPCC (2012) Managing the risks of extreme events and disasters to advance climate change adaptation. In: Field CB, Barros V, Stocker TF, Qin D, Dokken DJ, Ebi KL, Mastrandrea MD, Mach KJ, Plattner G-K, Allen SK, Tignor M, Midgley PM (eds) A special report of working groups I and II of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK/New York, 582 pp Last JM (2001) A dictionary of epidemiology, 4th edn. Oxford University Press, New York Lindgren E, Andersson Y, Suk JE, Sudre B, Semenza JC (2012) Monitoring EU emerging infectious disease risk due to climate change. Science 336:418–419 National Research Council (NRC) Committee on Climate Ecosystems Infectious Disease and Human Health, Board on Atmospheric Sciences and Climate (2001) Under the weather: climate, ecosystems, and infectious disease. National Academics Press, Washington, DC

Additional Recommended Reading Ebi KL (2009) Public health responses to the risks of climate variability and change in the United States. J Occup Environ Med 51:4–12 Frumkin H, Hess J, Luber G, Malilay J, McGeehin M (2008) Climate change: the public health response. Am J Public Health 98(3):435–445 Hess JJ, McDowell JZ, Luber G (2012) Integrating climate change adaptation into public health practice: using adaptive management to increase adaptive capacity and build resilience. Environ Health Perspect 120:171–179, http://dx.doi.org/10.1289/ehp.1103515 McMichael AJ, Lindgren E (2011) Climate change: present and future risks to health, and necessary responses. J Intern Med 270:401–413. doi:10.1111/j.1365-2796.2011.02415.x Wilson M, Anker M (2005) Disease surveillance in the context of climate stressors: needs and opportunities. In: Ebi KL, Smith J, Burton I (eds) Integration of public health with adaptation to climate change: new directions. Taylor & Francis, London, pp 191–214

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Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Co-Benefits of ‘Low-Carbon’ Development Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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There is growing evidence that activities to mitigate climate change by reducing emissions of greenhouse gases and other climate active pollutants, can have beneficial impacts on public health not only as a consequence of helping to limit the magnitude and speed of climate change but also, in the nearer term, as a result of changes in exposure to environmental pollution and health-related behaviors. Dietary changes, for example reductions in dietary saturated fat intake and replacement with unsaturates of plant origin, may help prevent cardiovascular and other disease risks in high-consuming populations. Transport interventions, especially those that promote active travel (increased walking and cycling), can help increase physical activity, although potentially at some additional risk of road injury, while fuel switching or more efficient vehicles could help reduce air pollution, especially in urban settings. Energy efficiency improvements to housing have the potential for positive and negative effects on indoor air quality and may help protect against the adverse health effects of low and high temperatures. Switching to low-carbon forms of electricity generation has the potential to reduce the health burdens of outdoor air pollution.

A. Haines (*) • P. Wilkinson London School of Hygiene and Tropical Medicine, London, UK e-mail: [email protected]; [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_106, # Springer Science+Business Media Dordrecht 2014

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Such “health co-benefits” of climate change mitigation policies provide an important additional rationale for accelerating the transition to ‘low-carbon’ economies and could help to counterbalance the inertia and vested interests that support unsustainable patterns of development. Keywords

Climate change mitigation • Health co-benefits • Air pollution • Noncommunicable diseases

Definition This paper describes the potential health co-benefits that can result from the implementation of policies to reduce greenhouse gas emissions.

Background Meeting the world’s growing energy demands will be one of the critical challenges for the twenty-first century. The efficient exploitation of energy resources has been crucial to the development of modern industrial societies. Yet while the science and technologies that underpin, and flow from, industrial development have been transforming for health (as for societies in general), dependence on fossil fuel energy coupled with extensive land-use changes (notably deforestation) has also brought substantial penalties. The scientific evidence for anthropogenic global warming is now strong. The changes to the climate over this century, though still uncertain in magnitude, are likely to be rapid and unprecedented in scale since the dawn of recorded history. They are predicted to have multiple adverse effects on the environment (disruption of ecosystems and ecosystem services, species loss), social integrity (population displacements, effects on livelihoods), the economy (reduced growth, altered agricultural viability, regional/local economic dislocations), as well as population health. At the same time, the most accessible fossil fuel resources are growing increasingly scarce, so that extraction of oil and other fuels can be achieved only at increasingly high financial and environmental costs, as shown by the 2010 Deepwater Horizon oil spill in the Gulf of Mexico, and from a diminishing number of sources of production (Wilkinson 2008). There is also growing recognition of the damage that overdependence on fossil fuels has on population health because of the associated emissions of toxic air pollutants, and because of its role in declining levels of physical activity (e.g., through increased private car use and labor-saving devices), increasing levels of overnutrition (arising from the production and supply of processed energy-dense foods) and increasing demand for animal products in emerging economies at the same time as food insecurity is increasing for many poor people, along with transport-related injury and mortality, and adverse effects on the quality of life within congested urban environments (Haines et al. 2009).

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With a world population rapidly growing in size and energy demands, concerns about the potential consequences of global environmental change, volatile food and energy prices, and both food and energy insecurity have become of primary importance. These concerns are motivating the search for newer, reliable, and less environmentally damaging sources of energy, particularly ones with lower greenhouse gas (GHG) emissions (some particles such black carbon can also contribute to climate change but for simplicity we use the term GHG emissions). The need for collective action to tackle the anthropogenic climate change has been comprehensively articulated in the assessment reports of the UN Intergovernmental Panel on Climate Change. However, policy makers in many countries are still showing reluctance to make the policy changes needed to move decisively towards a much lower level of GHG emissions. Concern that negative economic and social consequences may arise from policies to reduce greenhouse gas emissions is one factor holding back the necessary policies changes. In part this is due to perceived higher costs of low GHG technologies and reluctance to embrace major changes in lifestyle which might result in lower consumption patterns. Yet, relatively little attention has been given to the health and social impacts (many of them beneficial) that may follow the transition to ‘low-carbon’ economies in a range of different geographic and socioeconomic settings. (The term low carbon is used for simplicity to imply low emissions of GHGs, although they do not all contain carbon.)

Co-Benefits of ‘Low-Carbon’ Development Pathways There is a range of potential ancillary (or co-) benefits of ‘low-carbon’ development pathways which could prove attractive to policymakers in their own right and help to offset, to a greater or lesser extent, the costs of implementing low-carbon policies (Fig. 75.1). Many current estimates do not allow for the wider externalities impacts (from an economic perspective) that arise from these positive health of impacts (Haines and Dora 2012). The evidence to date is that many actions aimed at reducing greenhouse gas emissions have the potential for near-term, direct, and positive impacts on health. As Haines et al. (2009) note, these positive health effects “are important not only because they can provide an additional rationale to pursue mitigation strategies, but also because progress has been slow to address international health priorities such as the UN Millennium Development Goals (MDGs) and reductions in health inequities. Mitigation measures offer an opportunity not only to reduce the risks of climate change but also, if well-chosen and implemented, to deliver [substantial] improvements in health almost immediately.” These health co-benefits are additional to the benefits that are also expected to occur from reducing the magnitude of climate change. Quantitative estimates of these impacts are also subject to fewer uncertainties than those arising from reductions in future climate change. There are multiple pathways by which policies to reduce GHG emissions can also benefit health. Electricity generation based on the combustion of carbonaceous fuels gives rise to air pollution with quantifiably large adverse impacts on

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Diet and nutrion Physical acvity

Transport: low C fuels, acve travel

Traffic injury and mortality

Social cohesion Noise Chronic disease

Housing: energy efficiency

Indoor temperature Indoor air quality Mental well-being

Low C power generaon

Outdoor air polluon

*Assumes replacement of animal source saturated fats with unsaturated fats of plant origin to achieve reducons in cardiovascular disease. Increased fruit and vegetable consumpon would achieve addional health benefits.

Fig. 75.1 Key pathways to health from a low-carbon economy

population health. The fuels that are most damaging in terms of carbon dioxide emissions are also those with the most seriously adverse health effects mediated through fine particulate (PM2.5) air pollution, with coal and especially lignite being particularly damaging. Road transport also contributes to fine particulate air pollution as well as tropospheric ozone and other pollutants. Globally, ambient fine particulate air pollution has been estimated to be responsible for around 3.2 million deaths annually, with some contribution from household sources’ (Lim et al 2012). The mortality in cities with high levels of pollution exceeds that observed in relatively cleaner cities by 15–20 %. Even in the EU, average life expectancy is reduced by an estimated 8 months or so due to exposure to PM2.5 produced by human activities. A number of studies have estimated the health benefits from low-carbon electricity generation. In the case of India, for example, it has been estimated that around 90,000 premature deaths annually could be averted by such policies as a result of reduced atmospheric concentrations of fine particles (Markandya et al. 2009). In high-income nations the benefits would be less because of existing more stringent air pollution legislation and controls, but the gains are still substantial. Very high levels of particulate air pollution are experienced in indoor environments where solid fuels are used for cooking and heating. Recent estimates suggest around 3.5 million deaths per annum worldwide due to household air pollution

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(Lim et al 2012), particularly from acute lower respiratory infections in children and chronic obstructive pulmonary disease in women. Even when solid fuels are from potentially renewable sources such as wood, they may contribute to climate change though products of incomplete combustion such as black carbon which acts as a greenhouse pollutant and accelerates the melting of glaciers when it is deposited on them. A hypothetical program to install 150 million improved cooking stoves over a decade in India was estimated to avert around two million premature deaths, largely in children and in women, as well as yielding useful reductions in greenhouse pollutants (Wilkinson et al. 2009). In high-income countries there is also the potential for policies that improve health while reducing greenhouse gas emissions through improved energy efficiency (insulation, ventilation control) of homes and by switching to cleaner fuels. Improved energy efficiency may help reduce cold- and, often, heat-related exposures in the home, and tighter air control can protect against the ingress of pollution from the outdoor air, especially in urban settings. However, reduced air exchange can exacerbate levels of indoor pollutants derived from indoor sources (combustion products, radon, second-hand tobacco smoke, volatile organic compounds from furnishings and other materials) and mold growth. In dwellings that are very airtight, this can be offset by the use of mechanical ventilation with heat recovery (MVHR) systems if the incoming air is filtered. But MVHR systems and their filters need to be well installed and properly operated and maintained. Additional, but as yet uncertain, benefits to health could accrue as a result of increased indoor winter temperatures in temperate climates and their impact on fuel poverty. One study identified 14 measures targeting methane and black carbon emissions that reduce projected global mean warming by 0.5  C by 2050. These yield a reduction of 0.7–4.7 million annual premature deaths from outdoor air pollution and increase annual crop due to ozone reductions in 2030 and beyond. The value of the benefits is substantially greater than the marginal costs of mitigation (Shindell et al. 2012). The urban transport sector offers major potential for improved health and reduced GHG emissions particularly because of the effect of sedentary lifestyle on increasing the risk of a number of conditions including ischemic heart disease, stroke, dementia, diabetes, and cancer of the breast and large bowel. Increased injuries are likely from greater exposure of walkers and cyclists to road danger, but these are greatly outweighed by the health benefits of increasing physical activity and can be reduced further by policies, e.g., to separate cyclists and motorized traffic. Increased efficiency of engines or electric vehicles can result in reduced air pollution but does not lead to increased physical activity. Historically increasing efficiency of fuel use has often led to increased consumption which more than offsets any reductions in GHG emissions. Thus, policies to enhance efficiency of fuel use need to be accompanied by GHG abatement policies in order to reduce overall emissions. Greater reliance on rapid transit systems and walking and cycling lead to lower air pollution and noise levels and fewer traffic injuries and promote physical activity. Transport interventions and urban planning are among the most effective interventions to promote physical activity and to reduce socially disruptive influences of busy congested roads.

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The potential health benefits of policies to promote increase active travel (walking and cycling) could result in substantial savings to national health systems. One example of the impact of such policies in urban England and Wales suggested that the cost averted could amount to around £17 billion over 20 years and increase over that time because of the lag period between any increases in physical activity and the consequent health-care costs averted (Jarrett et al. 2012). The lag period is likely to vary according to the health outcome, being much longer for dementia or cancer of the large bowel or breast than, say, diabetes or ischemic heart disease. In the USA a study which included both air pollution benefits and physical activity benefits by curtailing short car journeys and replacing them with walking and/or cycling found that the resulting net health benefits were $7 billion (£4.6 billion) per annum in a US midwest population of around 30 million (Grabow et al. 2012). These are considerably greater per capita benefits than in the previous example. However, this discrepancy may be because of the different methods used to estimate the health and economic effects as well as potential differences between the populations in terms of baseline physical activity. In the food and agriculture sector, 80 % of GHG emissions are related to animal products in part because of methane (a powerful GHG) emissions from ruminants. Agriculture is estimated to be responsible for around 10–12 % of global GHG emissions and much more if land-use change, such as deforestation, is taken into account. Dietary change, including reducing animal product saturated fat consumption with replacement with unsaturated fatty acids from plant sources (Friel et al. 2009). However, it would not be appropriate to reduce production and consumption in low-consumption societies or in pastoralist communities which depend on livestock for their livelihoods. Poorly designed mitigation policies could however have adverse impacts on health. Examples include the potential to increase road injuries and deaths in transport policies that promote active transport (walking and cycling) without segregation or adequate additional protection of cyclists and pedestrians; the worsening of indoor air pollution quality when household energy efficiency is in part achieved through reduction of ventilation/air exchange; and the possible adverse effects on low-income families of energy policies that contribute to increases in fuel prices. The last of these may be particularly relevant in international terms, where rises in fuel cost can lead to lower-income households falling down the “energy ladder resulting in the use of more polluting but cheaper fuels.” There are also important differences in the magnitude and even direction of health co-benefits, depending on the context in which they are implemented: so, for example, in the case of a scenario to substantially increase active travel in London and Delhi, there are likely to be increases in road injuries in London but decreases in Delhi because of different projections of the business as usual counterfactual scenarios (Woodcock et al. 2009). In the case of Delhi, major increases in motor vehicle use are projected under the BAU scenario but much less so under a “sustainable transport” scenario; in London under the BAU scenario, little change in traffic density is projected. Likewise, biofuel policies may have a negative

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impact on health by raising food prices if the crops grown to provide feed stocks compete with food crops but not if they are from crops that do not compete for agricultural land. The detail of interventions and the mechanisms by which they are achieved matter therefore. Most of the research to date on health impacts has focused on the selected exposures that are easiest to quantify (rather than necessarily being the most important for health) and generally have assumed achievement of necessary policy changes rather than considering the processes by which such change can be attained. There has also been insufficient integration of the impacts in different policy areas and there needs to be better assessment of practicality, acceptability, and cost-effectiveness/cost-benefit in different settings. Nevertheless, it is clear that many drivers of common diseases are closely related to the profligate use of energy and resources in industrialised societies, and the factors which undermine environmental sustainability are in many cases those which also cause a heavy burden of disease. There are still questions however about how best to change policies to both reduce GHG emissions and improve health. It seems likely that a range of policy changes will be necessary including removal of harmful fossil fuel and agricultural subsidies and shifting the tax burden to address harmful externalities such as through carbon (and perhaps saturated fat) taxes. However, poorly designed taxes can be regressive, resulting in the poor-bearing disproportionate share of the tax burden. Thus, policies need to integrate social (including health), economic, and environmental goals in order to improve health, reduce inequities, and promote environmental sustainability.

Conclusions The health co-benefits of climate change mitigation policies should have a higher profile in national policies and international negotiations to reduce GHG emissions. They hold promise for addressing multiple policy objectives simultaneously and counterbalancing the vested interests that are supporting current unsustainable patterns of development.

References Friel S et al (2009) Public health benefits of strategies to reduce greenhouse-gas emissions: food and agriculture. Lancet 374(9706):2016–2025 Grabow ML et al (2012) Air quality and exercise-related health benefits from reduced car travel in the midwestern United States. Environ Health Perspect 120(1):68–76 Haines A, Dora C (2012) How the low carbon economy can improve health. BMJ 344:e1018 Haines A et al (2009) Public health benefits of strategies to reduce greenhouse-gas emissions: overview and implications for policy makers. Lancet 374(9707):2104–2114 Jarrett J et al (2012) Effect of increasing active travel in urban England and Wales on costs to the National Health Service. Lancet 379(9832):2198–2205

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Lim S S et al (2012) A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010 Lancet 380(9859):2224–2260 Markandya A et al (2009) Public health benefits of strategies to reduce greenhouse-gas emissions: low-carbon electricity generation. Lancet 374(9706):2006–2015 Shindell D et al (2012) Simultaneously mitigating near-term climate change and improving human health and food security. Science 335(6065):183–189 Wilkinson P (2008) Peak oil: threat, opportunity or phantom? Public Health 122(7):664–666, discussion 669–670 Wilkinson P et al (2009) Public health benefits of strategies to reduce greenhouse-gas emissions: household energy. Lancet 374(9705):1917–1929 Woodcock J et al (2009) Public health benefits of strategies to reduce greenhouse-gas emissions: urban land transport. Lancet 374(9705):1930–1943

Additional Recommended Reading Haines A et al (2012) From the Earth summit to Rio+20: integration of health and sustainable development. Lancet 379(9832):2189–2197 Health in the green economy. http://www.who.int/hia/green_economy/en/ UN Intergovernmental Panel on Climate Change. http://www.ipcc.ch/publications_and_data/ publications_and_data_reports.shtml#.UHmlnlEtl8E

Part VIII Global Change and Food Security Marta G. Rivera Ferre

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Geoffrey Lawrence and Philip McMichael

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Globalization of Markets and Finance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Environmental Impacts of Population Increases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Resource Depletion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Readings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

Food security is compromised when people, for any number of reasons, are deprived of the ability to access safe and nutritious foods on a regular basis. Currently, about one in 8 of the world’s human population is food insecure and suffers from malnutrition. The causes of malnutrition are many and include the failure of markets and distribution channels, financial speculation, the depletion of resources under population pressures, the continuation of inappropriate farming methods, and climate change. This chapter explores these, and other, factors impinging upon food security. It raises the important question of how the world’s growing population can receive adequate, nutritious, food when the current trajectory for farming is unsustainable and there are emerging, widespread, resource limitations.

G. Lawrence (*) The University of Queensland, Brisbane, Australia e-mail: [email protected] P. McMichael Cornell University, Ithaca, NY, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_114, # Springer Science+Business Media Dordrecht 2014

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Keywords

Globalization • Food security • Neoliberalism • Population growth • Resource depletion • Climate change

Definition “Food security exists when all people at all times have physical, social and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life” (FAO 2012, p. 4). Food security is often understood as comprising four pillars: availability (supply), access (entitlements), utilization (the body’s ability to metabolize food nutrients, which might be impaired by illness), and stability (without periodic or seasonal shortfalls in the provision of food). Currently there are some 868 million people – or more than 12 % of the world’s population – who are malnourished, the vast majority in developing countries (FAO 2012). There are many factors that will impact upon future food security for the human population, including the ways in which the market and finance systems operate, environmental impacts of population increases, resource depletion, and climate change. It is predicted that, in combination, these factors will result in growing food insecurity for people in the world’s poorest nations, unless some substantial adjustments are made toward lower input, sustainable, farming.

The Globalization of Markets and Finance Neoliberal policies, largely adopted by key international institutions and their member states, assume that global free trade and market mechanisms will provide the greatest possible economic benefits to the greatest number of people. Neoliberal policies encourage smaller government to expand the business environment. National and global economic growth, therefore, depend on removing tariffs and other barriers to trade, extending private property rights and worker contracts, privatizing public sector activities in the economy, restructuring state regulation to increase opportunities for corporate activity, lowering taxes on corporate profits and capital gain, and relying upon market mechanisms to solve problems relating to resource distribution (Heynen et al. 2007). The global implementation of these policies has stimulated the creation of the “world factory” manufacturing goods utilizing components from various sites – with labor-intensive work usually located in the global South in sprawling urban cities and in export processing zones. The increasingly urbanized populations of these nations are fed by the industrialized “world farm” (McMichael 2012). This global integration of industrial agriculture with export manufacturing stems from the WTO’s Agreement on Agriculture (1995) which removed food trade barriers, thereby compromising policies of food self-sufficiency in many countries (Fairbairn 2010). In accordance with neoliberal policy, if developing nations can

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import cheaper foods, they benefit from the principle of comparative advantage (each nation should specialize in the production of goods and services that, in comparative terms, it can produce more efficiently than competing nations). However, cheaper foods imported from the USA and EU are derived from a subsidized and distorted system which artificially lowers the costs of production and gives farmers in the North an unfair advantage (Rosset 2006). When global prices are low, this can provide “cheap food” (Carolan 2011), but when food prices rise, consumers in these importing nations are vulnerable. They have changed their diets to match the imported products (such as soy, white rice, corn, and processed foods). Meanwhile, their own agricultural lands have been turned over to plantations and large-scale farming enterprises growing export commodities such as rubber, coffee, palm oil, and out-of-season vegetables destined for consumers in the North (McMichael 2012). According to the peasant-based organization La Vı´a Campesina, smallholders across the world are marginalized by the policies that favor global trade: they simply cannot compete with large-scale, subsidized, agro-industrial farms (see Rosset 2006). Food dependency is a structural outcome in much of the developing world. Alternatively, La Vı´a Campesina promotes food sovereignty (the right of people to healthy and culturally appropriate foods that are produced in sustainable ways and the right of countries to consume, rather than trade, the food they produce) as the best means of addressing problems of food insecurity (Forum for Food Sovereignty 2007). This stands in marked contrast to the “free trade” regime that supplies food only to those consumers with purchasing power. Food security occurs when there is sufficient, safe, and nutritious food available to all (McDonald 2010). For this to occur, food must be both available and accessible, and it is the latter where most of the problems arise. The world produces enough food (in terms of calories) to feed humans, but there are circumstances where food cannot be accessed (Burke and Lobell 2010). That is, it is the vastly uneven distribution of food that is a major concern today and is likely to be in the future (FAO 2013). If people are landless, they cannot produce food for themselves and their neighbors (and world hunger is concentrated in rural areas); if they lack income, they cannot purchase food; if cropland is diverted to biofuel production or animal feed, there is likely to be less available for human consumption. Here, markets have privileged other uses of land over that of producing staple foods, at the expense of food security. Markets are also giving signals to financiers to target food and land for new forms of profit making. Under neoliberalism, a more deregulated system of global finance is playing an increasingly important role in generating food insecurity. For some 75 years in the USA, “futures” trading in farm products was regulated to prevent widespread speculation. When limits on speculative trading were lifted by the US Commodity Futures Trading Commission in 2000, commodity index funds became a mechanism for quite heavy speculation (ITUC 2009; Clapp 2012), with global food prices rising by some 83 % between 2007 and 2008 (Tenenbaum 2008). The market volatility that led to the sharp increases in food prices in 2008 is likely to continue – given that the causes have yet to be addressed (de Janvry and Sadoulet 2012). Financial entities are also purchasing land for capital growth, speculation, and

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biofuel production and, in the case of sovereign wealth funds, for the repatriation of food to oil-rich but soil- and water-poor nations. Subsistence farmers are often removed from the land, increasing local food insecurity (McMichael 2010a, b). Such “land grabbing” is coming to be viewed as a “twofold transnational contest for control over resources and authority over institutions” (Margulis et al. 2013, p. 11).

Environmental Impacts of Population Increases On present trends, the human population is expected to reach 9.3 billion by 2050, an increase of some 2.3 billion from 2012 (UN 2011). In graphic terms this is equivalent to creating, and feeding, a new city of one million people every 5 days from now until 2050. This presents the world with a choice – to shift priorities for land use from fuel and feed crops to food crops and stabilize smallholding or to intensify production. Food production would have to increase by 70 % from present-day levels to feed the expanded population in a business as usual scenario. It was Thomas Malthus in 1798 who first proposed that the human population would grow faster than food could be produced to feed them – leading to misery, famine, and death. However, technological developments (particularly industrial farming methods) have boosted crop yields and encouraged the factory farming of animals which – while largely unsustainable – have produced food in abundance (Carolan 2011) but only for those with purchasing power. Given this scenario, neo-Malthusians argue that further population growth will only exacerbate poverty and global inequality. Research in Africa has cautioned against viewing population growth as “inevitably” intensifying food insecurity. In some regions (northern Nigeria, southern Kenya, and southwestern Uganda) population increases have accompanied transformations in farming systems which now utilize sustainable options such as intercropping, legumes, animal manure, and terracing. Quite substantial increases in food production have resulted, challenging the “pessimistic neo-Malthusian narratives about agriculture in Africa” (Adams 2010, p. 354). This has occurred not with the input of overseas experts and “miracle” biotechnologies (Adams 2010, p. 359) but with local-level, community-based, agroecological approaches that result in forms of agricultural intensification that are both sustainable and supportive of small-scale farming. A growing body of scientific research confirms that lower-input diversified farming (organic or agroecological) matches and can exceed productivity levels of large-scale industrial agriculture, with considerably less stress on ecosystems and with less emissions (Pretty et al. 2006; Badgley and Perfecto 2007; McIntyre et al. 2009). Accordingly, it is not population growth that is the problem so much as how populations will be provisioned. Can the world’s population grow to 9.3 billion without compromising environmental integrity? Each individual on the planet utilizes natural resources for food, shelter, heating, cooking, washing, and so forth – but this varies considerably from country to country, based upon different levels of consumption. The Global Footprint Network (2013a) has developed an

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index of a nation’s “Ecological Footprint” – defined as the area of biologically productive land and seawater that is required to produce the resources a nation consumes and to absorb the wastes it generates, under prevailing technologies and resource management practices. The Global Footprint Network has estimated that the USA requires 7.2 global hectares (gha) of land and seawater per person to provide those in the USA with their current standard of living. The figure is 6.7 for Australia, 0.7 for Bangladesh, 1.2 for Cambodia, 4.9 for France, 0.6 for Haiti, 4.3 for New Zealand, 11.7 for Qatar, 2.55 for Turkey, and 4.7 for the UK. What is of concern is that the earth’s ecological limits have already been exceeded. The earth’s biocapacity is estimated to be 12 billion gha – or some 1.8gha per person. However, humanity’s Ecological Footprint has been calculated as 18.2 billion gha – or some 2.7gha per person (Global Footprint Network 2012, p. 5). That is, feeding people at present rates of consumption is currently taking the equivalent of 1.5 planets. This is unsustainable. Yet, as populations grow and as consumers in developing countries adopt Western habits, humanity is likely to have an even greater Ecological Footprint. It is sobering to learn that if everyone in the world lived at the same standard as those in the USA, the land and water resources of four planet earths would be required to satisfy that level of demand (Global Footprint Network 2013b).

Resource Depletion Many natural resources required for food, feed, and fuel production, distribution, and utilization are being depleted. Forests have been cut down to provide land for more cropping and grazing, but removal of trees compromises local ecosystems. Forests convert carbon dioxide into oxygen, reducing the greenhouse gasses that contribute to global warming. Tree removal can lead to soil erosion, the leaching of minerals, and, eventually, desertification. Desertification – literally the creation of deserts from once-productive soils – compromises the ability of the earth to produce more food. It is estimated that some 24 billion tons of the earth’s topsoil is washed or blown away annually which, in the last two decades, equates to an area the size of all the farmland of the USA (UNESCO 2013). Today, desertification affects some 25 % of the land surface of the earth and threatens the lives of over a billion people, many of them marginalized and resource-poor and unable to counteract the degradation that is occurring (IFAD 2013). Desertification is a process that will continue as lands are cleared for urban occupation and for agricultural activities and as severe weather events (floods and droughts) become more frequent as a consequence of climate change (UNESCO 2013). Intensive farming practices also affect soil degradation. Salinization occurs when salts in lower levels of the soil rise to the surface as a result of tree clearing and large-scale irrigation practices. Salts limit water uptake by plants and so reduce agricultural production (Goldie et al. 2005). Acidification occurs when excessive amounts of ammonium-based fertilizers leach into lower soil horizons. The effect is to reduce root growth of crops which, again, reduces farm output (Gazey 2009).

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Both salinization and acidification are symptoms of an unsustainable agricultural production system which harnesses farmers to the profit-making requirements of transnational agribusiness (Gray and Lawrence 2001; Carolan 2011). Soil degradation is expected to continue as farmers throughout the world intensify production (Oosterveer and Sonnenfeld 2012). According to Cribb (2010, p. 54): humanity is degrading about 1 percent of its productive land every year. This may not sound like much – but, left unaddressed, it will ruin two-thirds of the world’s productive land by 2050. This will obliterate gains made by expanding the area farmed and improving crop yields.

Water resources are also a concern for food security. Approximately one-fifth of the world’s population live in areas where freshwater is scarce and another quarter face “economic” water shortages, where governments do not possess the infrastructure necessary to procure available sources (UN Water 2007, p. 4). In most nations it is farming that consumes most water, so if water is limited, food production suffers. Meanwhile, urban water demands are growing and could ultimately use up to half of all the freshwater available, globally, by 2050, leaving farmers to attempt to grow more food with a decreasing supply of water (Cribb 2010). Greater efficiencies in irrigation will be one way of helping to better utilize water resources, or water conservation techniques, but other problems are emerging that also must be addressed: increasing level of contamination of streams and rivers, the draining of aquifers that provide essential drinking water, and the need to return water to the environment (Cribb 2010; Oosterveer and Sonnenfeld 2012). Finally, current resources employed to produce food will become progressively scarce and ultimately more expensive, leading to food price increases (Lawrence et al. 2010). Oil is essential to industrial agriculture and food supply, providing diesel for the operation of farm machinery, fertilizers for soil enhancement, and insecticides for pest control. Phosphorus is crucial to plant growth. Yet, “peak oil” is expected to occur between 2010 and 2020, and “peak phosphorus” will be close behind (Cribb 2010), and we can expect a steady decline in their availability. In the absence of replacement inputs and new farming technologies (including enhanced agroecology), the world will struggle to increase its food supply (Cribb 2010). In line with this scenario, any food price increases will ensure more of the world’s people will experience poverty and suffer malnutrition (ITUC 2009). The vast majority of these people will be in the global South (Patel 2007).

Climate Change Climate change will have quite significant impacts upon food security. Agriculture has always been vulnerable to weather fluctuations, but the predicted effects of future climate change are of a different magnitude. The main changes that are expected to occur if global temperatures increase by two degrees are:

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• A rise in sea levels – with many low-lying regions (particularly productive river deltas) being inundated with sea water, leading to reduced agricultural output and significant displacement of human populations • Altered patterns of rainfall, including more unreliable falls in the subtropics – resulting in further desertification in drier regions • Extreme weather events – droughts, floods, cyclones, and prolonged hot and cold snaps • Hotter average temperatures which will reduce moisture in soils and limit plant growth • Declining availability of freshwater for agricultural, and more direct human consumption, usage • Increased agricultural yields in some areas but a general reduction in agricultural yields in most other regions • The proliferation of pests and diseases – including their movement to new locations • A reduction in biodiversity (IPCC 2007; Solomon et al. 2007; Stern 2007). The fourth report of the Intergovernmental Panel on Climate Change (see IPCC 2007, p. 275) predicted negative consequences for food production as a result of increased temperatures, droughts, flooding, and pest and disease outbreaks, which would reduce crop yields and livestock productivity. An overall decline in the growth rate of world agricultural productivity was expected – over the last three decades growth has been at 2.2 % per year. But this is expected to decline to 1.6 % per year from 2000 to 2015 and 1.3 % per year from 2030 to 2050 (IPCC 2007, p. 280). Food production could improve marginally in the high-latitude countries (Canada, Europe, and Russia), but low-latitude regions (the subtropics, the Mediterranean, and Australia) are expected to experience production declines. The impact of climate change on developing countries is expected to be significant. Across much of Africa production from rain-fed agriculture could decline by up to 50 % by 2020 (AMCEN 2012). In particular, sub-Saharan and southern African countries which have been denuded of forest cover and already suffer water shortages are predicted to experience longer and more frequent droughts, while the highly productive delta farming regions in nations like Bangladesh are expected to be inundated as sea levels rise (Omenya et al. 2012; Oosterveer and Sonnenfeld 2012). Globally, agriculture is going to be the main sector of the economy most damaged by climate change. Consequently, those whose livelihoods are based upon farming and grazing are expected to be the most affected by the impacts of climate change (Burke and Lobell 2010). These are the rural peoples of developing nations who are already food insecure and whose levels of essential micronutrients will fall as yield losses are experienced: they will also become more susceptible to disease (Burke and Lobell 2010, pp. 27–28). According to Sir Nicholas Stern (2007), climate change represents the greatest market failure of our time: agriculture and manufacturing industry have been externalizing the costs of carbon pollution for which the planet – not the polluter – has paid and will continue to pay. And Stern confirms that while climate change will impact upon all nations, it will be the poorer countries – those which

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have contributed very little to climate change – which will experience the worst of climate change excesses (Stern 2007). Unfortunately, the two-degree tolerable limit increase listed by Stern is now considered a significant underestimation, with IPCC predictions that there could be a 6  C increase by the end of the century as carbon emissions continue, unabated. Even a three- to four-degree temperature increase will have devastating effects, resulting in flooding and displacement of up to 200 million people (Stern 2007). To reduce the effects and impacts of climate change, it will be essential to manage landscapes both for agricultural production and for the environment (the maintenance of the so-called ecosystem services), and it is considered that agroecological approaches which recycle nutrients, improve soils, carefully manage water and vegetation, and reduce pollution hold significant promise (Rosegrant and Cline 2003; Lawrence and McMichael 2012).

Conclusion Global food security will remain a matter of worldwide concern for the foreseeable future. The extent to which food (in)security will affect populations will be determined by the operation of market and finance systems, the environmental impacts of population and production ecologies, the level of resource depletion, and the magnitude of climate change. It would be remiss not to acknowledge the significant efforts being made on the part of global organizations such as the FAO and UN, national governments, activist groups, NGOs, farmer organizations, and community environmental groups which are seeking ways to make the world more food secure. At the individual level, many citizens are becoming “greener” by reducing their own Ecological Footprint. However, a bigger question remains: are current efforts enough to address global food insecurity now and into the future? The task will be to place agriculture and food systems on a sustainable trajectory while increasing food output and reducing greenhouse gas emissions – without compromising biodiversity and while, at the same time, lifting the world’s poorest people out of poverty. This will be a major challenge for humanity. Acknowledgments This chapter was part-funded by the Australian Research Council (Project Nos. DP0773092 and DP 110102299), by the National Research Foundation of Korea (NRF-2010330-00159) and the Norwegian Research Council.

References Adams W (2010) Society, environment and development in Africa. In: Redclift M, Woodgate G (eds) The international handbook of environmental sociology, 2nd edn. Edward Elgar, Cheltenham, pp 349–363

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AMCEN (2012) Fact sheet: climate change in Africa – what is at stake? Excerpts from IPCC reports, the Convention, and BAP. http://www.unep.org/roa/amcen/docs/AMCEN_Events/ climate-change/2ndExtra_15Dec/FACT_SHEET_CC_Africa.pdf. Accessed 14 July 2013 Badgley C, Perfecto I (2007) Can organic agriculture feed the world? Renew Agr Food Syst 22(2):80–85 Burke M, Lobell D (2010) Climate effects on food security: an overview. In: Lobell D, Burke M (eds) Climate change and food security: adapting agriculture to a warmer world. Springer, Dordrecht, pp 13–30 Carolan M (2011) The real cost of cheap food. Earthscan, London Clapp J (2012) Food. Polity, Cambridge Cribb J (2010) The coming famine: the global food crisis and what we can do to avoid it. University of California Press, Berkeley De Janvry A, Sadoulet E (2012) Subsistence farming as a safety net for food-price shocks. In: Cohen M, Smale M (eds) Global food-price shocks and poor people: themes and case studies. Routledge, London, pp 18–26 Fairbairn M (2010) Framing resistance: international food regimes and the roots of food sovereignty. In: Wittman H, Desmarais A, Wiebe N (eds) Food sovereignty: reconnecting food, nature and community. Fernwood, Nova Scotia, pp 15–32 FAO (2012) The state of food insecurity in the world, 2012. FAO, Rome FAO (2013) Food security. http://www.fao.org/docrep/006/Y5061E/y5061e08.htm. Accessed 24 Mar 2013 Forum for Food Sovereignty (2007) Declaration of Nyeleni. http://www.nyeleni.org/spip.php? article290. Accessed 26 Mar 2013 Gazey C (2009) Soil acidity needs your attention. http://biosecurity.wa.gov.au/objtwr/ imported_assets/content/fm/small/nw16_soil%20acidity_lr.pdf. Accessed 1 May 2010 Global Footprint Network (2013a) Glossary. http://www.footprintnetwork.org/en/index.php/GFN/ page/glossary/#Ecologicalfootprint. Accessed 27 Mar 2013 Global Footprint Network (2013b) Country trends. http://www.footprintnetwork.org/en/index. php/GFN/page/trends/unitedstates/. Accessed 27 Mar 2013 Global Footprint Network (2012) The national footprint accounts, 2011th edn. Global Footprint Network, Oakland Goldie J, Douglas B, Furnass B (eds) (2005) In search of sustainability. CSIRO Publishing, Victoria Gray I, Lawrence G (2001) A future for regional Australia: escaping global misfortune. Cambridge University Press, Cambridge Heynen N, McCarthy J, Prudham S, Robbins P (2007) Introduction: false promises. In: Heynen N, McCarthy J, Prudham S, Robbins P (eds) Neoliberal environments: false promises and unnatural consequences. Routledge, London, pp 1–21 IFAD (2013) Tackling land degradation and desertification. http://www.ifad.org/events/wssd/gef/ gef_ifad.htm. Accessed 10 Mar 2013 IPCC (2007) Climate change 2007: impacts, adaptation and vulnerability. Cambridge University Press, Cambridge ITUC (2009) A recipe for hunger: how the world is failing on food. International Trade Union Confederation, Brussels Lawrence G, McMichael P (2012) The question of food security. Int J Sociol Agr Food 19(2):135–142 Lawrence G, Lyons K, Wallington T (eds) (2010) Food security, nutrition and sustainability. Earthscan, London Margulis M, McKeon N, Borras S (2013) Land grabbing and global governance: critical perspectives. Globalizations 10(1):1–23 McDonald B (2010) Food security. Polity, Cambridge McIntyre B, Herren H, Wakhungu J, Watson RT (eds) (2009) Agriculture at the crossroads: international assessment of agricultural knowledge, science and technology for development. Island Press, Washington, DC

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McMichael P (ed) (2010a) Contesting development: critical struggles for social change. Routledge, New York McMichael P (2010b) Agrofuels in the food regime. J Peasant Stud 37(4):609–629 McMichael P (2012) Development and social change: a global perspective, 5th edn. Sage, Los Angeles Omenya A, Lubaale G, Miruka C (2012) Climate change and food insecurity in Mombasa: institutional and policy gaps. In: Fraybe B, Moser C, Ziervogel G (eds) Climate Change, Assets and food security in Southern African cities. Earthscan, London, pp 150–162 Oosterveer P, Sonnenfeld D (2012) Food, globalization and sustainability. Earthscan, London Patel R (2007) Stuffed and starved. Portobello Books, London Pretty J, Noble A, Bossio D, Dixon J, Hine R, Penning de Vries F, Morison J (2006) Resource conserving agriculture increases yields in developing countries. Environ Sci Technol 40(4):1114–1119 Rosegrant M, Cline S (2003) Global food security: challenges and policies. Science 302:1917–1919 Rosset P (2006) Food is different: why we must get the WTO out of agriculture. Fernwood, Nova Scotia Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt K, Tignor M, Miller H (eds) (2007) Contribution of Working Group 1 to the Fourth Assessment Report on the Intergovernmental Panel on Climate Change, 2007. Cambridge University Press, Cambridge Stern N (2007) The economics of climate change: the Stern review. Cambridge University Press, Cambridge Tenenbaum D (2008) Food vs. fuel: diversion of crops could cause more hunger. Environmental Health Perspectives 116(6):A254–A257 UN Water (2007) Coping with water scarcity: challenge of the twenty-first century. FAO, Rome UNESCO (2013) Definition of desertification. http://www.unesco.org/mab/doc/ekocd/chapter1. html. Accessed 27 Mar 2013 United Nations (UN) (2011) 2010 Revision of world population prospects population database. Department of Economic and Social Affairs, Population Division, http://esa.un.org/unpd/wpp/ unpp/panel_population.htm. Accessed 14 July 2013

Additional Recommended Readings Carolan M (2012) The sociology of food and agriculture. Earthscan, London Koc M, Sumner J, Winson A (2012) Critical perspectives in food studies. Oxford University Press, Canada Weis T (2007) The global food economy: the battle for the future of farming. Zed Books, London Young E (2012) Food and development. Routledge, Oxford

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Contents The Utility of a Food Systems Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vulnerability to Global Environmental Change and Food Security . . . . . . . . . . . . . . . . . . . . . . . . . . . Framing Adaptation in Food Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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The Utility of a Food Systems Approach Social science explanations of how and why people are vulnerable have stressed the importance of context (the social, economic, political, cultural, and other root causes or structural factors) in determining the nature of such vulnerability (O’Brien et al. 2007; Adger 2006; Bohle 2001). They have also argued that vulnerability must be understood as dynamic and interactive, not a static condition that can be assessed with linear causal models. These arguments make particular sense in the case of analyzing how food security will be affected by global environmental change. Food security is a multidimensional phenomenon (Ericksen 2008a), with four main components (availability, access, utilization, and stability). Each of these is in turn influenced by multiple factors (Ziervogel and Ericksen 2010). Thus food availability is in part determined by how much food is produced, but also by how well such food is distributed. Access to food is critically a function of income, along with functioning markets. Utilization of food depends upon social preferences as well as adequate human health, in addition

P. Ericksen CGiAR and International Livestock Research Institute, Nairobi, Kenya e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_121, # Springer Science+Business Media Dordrecht 2014

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to the availability of nutritious food. Food insecure households are often the poorest and marginalized groups, or those with poor health. Systems approaches are useful because of their attention to dynamic interactions among different components (Ison et al. 1997). Food systems include the set of activities beginning with producing food through to consuming food (Ericksen 2008), encompassing both ecological and social systems. Food security is the main outcome of food systems, with human welfare and environmental outcomes as secondary outcomes. Ericksen and others (2010) have argued that only by taking a systems approach can analysts fully understand how global environmental change may affect food security, through impacts not only on agricultural production but also via economic, cultural, and other factors. A systems approach also allows dynamic interactions to be evaluated over time and at multiple spatial levels (e.g., from households to communities).

Vulnerability to Global Environmental Change and Food Security Much has been written about the importance of framing vulnerability to global environmental change (O’Brien et al. 2007; Adger 2006; Ericksen 2008b), with authors arguing that the framing of an analysis determines the understanding one will have of the nature of vulnerability. As food systems incorporate both ecological and social elements, it is important to clarify the differences between social and ecological approaches to vulnerability. Social approaches focus on human welfare and livelihood strategies, stressing that social vulnerability is a function of inequity, and embedded in social, economic, and political structures (Ericksen et al. 2010). They have only recently incorporated a systems perspective. Ecological vulnerability approaches have focused more on the functioning of ecosystems and tradeoffs among ecosystems services. Human modification of ecosystems is the major reason for deterioration in ecosystems. With the prominence of ideas around coupled social-ecological systems (Berkes and Folke 1998) and research on global environmental change, the importance of functioning ecosystems for human wellbeing has emerged as a key research area. It is clear that for some key ecosystem services (nutrient cycling and climate regulation), we may be near to “planetary boundaries” (Rockstrom et al. 2009) that once crossed will cause significant harm to human welfare. Ecological approaches are concerned with identifying “tipping points,” or thresholds beyond which systems “flip” into a different state. While these approaches have helped us to better understand the interactions among social and ecological systems, the concept of ecological resilience needs rethinking in order to combine it with the framings of social vulnerability rooted in human geography, political economy, and sociology (Davidson 2010; Berkes and Ross 2013). Multiple stresses arising from global environmental change affect food systems and food security. As Misselhorn et al. (2010) explain, we need therefore to understand not only the impacts of individual drivers of change but also the interactions among these. Such a systemic analysis raises questions of temporal

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and spatial scale, extremes and predictability, and change and reversibility. Environmental change operates over both short and longer time as well as spatial scales, and food insecurity has temporal dimensions and is conditioned by local and global factors. In an increasingly interconnected food system and given the uncertainty about the direction and nature of some types of global environmental change, predictability of extremes is also a concern. Finally, a growing understanding of systems as nonlinear raises the concern of tipping points that are not reversible. Analyses of how and why people are food insecure fit very well with social framings of vulnerability. Since Sen’s influential writings (1981), the notion of economic and social entitlements to food has become embedded in the literature and writings on the political nature of famine (Devereux 2000, 2009) have further refined the food security lens. A household’s food security status is a function not only of how much food is produced but what the household can afford to buy, how well markets work, the gender of the household head, the impact of conflict, etc. However, trying to understand how global environmental change will affect food systems, and hence food security, is more challenging. Most work to date has looked at how food availability, or more narrowly agricultural production, will be affected by environmental changes such as temperature increases, shifts in nutrient cycles, and loss of biodiversity. More recent work has started to understand that agricultural incomes might be affected, with a subsequent impact on affordability of food and rural livelihoods more generally (Morton 2007). However, Eakin (2010) challenges analysis to move beyond place-based analyses to look more broadly at how food systems function globally, with cross-scale linkages. She argues that limiting analysis to the vulnerability of individual elements of a food system misses an understanding of how “vulnerabilities are produced, exacerbated or mitigated through synergistic or antagonistic interaction of different food system elements and actors across spatial and temporal scales (p. 79)”. For example, global environmental change is creating new patterns of pathogen and disease distribution, which will have implications for food safety (FAO 2008). The lessons of 2008 have taught us how a combination of drought in one or more major food-producing countries, coupled with shifts in agricultural production and export restrictions, can create a rippling food crisis in multiple countries. Eakin thus argues that we need to look at indicators such as malnutrition, high food prices, or ecosystem degradation as evidence that the whole food systems have failed (is vulnerable), often as the result of structural characteristics.

Framing Adaptation in Food Systems The large body of literature about how to get vulnerability analysis “right” is worth our attention because of the need to urgently adapt food systems to current and future global environmental change, in order to ensure food security but also avoid negative feedbacks that exacerbate environmental degradation. Overly simplistic analyses focused only on agriculture or that ignore structural issues will lead at best to “quick fixes” and at worst to responses that result in maladaptation.

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References Adger WN (2006) Vulnerability. Glob Environ Chang 16(3):268–281 Berkes F, Folke C (1998) Linking social and ecological systems for resilience and sustainability. In: Berkes F, Folke C (eds) Linking social and ecological systems. Cambridge University Press, Cambridge, UK Berkes F, Ross H (2013) Community resilience: toward an integrated approach. Soc Nat Resour: Int J 26:5–20 Bohle HG (2001) Vulnerability and criticality: perspectives from social geography. IHDP Update, 2 Davidson DJ (2010) The applicability of the concept of resilience to social systems: some sources of optimism and nagging doubts. Soc Nat Resour: Int J 23(12):1135–1149 Devereux S, (2000) Famine in the twentieth century. IDS working paper 105. University of Sussex, Brighton Devereux S (2009) Why does famine persist in Africa? Food Secur 1:25–35 Eakin H (2010) What is vulnerable? Chapter 6. In: Ingram J, Ericksen P, Livererman D (eds) Food security and global environmental change. Earthscan, London/Washington, DC, pp 78–86 Ericksen PJ (2008a) Conceptualizing food systems for global environmental change research. Glob Environ Chang 18:234–245 Ericksen PJ, (2008b) What is the vulnerability of a food system to global environmental change? Ecol Soc 13(2) Ericksen PJ, Bohle HG, Stewart B (2010) Vulnerability and resilience of food systems. Chapter 5. In: Ingram J, Ericksen P, Livererman D (eds) Food security and global environmental change. Earthscan, London/Washington, DC, pp 67–77 FAO (2008) Climate change: implications for food safety. FAO, Rome Misselhorn A, Eakin H, Devereux S, Drimie S, Msangi S, Simelton E, Stafford-Smith M (2010) Vulnerability to what? Chapter 7. In: Ingram J, Ericksen P, Livererman D (eds) Food security and global environmental change. Earthscan, London/Washington, DC, pp 87–114 Morton JF (2007) The impact of climate change on smallholder and subsistence agriculture. Proc Natl Acad Sci USA 104(50):19680–19685 O’Brien K, Eriksen S, Nygaard LP, Schjolden A (2007) Why different interpretations of vulnerability matter in climate change discourses. Clim Pol 7(1):73–88 Rockstrom J, Steffen W, Noone K, Persson AF, Stuart Chapin I, Lambin EF, Lenton TM, Scheffer M, Folke C, Scheenhuber HJ, Nykvist B, de Wit CA, Hughes T, van der Leeuw S, Rodhe H, Sorlin S, Snyder PK, Costanza R, Svendin U, Falkenmark M, Karlberg L, Corell RW, FAbry VJ, Hansen J, Walker B, Liverman D, Richardson K, Crutzen P, Foley JA (2009) A safe operating space for humanity. Nature 461:472–475 Sen A (1981) Poverty and famines: an essay on entitlement and deprivation. Clarendon, Oxford

Impacts of Climate Change on Food Availability: Agriculture

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€ller Christoph Mu

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Climate Change and Agricultural Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Direct Impacts of Climate Change on Plant Growth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Indirect Impact of Climate Change on Plant Growth Through Plant-Soil Interaction . . . . . . . Climate Change and Atmospheric Composition Effects on Agricultural Productivity . . . . . . . Implications for Food Availability Under Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Keywords

Plant growth • Photosynthesis • Fertilization • Resources • Extremes • Adaptation • Management

Definition Agricultural production, in terms of amount of food produced, is the most important constituent of the food availability component of food security. Agricultural production is directly and indirectly dependent on weather conditions. Climate change thus constitutes a major challenge to agriculture, leading not only to higher temperatures but also affecting timing and amount of precipitation, seasonalities, and extremes. Direct impacts on agriculture cover various plant growth processes that are affected by temperatures, water availability, energy inputs (sunlight),

C. M€uller Potsdam Institute for Climate Impact Research, Potsdam, Germany e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_133, # Springer Science+Business Media Dordrecht 2014

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and atmospheric CO2 concentrations. Indirect effects include processes in the soil and interaction with other plants, animals, and pests and diseases. In this section, we will address both the direct impacts of climate change on plant growth and the indirect impacts through plant-soil interactions.

Climate Change and Agricultural Production Agricultural Production is directly dependent on weather conditions, which determine, together with soil conditions, the environment for plant growth. Plants, as primary producers, produce biomass for direct human consumption (e.g., cereals, fruits, beets) or for animal feed for meat, eggs, or milk production. They also supply biomass for energy production (e.g., ethanol from sugarcane or bio-diesel from rapeseed), fibers for textiles (e.g., cotton), and various other materials (e.g., starch-based plastic). Many of the environmental conditions of soil and weather can be managed, such as irrigation water can compensate deficient rainfall, manure and artificial fertilizers can supplement depleted nutrients in the soil. In the most extreme, agricultural production can be relocated to multi-story greenhouses with artificial lights. Each management option comes at a price and/or new environmental impacts, and as long as food prices do not multiply (or energy prices dwindle), intense management of temperatures and light will be constrained to high-value crops; irrigation will be constrained to areas where yields can be strongly increased and water is sufficiently easily accessible, while nutrient management is central in agriculture to refill exported nutrients at harvest. Agriculture thus is and will be dependent on weather conditions and consequently is subject to impacts from climate change.

Direct Impacts of Climate Change on Plant Growth Photosynthesis is the central process of plant growth which is the conversion of atmospheric carbon dioxide to sugar with the help of energy from sunlight. The sugars are the energy storage of the plant for all energy-requiring processes, such as the formation of more complex molecules, plant growth, and maintenance. About half of the energy stored in the sugars from photosynthesis is used for the plant’s own energy demand, while the other half is stored in the biomass of the plant. The chemical processes of the photosynthesis are directly and indirectly affected by weather conditions as well as atmospheric carbon dioxide concentrations. The chemical processes work best at specific temperature ranges and slows down considerably at low or high temperatures. Here, global warming can be both beneficial and damaging to photosynthesis if temperatures move further into or out of the optimal temperature range. The carbon dioxide that is taken up from the surrounding air and which supplies the carbon for the sugar synthesis enters the plant through small pores on the leaves (stomata) through which the plant also transpires water. The water status of the plant determines to which degree these stomata are opened and thus how much carbon can be acquired and how much

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water is lost. Here, water availability from precipitation mediated through the soil strongly affects the photosynthesis rate. High temperatures and radiation (sunlight) also determine the plant’s tendency to wilt under given water supplies so that climate change affects the carbon and water exchange between plants and the atmosphere via changes in precipitation, temperature, and radiation (e.g., cloudiness and transmissivity of the atmosphere). Phenology describes the life cycle of plants from emergence of the seedling to maturity and harvest. The different phenological stages are important for the final formation of yields, and they are sensitive to weather conditions. As such, the number of grain kernels in a cereal is determined quite early in the life cycle, long before the plant shows flowers or ears and it reflects growing conditions (e.g., dry vs. moist) during that phase. Flowering is a relatively short period of the plant’s life cycle, but it is especially sensitive to high temperatures, which can lead to sterility of the flowers and thus no fruit formation. The length of the life cycle is also mainly determined by air temperature. At higher temperatures, the life cycle of plants is accelerated, which means that the plant reaches maturity faster and thus has less time to grow and form yield. In cereals, the time span between flowering and maturity often determines the size of grain kernels. Rising temperatures, independent of associated changes in precipitation, thus typically lead to reductions in yield if not compensated by changes in management (e.g., earlier sowing dates, cultivation of different varieties). Allocation of newly acquired biomass in photosynthesis to the different plant organs (roots, leaves etc.) is another process that is sensitive to weather conditions. During early stages of the plant’s life cycle, newly formed biomass is mainly used for elongation of roots and expansion of leaf area. Root growth is needed to access soil water and nutrients, which is central to growth. The leaf area determines the amount of intercepted light energy, which fuels photosynthesis and thus allows for further growth. Water stress during early stages of the life cycle can lead to intensified growth of roots, typically at the expense of leaves. A better developed root system can lead to higher robustness against deficiencies in water availability in later stages, as plants can exploit deeper soil water reservoirs. The tradeoff with leaf growth, however, only pays off, if there are repeated phases of water deficiencies, as the reduced leaf area would lead to lower photosynthesis rates and thus plant growth. Extremes in temperatures or precipitation are also subject to increase in frequency and intensity under climate change. Extremely high temperatures, which are often correlated with drought conditions, can lead to sterility of plants, permanent damage to plant tissue, and permanent wilting and consequently pre-mature death. Extremely low temperatures are less likely under climate change, even though changes in circulation patterns can also lead to more frequent frost events in some locations. Extreme precipitation can be severely damaging both at the low and high end. Whereas low precipitation leads to drought conditions which can be managed to some extent with supplementary irrigation or cultivation of drought-resistant crops, extreme high precipitation events can lead to extreme damage within minutes, such as during hail storms. Such events cannot be managed in the production system but are typically of limited spatial extent.

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Indirect Impact of Climate Change on Plant Growth Through Plant-Soil Interaction Soil water is the water reservoir available to plants and thus directly affects plant growth. Just like any other reservoir, soils store water over a period of time and the plant available water is determined by the balance of inputs and outputs. Not all water from precipitation or irrigation enters the soil, but some water is intercepted by the canopy and directly evaporates from there back to the atmosphere. Under intense rainfall, extensive irrigation, or snow melt, not all water that reaches the soil surface can infiltrate into the soil. Water that cannot infiltrate forms surface runoff and reaches rivers and lakes or infiltrates elsewhere. Such surface runoff can cause severe erosion of soils. The infiltration rate is determined by the substrate of the soil (coarse vs. finer materials), pore structures, compaction (e.g., from heavy machinery like tractors), surface seals, and crusts. The infiltrated water percolates through the soil layers until it reaches an impermeable layer, above which it forms groundwater deposits of sub-surface runoff. The physical properties of soils can keep water from further percolation to deeper layers, which prolongs the availability of water to plants after input (e.g., rainfall, irrigation). If upper layers dry, water can even be transported upward again by capillary rise. How much water can be stored in soils is dependent on the grain size mixture of the soil and the structure and amount of soil organic matter. The plant available soil water is transported back to the atmosphere either by plant transpiration, or evaporation from the soil surface. Transpiration is the only productive water flux out of the soil, as the flux from the soil through the roots and leaves into the atmosphere supplies the plant with water and determines to which extent the small pores on the leaves (stomata) can be opened for uptake of carbon dioxide for photosynthesis. Evaporation, interception, and runoff are unproductive water fluxes from the water budget available to plants. These fluxes can be minimized by management such as drip irrigation versus sprinkler to reduce interception, or soil cultivation to allow for improved infiltration and reduced evaporation. Climate change does not only affect the input from precipitation, but also the energy available for evaporation of water. Under higher temperatures and higher radiation (e.g., less cloud cover), more energy is available to convert liquid water to water vapor, which accelerates evaporation fluxes as well as transpiration fluxes through the plant. If evaporation energy exceeds the amount of plant available water or the plants’ physical ability to transport water, the plant experiences water stress. As a consequence, stomata have to be closed and photosynthesis is reduced. Nutrients are supplied to plants mainly in form of water-soluble cations. They stem from either inorganic compounds in artificial fertilizers or from microbemediated decomposition of soil organic matter (Bouwman et al. 2009). Soil organic matter is formed from dead biomass such as old leaves and plant residues (roots, straw, etc.) as well as manure applied to the field as fertilizer. The decomposition of soil organic matter, and thus the liberation of plant nutrients, is determined by microbe activity. Microbe activity in turn is determined by the availability and quality of organic matter on which they feed as well as temperature and moisture. Under global warming, microbe activity is typically enhanced owing to the higher temperatures.

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Changes in precipitation and thus water availability can both inhibit and enhance microbe activity. Their activity, and thus decomposition rates of soil organic matter, is inhibited if there is too little water or so much that soil become anoxic. Increased decomposition in fallow periods and increased rainfalls can also lead to higher leaching rates, i.e., the washing away of nutrients with percolation and runoff. Degradation of soils constitutes a reduction of soil productivity, i.e., the suitability for agricultural production (Lal 2009). Soil degradation is driven by various mechanisms relevant to climate change. Soil erosion is largely determined by precipitation intensity and wind speed as well as management options taken to prevent it (contour tillage, mulching, no-till, windbreak, etc.). Changes in precipitation amounts and timing, changing groundwater tables, sea level rise as well as irrigation can also lead to salinization of soils, which can lead to total loss of agricultural productivity.

Climate Change and Atmospheric Composition Effects on Agricultural Productivity Carbon dioxide is the most prominent greenhouse gas. The anthropogenic emissions of carbon dioxide and other greenhouse gases such as methane and nitrous oxide to the atmosphere drive climate change. Whereas methane and nitrous oxide are mainly emitted from agricultural production, carbon dioxide is emitted mostly from the energy and transport sectors. Carbon dioxide does not only drive anthropogenic climate change, but also directly affects plant growth and thus agricultural productivity. Photosynthetic rates of most plants are limited by the atmospheric carbon dioxide concentrations, and rising carbon dioxide concentrations in the atmosphere due to anthropogenic emissions can thus gradually lift this limitation. The group of plants that experience such direct stimulation of photosynthesis under elevated atmospheric carbon dioxide concentrations is referred to as C3 plants, because their primary photosynthetic product is a three-carbon sugar. Prominent representatives of this group are wheat, rice, and soybean. Some plants, referred to as C4 plants, have developed a mechanism to decouple the fixation of carbon dioxide from photosynthesis and are thus less limited by ambient carbon dioxide concentrations. The group of C4 plants includes some important agricultural crops, such as maize, sugarcane, millet, and sorghum. Both C3 and C4 plants in semiarid and arid environments profit from elevated atmospheric carbon dioxide concentrations, because stomata can be closed more often to save water without reducing the influx of carbon for photosynthesis. The beneficial effects of elevated atmospheric carbon dioxide concentrations on photosynthesis and plant growth have been demonstrated in laboratory, open-chamber field trials, and free air carbon dioxide enrichment experiments (FACE). However, there is still large uncertainty on the general effects at larger scales and for longer time horizons. Increased plant growth under elevated atmospheric carbon dioxide concentrations will have to be accompanied by adjustments in fertilization, and it is not granted that current varieties can transform the gains in photosynthesis and biomass also in gains in yield (e.g., grains) (Leakey et al. 2009).

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An increase in biomass and yield may be associated with a decrease in protein concentration and thus in nutrient quality and economic profitability. Altered chemical composition of plant tissues under elevated carbon dioxide concentrations was also shown to change the plants’ susceptibility to insect damage and may require intensified crop management to avoid losses (Zavala et al. 2008). Atmospheric composition changes also with respect to other gases and aerosols from anthropogenic emissions. These also affect plant growth and are thus relevant to agricultural production. Most important are nitric oxide and nitrogen dioxide jointly referred to as NOx. NOx are important precursors of ozone and is a source of reactive nitrogen to soils, because NOx reacts with water to nitric acid in the atmosphere and is then deposited by rainfall in soils and can be absorbed by plants. Near-surface ozone on the other hand is harmful to plants because of its oxidizing capacity. Ozone enters plants through the stomata and damages cells and tissue there through oxidation, causing reduced photosynthesis, pre-mature leaf loss, and reduced biomass (Bender and Weigel 2011).

Implications for Food Availability Under Climate Change Future climate change is subject to massive uncertainties, which most prominently start with the inability to predict future energy consumption and climate policies. The upper end of global mean temperature rise as summarized in the fifth assessment report of the Intergovernmental Panel on Climate Change (IPCC) report reaches 4.1+/ 0.5  C by 2100. It is noteworthy that temperature rise over land is more pronounced than global mean temperature rise as temperatures above oceans rise more slowly. Also, temperatures tend to rise stronger in higher latitudes than in the tropics, a phenomenon referred to as “polar amplification.” Current agricultural areas are thus bound to experience significant increases in temperatures, even if effective climate policy is enforced in the future. On top of rising temperatures under climate change, precipitation patterns, cloudiness, and extreme events are expected to change. However, these aspects are much more difficult to project than global mean temperature and uncertainties associated with these changes are thus much higher, especially at temporal and spatial resolutions relevant to agriculture (Hawkins and Sutton 2011). Given additional uncertainties on management, effectiveness of carbon dioxide fertilization, and indirect impacts such as the availability of freshwater for irrigation, assessments of climate change impacts on agricultural production are inherently uncertain. Studies on future climate change impact thus cannot answer the question on how agricultural production will perform in the future, but they can help to understand risks and opportunities and to identify suitable adaptation measures. Despite this discouraging dominance of uncertainties, there are some very robust conclusions and insights that also facilitate policy-making and planning. Most importantly, there are no climate impact studies on agriculture that rule out negative impacts of climate change on agricultural productivity. Climate change is clearly a risk for agricultural production. A recent consolidated study on global climate change impact on agriculture finds climate change impacts on crop yields for

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a high-emission scenario to range between 20 % and 45 % for maize, 5 % and 50 % for wheat, 20 % and 30 % for rice, and between 30 % and 60 % for soybean by 2100. The effects of carbon dioxide fertilization, which are most pronounced under a high-emission scenario, can offset some of these impacts, which then range between 10 % and 35 % for maize, +5 % and 15 % for wheat, 5 % and 20 % for rice, and between 0 % and 30 % for soybean. If nitrogen is assumed to be non-limiting, climate change impacts are less severe and, in combination with carbon dioxide fertilization, yield could also increase (Rosenzweig et al. 2014). There are some important general conclusions to be made from global scale and individual site-based studies that are robust across a broad variety of climate scenarios, management assumptions, and locations. First of all, climate change impacts become worse with increasing temperatures, even though associated changes in precipitation can cause considerable variation to that. The more the planet warms, the larger will be the challenges to agricultural production and food availability. Secondly, there are important differences between tropical and temperate/boreal regions. Tropical regions, which incorporate many developing countries, will suffer already from small increases in temperature as current temperatures are already at the upper end of optimal temperatures for plant growth. Agriculture in regions in higher latitudes (and also higher altitudes) is often constrained by cold temperatures. Small increases in temperatures of 1–2  C are thus projected to be beneficial to agricultural productivity, while climate change impacts become negative at higher temperature increases. Third, agricultural management is not only a major determinant in the actual strength of climate change impacts on agricultural productivity, it also allows for multifaceted adaptation to changing environmental conditions. Some of these adaptation measures can be easily implemented by farmers, such as adjustment of cropping seasons, while others may require targeted research and development, such as the breeding of new varieties, or massive economic investment, such as the expansion of infrastructure for irrigation. Here, tropical regions have considerable potential to increase agricultural productivity through improved management (Neumann et al. 2010). There are several additional aspects related to food availability under climate change that also require more attention in scientific studies. One important aspect is the availability of nutrients under climate change, which requires a better understanding of food quality, next to food quantities (Lloyd et al. 2011). Another aspect is the propagation of pests and diseases under climate change, which likely constitutes another pressure on agricultural production and will also require adjustments in agricultural management (Bebber et al. 2013).

References Bebber DP, Ramotowski MAT, Gurr SJ (2013) Crop pests and pathogens move polewards in a warming world. Nat Clim Change 3:985–988. doi:10.1038/nclimate1990 Bender J, Weigel HJ (2011) Changes in atmospheric chemistry and crop health: a review. Agron Sustain Dev 31:81–89. doi:10.1051/agro/2010013

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Bouwman AF, Beusen AHW, Billen G (2009) Human alteration of the global nitrogen and phosphorus soil balances for the period 1970–2050. Global Biogeochem Cycles 23, Gb0a04. doi:10.1029/2009gb003576 Hawkins E, Sutton R (2011) The potential to narrow uncertainty in projections of regional precipitation change. Climate Dynam 37:407–418. doi:10.1007/s00382-010-0810-6 Lal R (2009) Soil degradation as a reason for inadequate human nutrition. Food Secur 1:45–57. doi:10.1007/s12571-009-0009-z Leakey ADB, Ainsworth EA, Bernacchi CJ, Rogers A, Long SP, Ort DR (2009) Elevated CO2 effects on plant carbon, nitrogen, and water relations: six important lessons from FACE. J Exp Bot 60:2859–2876. doi:10.1093/jxb/erp096 Lloyd SJ, Kovats RS, Chalabi Z (2011) Climate change crop yields, and undernutrition: development of a model to quantify the impact of climate scenarios on child undernutrition. Environ Health Perspect 119:1817–1823. doi:10.1289/ehp.1003311 Neumann K, Verburg P, Stehfest E, M€ uller C (2010) A global analysis of the intensification potential for grain production. Agr Syst 103:316–326. doi:10.1016/j.agsy.2010.02.004 Rosenzweig C, Elliott J, Deryng D, Ruane AC, M€ uller C, Arneth A, Boote KJ, Folberth C, Glotter M, Khabarov N, Neumann K, Piontek F, Pugh TAM, Schmid E, Stehfest E, Yang H, Jones JW (2014) Assessing agricultural risks of climate change in the 21st century in a global gridded crop model intercomparison. Proc Natl Acad Sci USA. doi:10.1073/pnas.1222463110 Zavala JA, Casteel CL, DeLucia EH, Berenbaum MR (2008) Anthropogenic increase in carbon dioxide compromises plant defense against invasive insects. Proc Natl Acad Sci USA 105:5129–5133. doi:10.1073/pnas.0800568105

Additional Recommended Reading Boote KJ, Jones JW, White JW, Asseng S, Lizaso JI (2013) Putting mechanisms into crop production models. Plant Cell Environ 36:1658–1672. doi:10.1111/pce.12119 Challinor AJ, Ewert F, Arnold S, Simelton E, Fraser E (2009) Crops and climate change: progress, trends, and challenges in simulating impacts and informing adaptation. J Exp Bot 60:2775–2789. doi:10.1093/jxb/erp062 M€ uller C (2013) African lessons on climate change risks for agriculture. Annu Rev Nutr 33:395–411. doi:10.1146/annurev-nutr-071812-161121 Rosenzweig C, Hillel D (eds) (2010) Handbook of climate change and agroecosystems: impacts, adaptation, and mitigation. Imperial College Press, London, 452 pp

Impacts of Climate Change on Food Availability: Livestock

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Feliu Lopez-i-Gelats

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Relevance of Livestock in a World of Demographic Growth and Rising Climatic Uncertainties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Impact of Climate Change on Livestock Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Contribution to Food Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

The existing difficulties of the livestock sector to meet the growing food demand in a rising population world under climate uncertainties are uncontested. However, little work has been done until now considering that multiple ways of conducting livestock farming coexist. This paper briefly examines how climate change affects differently different livestock farming systems – namely, grazing, mixed farming, and non-grazing systems – and the dissimilar implications of this on food security. Keywords

Impact • Grazing systems • Mixed systems • Non-grazing systems • Food security

F. Lopez-i-Gelats Center for Agro-food Economy and Development (CREDA-UPC-IRTA), Castelldefels, Barcelona, Spain e-mail: [email protected]; [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_118, # Springer Science+Business Media Dordrecht 2014

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Definition This paper warns against generalizations on the basis that different livestock farming systems entail divergent interactions between livestock, climate change, and food security.

Relevance of Livestock in a World of Demographic Growth and Rising Climatic Uncertainties It is estimated that in 2050, there will be nine billion people to feed. The expanded population is expected to consume almost twice the animal source food that is consumed today. According to Steinfeld et al. (2006), meeting this projected demand would require a remarkable growth in livestock raising, namely, 158 % in beef, 178 % in lamb, 137 % in pork, 225 % in poultry, and 158 % in dairy produce. Satisfying this demand would be highly challenging, particularly in the current context of increasing climate uncertainty and shock and specifically if it is kept in mind that a similar effort has already been accomplished in the last decades. From 1967 to 2007 the production of meat per person has increased by 152 % in pork, 93 % in beef, 183 % in eggs, 92 % in milk, 369 % in poultry, and 105 % in lamb (FAO 2009). Certainly livestock farming deploys a crucial role in securing the world food provision. Nevertheless, livestock fulfills many other roles besides food production, such as draught power, fertilization, household fuel, fiber, wealth storage, social status, cultural identity, control of insects and weeds, and a buffer against crop failure. However, the astonishing performance of livestock goes with an equally astonishing voracity of natural resources. Thus, for instance, the livestock sector accounts for 80 % of the agricultural land, with 26 % of the world’s ice-free terrestrial area being devoted to pasture and 33 % of cropland being used for feed crop production; 8 % of human water use, mostly for irrigation of feed crops; and 58 % of the directly used human-appropriated biomass (Krausmann et al. 2008). This also goes with remarkable greenhouse gas emission. The livestock sector is estimated to contribute to 14 % of anthropogenic emissions – 18 % if land use change and deforestation are considered (Steinfeld et al. 2006). Goodland and Anhang (2009) suggest this is an underestimated figure. They determine that the contribution of the livestock sector is 51 % of total greenhouse gas emission. Climate change pushes livestock farming towards a new era of augmented uncertainties and shocks (Rahmstorf et al. 2007). The emissions of the major greenhouse gases are continuing to increase (Raupach et al. 2007). However, for years this consideration has been out of the policy and research agenda. But the discussions in and after the 2009 United Nations Framework Convention on Climate Change in Copenhagen and the publication of studies showing both the effects of livestock on climate change and the effects of climate change on livestock farming have increased the interest on the connections between climate

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variability and change and the livestock sector (Steinfeld et al. 2006). However, little work has been conducted considering that an immense diversity of livestock farming practices exists. Only few attempts have tackled the issue of climate change and livestock by differentiating among grazing and landless industrial livestock farming (Rivera-Ferre and Lo´pez-i-Gelats 2012). As follows, it is briefly examined how climate change affects differently different livestock farming systems – namely, grazing, mixed farming, and non-grazing systems – and the dissimilar implications of this on food availability.

Impact of Climate Change on Livestock Production Several are the difficulties that have to be borne in mind when identifying and attributing climate-change-related impacts to livestock: (a) the distinction between climate change and climate variability; (b) generally the impacts tend to be considered in the context of extreme events, and incremental variations of climate parameters should also be taken into consideration; and (c) the impacts are of a complex causality. As noted by Morton (2007), these difficulties become even more numerous when dealing with small-scale livestock farming as a consequence of the following: (d) the lack of standardized definitions of these systems and therefore of standard data above the national level; (e) the intrinsic characteristics of these systems, particularly their complexity, their location specificity, and their integration of agricultural and nonagricultural livelihood strategies; and finally (f) their exposure to non-climate stressors. In order to better understand the varied and complex nature of climate change impacts on livestock, two classifications can be done: firstly, considering the nature of the climate alteration, it can be distinguished between: (a) extreme events, such as floods, hurricanes, droughts and heat waves, and (b) incremental changes of climate parameters, such as rise in global temperature, glacial retreat, decreasing snowcap, sea level rise, and higher atmospheric concentrations of CO2; and, secondly, considering the nature of the causality of the impact, it can be distinguished between (c) direct impacts, such as heat stress, water stress, and destruction of livestock farming infrastructures, and (d) indirect impacts, such as modification in the geographical distribution of vector-borne diseases and reduction in the quantity and quality of feeding. Table 79.1 summarizes the main impacts that the different livestock systems are expected to undergo the most. Obviously, not all systems will suffer equally. In non-grazing systems, characterized by the confinement of the animals, the main impacts are expected to be indirect and leading to face rising water, feeding, and housing costs. The most relevant direct impact they have to deal with is the destruction of infrastructure due to extreme events. The main weakness of these

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Table 79.1 Impacts of climate change on livestock farming systems

Direct impact

Grazing systems (pastoralism; scavenging) Incremental Temperature stress change Water stress Extreme event

Soil erosion Livestock casualties Indirect Incremental Variation of the impact change quality and quantity of pasture Better conditions for livestock disease Decrease productivity of livestock Extreme Pasture shortage event

Mixed systems (rain-fed mixed farming; irrigated mixed farming intensive grazing) Temperature stress Water stress

Non-grazing systems (landless industrial production) Increased cost of animal housing (e.g., cooling. . .) Destruction of infrastructures

Destruction of infrastructures Soil erosion Variation of the quality and Disease epidemics quantity of fodder Increase cost of feed Better conditions for and water livestock disease Better conditions for crop pests Decrease productivity of livestock Fodder shortage

Increased transport cost Increased cost of feed and water

systems stems from the fact that they are not able to move. Climate change forces them to spend more and more resources to isolate the animals from the outside climate variability. The main impacts affecting mixed farming systems entail a decrease in the productivity of crops and thus of animal feeding availability. Also, irrigated mixed farming is particularly exposed to the destruction of infrastructures by extreme weather events. When climate change impacts entail alterations in the ecosystems, grazing systems are more prone to suffer from it. Ostensibly, grazing systems will have to tackle with decreasing rangeland productivity. This will certainly lead towards overgrazing and land degradation if farmers are not able to move. The role of non-climate stressors on their capacity to move is crucial here.

Contribution to Food Security To examine the contribution to food security of the livestock sector, it is again illustrative to distinguish among the different livestock farming systems and the geographical spaces they occupy. Pastoralism is located in lands that are too wet, dry, mountainous, distant, or stony for cultivation; the scavenging systems in backyards in villages; intensive grazing where high-quality grassland and fodder production can support larger numbers of animals; rain-fed and irrigated

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mixed farming near sources of crops and by-products; and finally landless industrial systems near large urban centers. The strategies to produce edible animal source food are plainly dissimilar: (a) grazing and scavenging, (b) livestock and agriculture integration, and (c) speculation and capital mobility. Grazing and scavenging systems convert human-inedible food, particularly pasture, browse, and residues, into edible animal source food. Mixed farming systems convert human-inedible self-produced crop residues into edible animal source food. Landless industrial production systems convert human-edible purchased products, mostly grains and industrial by-products, into edible animal source food. The consequences are clearly visible in the ratio of output and input of edible protein. While it is high in pastoralist regions (e.g., Kenya, 21.16; Mongolia, 14.60) and lower in intensive grazing regions (e.g., New Zealand, 10.06), it falls below one in landless industrial production regions (e.g., Brazil, 1.17; Germany, 0.62; USA, 0.53). Unfortunately the annual growth rate of the livestock systems is inversely proportional to their performance in this ratio, that is, 0.7 %, 2.2 %, and 4.3 % (Sere´ and Steinfeld 1996).

Conclusions In order to better understand the impacts of climate change on the livestock sector and the subsequent implications of this on food availability, unraveling the specific contributions and impacts for the different livestock farming systems helps to shed light on the existing interactions. Generalizations on the livestock-climatepopulation interactions should be skipped on the basis that livestock farming systems are diverse.

References Food and Agriculture Organisation (FAO) (2009) Food security and agricultural mitigation in developing countries: options for capturing synergies. FAO, Rome Goodland R, Anhang J (2009) Livestock and climate change. What if the key actors in climate change were pigs, chickens and cows? Worldwatch Institute, Washington, DC, pp 10–19 Krausmann F, Erb KH, Gingrich S, Lauk C, Haberl H (2008) Global patterns of socioeconomic biomass flows in the year 2000: a comprehensive assessment of supply, consumption and constraints. Ecol Econ 65:471–487 Morton JF (2007) The impact of climate change on smallholder and subsistence agriculture. PNAS 104:19680–19685 Rahmstorf S, Cazenave A, Church JA, Hansen JE, Keeling RF, Parker DE, Somerville RCJ (2007) Recent climate observations compared to projections. Science 316:709 Raupach MR, Marland G, Giais P, Le Quere C, Canadell JG, Klepper G, Field CB (2007) Global and regional drivers of accelerating CO2 emissions. PNAS 104:10288–10293

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Rivera-Ferre MG, Lo´pez-i-Gelats F (2012) The role of small scale livestock farming in climate change and food security. VSF-Belgium, SIVTRO, AVSF and VSF-CZ, Barcelona, 138 p Sere´ C, Steinfeld H (1996) World livestock production systems: current status, issues and trends, FAO animal Production and Health Paper 127. FAO, Rome Steinfeld H, Gerber P, Wassenaar T, Castel V, Rosales M, de Haan C (2006) Livestock’s long shadow: environmental issues and options. FAO, Rome

Impacts of Climate Change on Food Availability: Non-Timber Forest Products

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Sheona Shackleton

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Direct Contribution of NTFPs to Food Security: Wild Foods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Indirect Contribution of NTFPs to Food Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Climate Change Interactions, Impacts, and Other Threats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Across the developing world, wild foods hunted or gathered from forests and other natural or modified ecosystems are vital for supplementing agricultural production by contributing to improved food availability and quality. These supplementary and alternative sources of food, often referred to as non-timber forest products (NTFPs), are especially crucial in years of crop failure – usually the result of extreme climatic events (droughts and floods), disease and pest outbreaks and other natural disasters. Trade in a wide range of NTFPs can provide a source of income that allows the purchase of food for both dietary diversification and to supplement calorie intake in periods of shortage, indirectly contributing to food security. Such increased consumption and use of NTFPs in times of stress can be viewed as an effective autonomous coping mechanism for dealing with threats to food security and is likely to expand under predicted climate change. Yet, we know little about how climate change, interacting with other drivers of change, will impact the world’s forests and woodlands and, more particularly, the range of products that people rely on. Limited research has been undertaken to consider how changes in climate may affect the distribution,

S. Shackleton Department of Environmental Science, Rhodes University, Grahamstown, South Africa e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_117, # Springer Science+Business Media Dordrecht 2014

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productivity or availability of the wild species that people use for food and other purposes. More research is required at the interface between food security and the ecosystem services provided forests, woodlands and associated ecosystems, and the linkages to agriculture and climate change. It is necessary to look beyond the farm and conventional crops to the wide variety of foods people obtain from their environment. Keywords

Non-timber forest products • Food security • Wild foods • Climate change • Vulnerability

Definition Non-timber forest products: There is much debate around what constitutes an NTFP. The definition used in this chapter draws on the intuitive and widely accepted definition of De Beer and McDermott (1989) and recognises NTFPs to include all biological materials other than timber extracted from wooded systems for local livelihood benefit. In line with this definition, NTFPs can include floral products such as grasses, roots, flowers, fruits, and bamboo, which people use for a variety of purposes (e.g., as food for themselves and their domesticated animals, as medicinal plants, as ornaments, and as raw material for tools), as well as faunal products such as insects, birds, fish, or game.

Direct Contribution of NTFPs to Food Security: Wild Foods Across the developing world, wild foods hunted or gathered from forests and other natural or modified ecosystems are vital for supplementing agricultural production by contributing to improved food availability and, more especially, food quality (Shackleton et al. 2011). It is estimated that close to one billion people in the world rely to some extent on wild foods (Aberoumand 2009). These include plant products such as fruits, green leafy vegetables, woody foliage, bulbs and tubers, cereals and grains, nuts and kernels, and saps and gums which may be eaten or used to make wine; fungi; invertebrates including insects, crustaceans, snails and products like honey; birds and bird eggs; bushmeat from small and large mammals; and reptiles and fish (Shackleton et al. 2010), and involve thousands of different species. These non-timber forest products (NTFPs) can form a significant portion of the diet of rural households as well as play a role in expanding dietary diversity and ensuring a more nutritious and balanced diet (Table 80.1). Many wild foods are rich in minerals and vitamins (Grosskinsky 2000), and animal-based products, whether bushmeat or insects, often add much needed protein to the diet (Table 80.1). Women and girls are often the primary collectors of wild plant foods, while men and boys do the hunting and fishing. These divided gender roles are also often reflected in the consumption of these foods (Heubes et al. 2012).

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Table 80.1 Some examples illustrating the importance of wild foods in the diet and their increased consumption in times of crisis and crop failure Example Importance in the diet Zambia – the wide variety of wild foods (e.g., mushrooms, fruits, leafy vegetables, tubers, edible insects, and honey) from Zambia’s Miombo woodlands greatly enrich the primarily starch-based diet of local people and improve food security South Africa – wild foods were found to form as much as 50 % of the diet of a third of poor children (850) surveyed in the Eastern Cape West and Central Africa – bushmeat provides around 25 % of protein requirements and up to 100 % for some indigenous groups. Amounts harvested are significant, with the annual harvest of bushmeat in the Congo Basin estimated to exceed 2 million tonnes per annum Eritrea – in the Gash-Barka administrative zone, people rated wild foods as the most important ecosystem service from riverine forest Namibia – in Caprivi wild foods provide up to 50 % of household subsistance during the nonagricultural season Increased consumption during hard times Venezuela – Yanomami Indians regularly use 20 wild plant species in their diets, but when they are faced with food shortages, they consume an additional 20 species which they do not use during normal times Botswana – when there is crop failure due to drought, wild fruits provide a fallback for households to use until conditions improve Zimbabwe – in difficult years poor rural households increase the quantities of wild fruits they consume and sell to generate income for household food expenditure

Source Jumbe et al. (2008)

McGarry and Shackleton (2009) Bennett and Robinson (2000); Fa et al. (2003)

Araia (2005)

Ashley and LaFranchi (1997)

Fentahun and Hager (2009)

Mojeremane and Tshwenyane (2004) Mitho¨fer and Waibel (2004)

As well as everyday consumption, such supplementary and alternative sources of food are critical as a safety net in crisis years when food supply is limited due to crop failure, often the result of extreme climatic events (droughts and floods), disease and pest outbreaks, and other natural disasters (Takasaki 2011; Vo¨lker and Waibel 2010; Nkem et al. 2010). The term “famine food” effectively captures this idea and refers to wild foods eaten mainly under conditions of severe drought (Guinand and Lemessa 2001; Oluoch et al. 2009). Such increased consumption of NTFPs in times of stress can thus be viewed as an effective autonomous coping mechanism for dealing with threats to food security (Table 80.1).

Indirect Contribution of NTFPs to Food Security In addition to the use of wild foods in the diet, these and other NTFPs can contribute indirectly to food security by providing an opportunity for bartering (exchange for

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food) or for earning cash income through the sale of products locally or in more distant markets (Mitho¨fer and Waibel 2004; Shackleton et al. 2011; Shackleton and Shackleton 2011; Heubes et al. 2012). This income is then used to purchase food that is not locally available or to stock up on staples during periods of scarcity. Like the consumption of wild foods, the sale of NTFPs also often increases in crisis periods as a means to cope with adversity and mitigate against food insecurity (McSweeney 2005). However, there is a risk that growing markets and increasing commercial trade could threaten subsistence and fallback supplies in the future (Nkem et al. 2010). Forest products are also important in various aspects of food sourcing and production, for example, in providing wood for the construction of canoes for fishing, tools for hunting and cropping, and energy for cooking as well as forage for livestock production (Shackleton et al. 2011). Without these NTFPs people’s health and well-being would suffer.

Climate Change Interactions, Impacts, and Other Threats Given the above discussion, it could be expected that under predicted climate change, particularly the increase in frequency and intensity of extreme events, the likelihood of people resorting to consuming wild foods and the sale of NTFPs as a coping strategy may expand (Shackleton et al. 2010). Yet, we know little about how climate change, interacting with other drivers of change will impact the world’s forests and woodlands and, more particularly, the range of products that people rely on from these forests (e.g., Nkem et al. 2010). It is possible that dry forests will be more severely impacted than tropical forests, worsening food security in the already vulnerable arid and semiarid regions. Limited research has been undertaken to consider how changes in climate may affect the distribution, productivity, or even continued existence of the wild species that people use for food or a multitude of other purposes. An exception that could provide an example for future studies is the recent work by Heubes et al. (2012). This paper considers the impact of climate change on the incomes earned from three important food and export species in Benin, West Africa (Adansonia digitata (baobab), Parkia biglobosa and Vitellaria paradoxa (shea)). The authors used local surveys to map the economic value of these species at the scale of their distribution and assessed this against the species’ current and future occurrence probabilities using nichebased models. They found that up to 50 % of the current economic value may be lost by 2050 due to the impacts of climate change. Recognizing the potential impacts of a changing climate and the scenario of possible increasing reliance on forest natural safety nets as agricultural production is impacted by changing weather patterns (Osbahr et al. 2008; Nkem et al. 2010), there is a need to understand how the consequent increased pressure on these resources might affect their resilience to climate change (Shackleton and Shackleton 2012). Could the combination of climate change and heavy harvesting put people and the ecosystems they rely on into a situation of escalating vulnerability? Could this potential downward spiral be worsened by global food security

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crises and rising food costs (Brown 2012) making the possibility of purchasing food out of the reach of poor people? Are forests likely to be transformed to increase agricultural production resulting in trade-offs between local and regional/national food security as widely available nutritious wild foods are replaced by conventional crops aimed at markets? What about biofuels and the impacts of logging on forest diversity? And what does this all mean for equity and social justice? These are just some of the questions that need to be asked. More research is required at the interface between food security and the ecosystem services provided by forests, woodlands and associated ecosystems, and the linkages to agriculture and climate change. It is necessary to look beyond the farm and conventional crops to the wide variety of foods people obtain from their environment. Furthermore, this should become embedded in national and regional climate change policies and strategies. The importance of forest products for coping and adaptation is an area that is often neglected, as illustrated for Burkina Faso (Kalame et al. 2011) and Cameroon (Bele et al. 2011). This gap needs attention if future food security is to be assured. In terms of REDD+ and mitigation, careful consideration is required regarding restrictions on forest access so as not to curtail traditional coping responses and to prevent direct impacts on poor people’s food security.

References Aberoumand A (2009) Nutritional evaluation of edible Portulaca oleracea as plant food. Food Anal Method 2:204–207 Araia MG (2005) Revealing the forest hidden value: the case study of Eritrea. Unpublished masters thesis, University of Stellenbosch, Stellenbosch Ashley C, LaFranchi C (1997) Livelihood strategies of rural households in Caprivi: implications for conservancies and natural resource management. Directorate of Environmental Affairs, Ministry of Environment and Tourism, Windhoek Bele MY, Somorin O, Sonwa DJ, Nkem J, Locatelli B (2011) Forests and climate change adaptation strategies in Cameroon. Mitig Adapt Strateg Glob Change 16:369–385 Bennett EL, Robinson JG (2000) Hunting of wildlife in tropical forests: implications for biodiversity and forest peoples, vol 76, World Bank biodiversity series. World Bank, Washington, DC Brown LR (2012) Full planet, empty plates: the new geopolitics of food scarcity. WW Norton and Company, New York De Beer JH, McDermott M (1989) The economic value of non-timber forest products in South East Asia. The Netherlands Committee for IUCN, Amsterdam Fentahun MT, Hager H (2009) Exploiting locally available resources for food and nutritional enhancement: wild fruits diversity, potential and state of exploitation in the Amhara region of Ethiopia. Food Security 1:207–219 Fa J, Currie D, Meeuwig J (2003) Bushmeat and food security in the Congo Basin: linkages between wildlife and people’s future. Environ Conserv 30:71–78 Grosskinsky B (2000) Nutritional contribution of IWFP. In: Grosskinsky B, Gullick C (eds) Exploring the potential of indigenous wild food plants in southern Sudan. Proceedings of a workshop held in Lokichoggio, Kenya. USAID, Nairobi Guinand Y, Lemessa D (2001) Wild food plants in Ethiopia: reflections on the role of “wild foods” and “famine foods” in times of drought. United Nations Development Program (UNDP), Emergencies Unit for Ethiopia (UNDP-EUE), Rome

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Heubes J, Heubach K, Schmidt M, Wittig R, Zizka G, Nuppenau E, Hahn K (2012) Impact of future climate and land-use change on non-timber forest product provision in Benin, West Africa: linking niche-based modelling with ecosystem service values. Econ Bot 66(4):383–397 Jumbe CBL, Bwalya SM, Husselman M (2008) Contribution of dry forests to livelihoods and the national economy in Zambia. Centre for International Forestry Research (CIFOR), Lusaka, p 28 Kalame FB, Kudejira D, Nkem J (2011) Assessing the process and options for implementing National Adaptation Programmes of Action (NAPA): a case from Burkina Faso. Mitig Adapt Strateg Glob Change 16:535–553 McGarry D, Shackleton CM (2009) Children navigating rural poverty: rural children’s use of wild resources to counteract food insecurity in the Eastern Cape, South Africa. J Child Poverty 15(1):19–37 McSweeney K (2005) Natural insurance, forest access and compound misfortune: forest resources in small holder coping strategies before and after Hurricane Mitch, Northeastern Honduras. World Dev 33:1453–1471 Mitho¨fer D, Waibel H (2004) Seasonal vulnerability to poverty and indigenous fruit use in Zimbabwe. Rural poverty reduction through research for development and transformation conference, Deutscher Tropentag, University of Hannover, Berlin Mojeremane W, Tshwenyane SO (2004) Azanza garckeana: a valuable indigenous fruit tree of Botswana. Pak J Nutr 3(5):264–267 Nkem J, Kalame FB, Idinoba M, Somorin OA, Ndoye O, Awono A (2010) Shaping forest safety nets with markets: adaptation to climate change under changing roles of tropical forests in Congo basin. Environ Sci Policy 13:498–508 Oluoch MO, Germain PN, Drissa S, Abukutsa-Onyango MO, Diouf M, Shackleton CM (2009) Production and harvesting systems for African indigenous vegetables. In: Shackleton CM, Pasquini MW, Drescher AW (eds) African indigenous vegetables in urban agriculture. Earthscan, London, pp 145–170 Osbahr H, Twyman C, Adger N, Thomas D (2008) Effective livelihood adaptation to climate change disturbance: scale dimensions of practice in Mozambique. Geoforum 39:1951–1964 Shackleton CM, Shackleton SE, Gambiza J, Nel E, Rowntree K, Urquhart P, Fabricus C, Ainslie A (2010) Livelihoods and vulnerability in the arid and semi-arid lands of southern Africa: exploring the links between ecosystem services and poverty alleviation. Nova Publishers, New York, p 267 Shackleton SE, De Lang, Angelsen A (2011) From subsistence, to safety nets and cash income: exploring the diverse values of non-timber forest products for livelihoods and poverty alleviation. Chapter 3 – pp 55–82. In: Shackleton SE, Shackleton CM, Shanley P (eds) Non-timber forest products in the global context. Springer, Heidelberg. ISBN 978-3-642-1798-2; e-ISBN 978-3-642-17983-9, 280 pp Shackleton S, Shackleton C (2011) Exploring the role of wild natural resources in poverty alleviation with an emphasis on South Africa. In: Hebinck P, Shackleton C (eds) Reforming land and resource use in South Africa: impact on livelihoods. Routledge, Canada, pp 209–234 Shackleton SE, Shackleton CM (2012) Linking poverty, HIV/AIDS and climate change to human and ecosystem vulnerability in southern Africa: consequences for livelihoods and sustainable ecosystem management. Int J Sust Dev World 19(3):275–286 Takasaki Y (2011) Do the commons help augment mutual insurance among the poor? World Dev 39(3):429–438 Vo¨lker M, Waibel H (2010) Do rural households extract more forest products in times of crisis? Evidence from the mountainous uplands of Vietnam. Forest Policy Econ 12:407–414

Impacts of Climate Change on Food Availability: Distribution and Exchange of Food

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Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Food Prices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Infrastructures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Food Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Food Exchange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Food Provision Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Keywords

Infrastructures • Food storage • Food exchange • Food prices • Food aid

Definition Food availability is determined by the physical quantities of food that are produced (previous section), stored, processed, distributed, and exchanged. In fact, most food is not produced by individual households, but acquired through buying, trading, and borrowing (Du Toit and Ziervogel 2004). Food distribution refers to how food is made available (physically moved), in what form, when, and to whom; food exchange refers to how much of the available food is obtained through exchange

M.G. Rivera Ferre Polytechnic School, Environment and Food Department Research Group incl. Societies, Policies and Communities (SoPCi), University of Vic – Central University of Catalonia, Vic, Spain e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_119, # Springer Science+Business Media Dordrecht 2014

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mechanisms such as barter, trade, purchase, or loans (Ingram 2011). That is, the food availability element does not only depend on food production, and other social and economical factors need also to be considered. For instance, distribution networks (e.g., roads, communication, modes of transport, and information systems) and the financial situation of governments and consumers determine the ability to get imports/movements inside a deficit country and/or area. The storage and handling capacity is important for physical food reserves. Also, high market prices for food are usually a reflection of inadequate availability. Growing scarcities of water, land, and fuel are likely to put increasing pressure on food prices, even without climate change. Policies related to climate change, such as mitigation practices that create land-use competition and the attribution of market value to environmental services to mitigate climate change, have the potential to cause changes in relative prices for different food items, and therefore increase in price volatility (FAO 2008). A new and interesting view about food availability, yet receiving little attention, introduces the concept of energy efficiency. Food energy efficiency is our ability to minimize the loss of energy in food from harvest potential through processing to actual consumption and recycling (Nellemann et al. 2009). By optimizing this chain, food supply and thus availability can increase. Only an estimated 43 % of the cereal produced is available for human consumption, as a result of harvest and postharvest distribution losses and use of cereal for animal feed. Furthermore, the 30 million tonnes of fish needed to sustain the growth in aquaculture correspond to the amount of fish discarded at sea today (Nellemann et al. 2009). The scale is an important factor that needs to be considered when addressing the availability component of food security. All food is transported from producer to consumer, but the transport distance, the transport mode, and the number of transportation steps (i.e., the distribution of food) are often very different, and thus, large differences in food distribution do exist. There are two main types of food chains: local and global, which are differently impacted by global environmental change. Food produced and sold locally is likely to involve only one or two distribution steps from producer to consumer, involving a small transport distance, e.g., typically less than 50 km (Watkiss 2009). Other food is imported from many thousands of kilometers away. Although most food trade takes place within national borders (FAO 2008) and approximately only one sixth of food produced is distributed or consumed internationally, it is estimated that future land and water constraints, under current food policies, can increase the number of people relying on imported food (Fader et al. 2013). The move to wider food sourcing is strongly linked to the increasing dominance of retailers in developing global supply chains. The scale of policies is also important. For instance, the ability of groups to secure food, resources, and livelihoods at the local scale is at least partially determined by national processes (Ziervogel and Frayne 2011). National governments have various policy instruments available to assist populations to be food secure, including distributing food aid, controlling domestic prices, implementing safety nets, and promoting active local, national, and regional market participation

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(Ziervogel and Ericksen 2010). Thus, in policy terms it is necessary to tackle food insecurity at all the local, provincial, and national scales. In sum, while the components of food availability are contextual, the major elements of a secure food supply include domestic production, reliable import capacity, presence of food stocks, availability of social protection measures (e.g., food provision and food safety nets), decent transportation infrastructure, and, when necessary, access to food aid (Ziervogel and Ericksen 2010). These components are also interconnected, for instance, food storage depends on the good quality of infrastructures, and vice versa. Furthermore, the different requirements of different food chains need to be considered when addressing food availability, including differences among local and global networks, differentiation between cities and rural areas, the different needs of infrastructures, or the so-called distribution transition (e-shopping, food waste). Here, due to space constraints, I will address the most analyzed impacts of global environmental change on food distribution and exchange and some key adaptation strategies. Poor infrastructures, high transportation costs, high food costs, community remoteness, increasing dependency on imported foods, lack of economic opportunities and employment, the increasing challenges and costs of wildlife harvesting in some areas, these factors, and others contribute to increasing concerns over the level of food security in many places, reflecting the inability to consume food for many people.

Food Prices High market prices for food are usually a reflection of inadequate availability. A change in climate or climate extremes may impact on the availability of certain food products which will impact on their price. High prices may make certain foods unaffordable and can in turn influence individual nutrition and health (FAO 2008). Changes in food seasonality attributed to climate change can lead to certain food products being scarcer at certain times of the year (Ziervogel and Frayne 2011). The vast majority of poor urban and rural households are hit hardest by higher prices. Among the poor, it is the landless and female-headed households that are most vulnerable to sharp rises in basic food prices. Although most of the production is in rural areas, the impacts of scarcity are felt acutely by the increase in price that filters through to urban consumers (Ziervogel and Frayne 2011). Most frequently, food needs to be purchased in urban areas and often in rural areas as well. According to UN estimates, almost all of the world’s population growth between 2000 and 2030 will be concentrated in urban areas in developing countries. Large urban markets create the scope for the establishment of big supermarket chains, with implications for the entire food supply chain. In a business-as-usual scenario, this growth in urban demand will most likely be satisfied not from small family farms, but rather from distant large commercialized production systems in breadbasket regions through long food supply chains (HLPE 2012). Moreover, markets are predicted to become more concentrated with urbanization and the trend in dietary shifts towards more processed food and

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a higher share of animal protein exacerbated. The nutrition transition leads to a disparity between what can be and is locally grown and what is locally consumed, posing the challenge to decision-makers whether consumer preferences or basic needs need to be addressed (Arntzen et al. 2004). Global food chains are more prone to price volatility than local food chains in the absence of regulation policies. Also relevant here are the poor connections between urban and rural areas which hinder price transmissions towards local markets, broadening the gap between urban demand and rural production against local food chains. Cost of food is higher in distanced communities (FAO 2008). Different factors favor the high cost of food here, including high costs of fuel and equipment to practice subsistence economies, due to remote location and high fuel prices in general. Here climate change exacerbates problems because in many cases it is necessary to travel further in order to obtain sufficient food. Another factor is related to low incomes and limited job opportunities; if climate variability impacts on job opportunities, such as reduced seasonal work during droughts, it can also impact on the ability to purchase food, resulting in insufficient resources to purchase store-bought food. At the national and global scales, policies related to food liberalization, government controls over prices, and market systems affect food prices (Nellemann et al. 2009). For instance, price regulation and government subsidies are crucial safety nets and investments in production, all needed to favor food security (HLPE 2012).

Infrastructures In cities the majority of food needs to be transported in from rural areas. Allocation of food to different areas can therefore impact its availability and hence accessibility (Ziervogel and Frayne 2011). For instance, in Germany (also UK), the amount of food consumed has not grown much in the last three decades, but food transport (in tonne-km per capita) has almost doubled, due to customer preferences for food from other countries, transport policies (cheap air and boat transport), the location and production patterns of the food industry, and retailers (Watkiss 2009) in an enabling policy environment. Damage to infrastructure is expected to increase, as the infrastructures are not generally built to deal with more frequent and severe floods and extreme temperatures. When damage is not repaired, the resulting impacts on food distribution become substantial and lasting. Where infrastructure is affected by climate, through either heat stress on roads or increased frequency of flood events, there are impacts on food distribution (FAO 2008), with negative consequences for food security in poor urban and rural households and communities (Ziervogel and Frayne 2011). Also relevant is the impact of climate change on fisheries that can result in a change of location of marine fisheries so that catches are landed in different ports. Ports will also be specially damaged by flooding and extreme events, affecting both fisheries as well as food trade. Climate change poses some particular civil engineering challenges to

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infrastructure provision. Here the strategy deals with infrastructure from a climate change perspective on a sector by sector basis and includes buildings, energy, lighting, ports, renewables, transport, waste, and water.

Food Storage Food availability depends on the reliability of import capacity, the presence of food stocks and – when necessary – access to food aid (FAO 2008). These factors in turn often depend on the ability to store food. Storage is affected by strategies at the national level and by physical infrastructure at the local level. The logistics of transporting and storing food can be affected by climate change, for example, increasing the need for refrigeration or postharvest drying. Also, food storage requirement conditions can change as a result of shorter shelf life of perishable products. Food storage at local level needs to consider the capacity of small-scale farmers to keep food in their farms or other collective infrastructures, as well as in the cities. Storage at this level in a climate change context is also important if distribution infrastructures are predicted to fail. At the national level countries normally prepare themselves for potential shortages of strategic staple grain reserve based on seasonal projections; at the global level, it is necessary to set up an internationally governed set of physical and virtual food reserves to support food availability (and affordability).

Food Exchange Exchange of food takes place at all levels – individual, household, community, regional, national, and global. At the lowest levels, exchanges usually take the form of reciprocal hospitality, gift giving or barter, and serve as an important mechanism for coping with supply fluctuations. If changing climatic conditions bring about trend declines in local production, the capacity of affected households to engage in these traditional forms of exchange is likely to decline (FAO 2008). At the regional, national, and global level, trade remains the main mechanism for exchange.

Food Provision Systems Food aid is expected to increase due to the growing gap in agricultural production potential between surplus and deficit areas. Where countries or consumers cannot afford to purchase food, food aid will grow and becomes more frequent. This trend is already discernable at the local and national level. Food provision systems rely on production systems, distribution and storage systems, distribution and communication networks, and system’s governing economic access to food. Within this the adequacy and reliability of food provision depends on

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the performance of each subsystem and the interactions between them. For example, a lower than anticipated harvest could be compensated by rapid increase in food imports, but this requires a good distribution network (Arntzen et al. 2004). Some programs exist in different countries to buffer the impact of climate change on food distribution and exchange. These include infrastructure-building programs that usually require participants to do physical work for building and maintaining rural infrastructure being exchanged for food, training, education, or other inputs. Relief-programs also exist, which are designed as a mechanism for mitigating the consequences of disasters like floods, cyclones, and other natural calamities (Ahmed et al. 2009). Drought relief and aid programs remain a critical component of food provision despite its short-term nature and the risk of consumer dependency on food aid. Safety nets, such as food or cash-based transfers, are intended to protect households from experiencing food insecurity in situations of price volatility, chronic poverty, or repeated production failures. They have become popular with donors and food security analysts as they are less market distorting than price controls, and they ideally can be targeted at the most vulnerable or poorest households (Ziervogel and Ericksen 2010). Food provision systems again are interconnected with other elements, such as food storage to provide emergency relief during periods of natural disaster or national policies to stabilize the market price of food. The form of food transfer also has an effect on who benefits within the household. In Bangladesh, the food interventions that provide rice have a larger effect on men’s caloric intake relative to women’s, whereas the converse is true for the one intervention that provides atta whole-wheat flour. Here, the use of a less-preferred food increases the share of the food that goes to women relative to men (Ahmed et al. 2009).

Conclusions Food availability depends not only on production, but also on other factors such as distribution, storage, and exchange of food. These factors are poorly considered, but their importance will increase in a context of global environmental (and social) changes. All these elements take place at different scales, from local to global. Also, global and local food chains exist which are impacted differently by global changes. Specific and contextual policies are required to tackle food availability problems at all these levels.

References Ahmed AU, Quisumbing AR, Nasreen M, Hoddinott JF, Bryan E (2009) Comparing food and cash transfers to the ultra poor in Bangladesh. Research monograph 163. IFPRI, Washington, DC Arntzen J, Muchero M, Dube P (2004) Global environmental change and food provision in Southern Africa. Report on GECAFS in southern Africa. http://www.oceandocs.net/ bitstream/1834/691/1/GECAFS%20Southern%20Africa%20Report.pdf

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Du Toit A, Ziervogel G (2004) Vulnerability and food insecurity: background concepts for informing the development of a national FIVIMS for South Africa. http://www.agis.agric.za/ agisweb/FIVIMS_ZA.html Fader M, Gerten D, Krause M, Lucht W, Cramer W (2013) Spatial decoupling of agricultural production and consumption: quantifying dependences of countries on food imports due to domestic land and water constraints. Environ Res Lett 8(1) (marzo 1): 014046. doi:10.1088/ 1748-9326/8/1/014046 FAO (2008) Climate change and food security: a framework document. FAO Interdepartmental Working Group on Climate Change, Rome HLPE (2012) Food security and climate change. The High Level Panel of Experts on Food Security and Nutrition. CFS, Rome Ingram J (2011) A food systems approach to researching food security and its interactions with global environmental change. Food Secur 3(4):417–431. doi:10.1007/s12571-011-0149-9 Nellemann C, MacDevette M, Manders T, Eickhout B, Svihus B, Prins AG, Kaltenborn BP (2009) The environmental food crisis – The environment’s role in averting future food crises. A UNEP rapid response assessment. United Nations Environment Programme, GRID-Arendal, Arendal Watkiss P (2009) European food systems in a changing world. ESOF/COST Forward Look. Strasbourg: ESOF/COST. http://www.esf.org/activities/forward-looks/life-earth-andenvironmental-sciences-lesc/current-forward-looks-in-life-earth-and-environmental-sciences/ european-food-systems-in-a-changing-world.html Ziervogel G, Ericksen PJ (2010) Adapting to climate change to sustain food security. Wiley Interdiscip Rev Clim Change 1(4):525–540. doi:10.1002/wcc.56 Ziervogel G, Frayne B (2011) Climate change and food security in Southern African cities. Urban food security series 8. Queen’s University and AFSUN, Kingston and Cape Town

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Contents Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Access and Entitlements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Changes in Agricultural Production Affecting Food Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Climate Change Impacts on Livelihoods and Food Accessibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Climate Change Impacts on Access to Food Amongst Marginalized Populations . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Keywords

Access • Entitlements • Vulnerability • Resilience

Definitions Food insecurity refers to a situation that exists when people lack secure access to sufficient amounts of safe and nutritious food for normal growth and development and an active and healthy life. It may be caused by the unavailability of food, insufficient purchasing power, inappropriate distribution, or inadequate use of food at the household level. Food insecurity, poor conditions of health and sanitation, and inappropriate care and feeding practices are the major causes of poor nutritional status. Food insecurity may be chronic, seasonal, or transitory (FAO et al. 2012). Food accessibility refers to food affordability, allocation, and preferences that enable people to effectively translate their hunger into demand. It is a measure of

C. Sage Department of Geography, University College Cork, Cork, Ireland e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_120, # Springer Science+Business Media Dordrecht 2014

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the ability to secure entitlements, which are defined as the set of resources (including legal, political, economic, and social) that an individual requires to obtain access to food. Poverty and vulnerability play a central role in food accessibility, as this component is centrally concerned with the purchasing power of households and individuals and the social dynamics governing access to food (Ziervogel and Frayne 2011).

Introduction The standard definition of food security that originated in the 1996 World Food Summit Plan of Action has proven remarkably durable and is of interest to us for the pivotal role given to the notion of access to food. Yet definitional ease has not made the resolution of the problem any closer, and indeed 870 m people are still chronically undernourished (FAO et al. 2012). Indeed, events since 2007, when the numbers of hungry began to climb steeply in line with rising food prices and as part of a nexus of interrelated processes, have demonstrated that food insecurity remains a deeply intractable problem (Sage 2013) and one likely to be significantly exacerbated by climate change effects. While much of the scientific discussion around food security is framed by the imperative of producing more food – from 50 % to100 % more by 2050 according to different sources – such aspirations do not guarantee future food security. First, the mere presence of an adequate supply does not ensure that a person can obtain and consume food: that person must first have access to the food through his/her entitlements (see below). The enjoyment of entitlements that determine people’s access to food depends on allocation mechanisms, affordability, and cultural and personal preferences for particular food products. Increased risk exposure resulting from climate change will reduce people’s access to entitlements and undermine their food security (FAO 2008). Secondly, this preoccupation with feeding a projected population of nine billion by mid-century – a one-third increase on today’s population – overlooks the matter that up to half of global food currently produced does not reach a human stomach (IMechE 2012) but is lost or wasted between the field and the plate. Third, around one-third of global grain production and the same proportion of arable land is currently accounted for by the production of livestock feeds which could otherwise feed people directly (Sage 2012). And fourth, the rush to biofuels as a way of enhancing energy security has had huge repercussions on food prices, and it has been estimated that the volume of maize (corn) currently diverted to ethanol distillation in the United States would be sufficient to feed at least 400 million people for 1 year. Consequently, given that warming of the climate system is now unequivocal and that climate change is expected to pose major challenges for agricultural production, it is vital to better understand how this will shape access to food around the world. As climate change will likely have sharper and more immediate consequences on food access in poorer countries of the Global South, it is here that the article is focused.

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Access and Entitlements Whereas earlier definitions had placed emphasis upon the availability of food at all times, it was the work of an Indian economist Amartya Sen that did much to shift thinking around the causes of hunger. In his seminal work Poverty and Famines, Sen (1981) demonstrates that hunger and starvation are not conditions that inevitably arise as a consequence of a decline in food availability. Rather, they reflect the circumstances of people not being able to secure access to food. This can be explained, argues Sen, by understanding people’s entitlement relations. On the basis of their initial endowments in land, other assets, and labor power, a person has entitlements to his/her own production, the sale of labor power for wages, or the exchange of products for other goods (e.g., food). Under “normal” conditions these entitlements provide the basis for survival; however, emerging circumstances – such as the possible effects of climate change – may unfavorably impact upon them. Thus, a drought-induced collapse of the local labor market severely impacts upon those whose main entitlement to food is drawn from the sale of their labor. Moreover, a rise in grain prices affects all those who purchase their food needs and who may simultaneously experience a collapse in the production or the price of their own commodities. An understanding of entitlements has become a vital part of a social vulnerability approach which recognizes the differential impacts of environmental, economic, and other risks upon individuals, households, communities, and regions. This approach breaks with past preoccupation with the arithmetic of food supply and human numbers in order to identify those who are most vulnerable to food insecurity and to better understand the basis of their survival strategies; that is, their ability to cope with various forms of uncertainty whether chronic or on seasonal, periodic, or irregular time scales. Moreover, recognizing the influence of external factors (such as climatic or economic shocks) on local food-provisioning systems reveals the nested interconnections that link the food security of individuals and households to the global level (Maxwell and Slater 2003).

Changes in Agricultural Production Affecting Food Access Regional scenario-building exercises using general circulation and statistical crop models point to a growing divergence between high and low latitudes in terms of agricultural output. Within the tropics there is particular concern for the effects of higher temperatures, with resulting heat stress on crops, animals, and farmers; changing precipitation patterns, disrupting established cycles of rain-fed farming, and associated livelihood activities; rising sea levels that will not only cause inundation of coastal farmland but trigger saline intrusions of freshwater aquifers; and increased likelihood of extreme weather events, such as drought and floods that will not only directly impact agricultural production but destroy physical infrastructure affecting food storage and distribution. While any one of these aspects of climate change exert greater stress on food-provisioning arrangements at local and regional

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level, it is anticipated that in practice there are likely to be dynamic interactions between these different variables creating greater turbulence and food price volatility on global markets (World Bank 2012). For example, changes in temperature and in the amount, timing, and intensity of rainfall can result in reduced yields and lower overall levels of food production. This leaves households with inadequate amounts to sustain their consumption needs until the next harvest and/or sell into local and regional markets. This decline invariably exacerbates price fluctuations which are likely to be transmitted into national urban food markets. Here access to food will be determined by the ability to pay higher prices and, depending on how these price rises occur alongside changes in income, can make existing food secure populations vulnerable to food insecurity in the future. In urban areas, food availability is seldom the major constraint, but rather it is lack of access to food for the urban poor, especially children. In some places urban agriculture provides some produce, although this too could be impacted by climate change through stress on urban water resources. Access to food in urban areas is also likely to be impacted by climate change because most food is purchased in urban areas. Food prices are a direct determinant of affordability and hence access. Food distribution systems in cities also play a role in food accessibility (Ziervogel and Frayne 2011). It may be possible to make agricultural systems more resilient to climate change effects by changing farming practices, for example, from staggering planting dates to practicing water conservation methods such as using mulches or rainwaterharvesting techniques. The introduction of more heat- or drought-tolerant varieties of existing crops, or replacing those with new crop species, may also be an option but may have profound implications for household labor and other resources. With respect to livestock there is evidence to suggest that camels may be replacing cattle in dryland areas of East Africa given their greater capability to withstand drought conditions as well as their capacity to produce more milk over a longer lactation period. Certainly with the evidence demonstrating that amongst resource poor low-income households, agriculture has a significant bearing on poverty reduction and therefore in reducing hunger and malnutrition, every effort must be made to make farming systems in vulnerable regions more resilient to the effects of climate change. Meanwhile, from an urban management perspective, supporting local food production in cities is important in promoting livelihoods and health, reducing costly food imports, using local waste productively, and contributing to sustainable livelihoods (Ziervogel and Frayne 2011).

Climate Change Impacts on Livelihoods and Food Accessibility A livelihood comprises the capabilities, assets (stores, resources, claims and access) and activities required for a means of living; a livelihood is sustainable which can cope with and recover from stress and shocks, maintain or enhance its capabilities and assets, and provide sustainable livelihood opportunities for the next generation. (Chambers and Conway 1992, pp. 7–8).

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While at its simplest notion of livelihoods represents a means of securing a living, its elements and structure can be complex as households and individuals mobilize their capabilities and assets to obtain food, employment, and income. The great majority of the world’s most food insecure live in rural areas of the poorest countries, and consequently, their livelihoods are almost entirely dependent upon agriculture, as small holder farmers, landless wage workers, or pastoralists. It is this group of small-scale farmers and landless laborers, with limited resources, who are particularly susceptible to the economic effects of climate change (HLPE 2012). Protracted crises, where climate change may place greater pressure on resources (grazing land, water, firewood), can result in heightened insecurity that then results in severe disruption of livelihood activities. Initially the using up of stores is gradually replaced by the depletion of assets (such as jewelry, tools, utensils, animals, even land) as these are converted into food for survival. One long-established livelihood strategy in rural areas has been periodic, seasonal, or long-term migration to urban centers or other sites of employment in search of wage-earning opportunities. Whereas much mobility within and across national boundaries has hitherto been largely driven by socioeconomic factors, it is now recognized that environmental factors will increasingly influence migration. However, while environmental change can increase the incentive to move, it can also limit the capacity to do so (Black et al. 2011). Moreover, people are as likely to migrate into places of environmental vulnerability as away from them. For example, in dryland areas, where rainfall variability is a significant contributor to poverty and food insecurity and where mobility is a long-established livelihood strategy, analysis of long-term global data sets demonstrates high rates of net out-migration (de Sherbinin et al. 2012). However, the same work reveals high rates of net inward migration into coastal zones including flood-prone and cyclone-affected areas. As people move toward major urban conurbations in search of employment, their exposure to climate hazards is not necessarily alleviated. For example, in Dakar, Senegal, 40 % of migrants who moved there between 1998 and 2008 live in areas of high flood risk. In many countries – Bangladesh, Nigeria, Egypt, Vietnam, amongst them – very densely populated coastal regions are continuing to attract inward migration but are highly vulnerable to storm surges and sea-level rise.

Climate Change Impacts on Access to Food Amongst Marginalized Populations Climate change can deepen the fault lines of existing inequalities that operate along multiple social axes, principally of gender, age, marital status, ethnicity, and ascribed status within the prevailing society (e.g., caste). This has implications for entitlement relations and access to food, as outlined above, and consequently for nutritional security. Even within the household under normal conditions, it has been well documented that the allocation of food frequently favors males over females. Tightening stocks may disproportionately affect women and girls who eat what

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remains in the pot after the men have fed. Yet the work performed by women and girls may increase as a consequence of climate warming and drying. The gender roles of water and fuel collection may make journeys longer and leave women little time to pursue income-generating activities. Furthermore, in developing countries as a whole, women constitute approximately 43 % of the agricultural labor force yet are typically disadvantaged in terms of access to inputs (water, fertilizers, and seeds) and credit and lack titles to land. This affects farm productivity and leaves female-headed households more vulnerable to food insecurity. Women farmers are generally more likely to produce a greater variety of foods for household consumption than men who are more locked into extension services encouraging commodity production. Small-scale production of fruits and vegetables by women has a greater chance of maintaining nutritional security. Marginalization is a complex social, economic, and political process which takes many different forms in different societies. However, it is not difficult to imagine scenarios where climate change serves to exacerbate and deepen marginalization and enflame hostilities as groups struggle to retain their existing rights and access to resources. It has been argued, for example, that climate change will worsen instability in already volatile regions. Burke et al. (2009) use regression analysis of climate variation and conflict events in Africa to demonstrate that increases in temperature are strongly related to conflict incident. Others, however, argue for a more nuanced understanding of the ways that climate parameters (temperature, but also precipitation) may trigger or alleviate conflict (O’Loughlin et al. 2012). Another way in which marginalization may occur is through powerful storm events that damage transport infrastructure, causing landslides or flooding of roads and rail lines, destroying bridges, and so on, and restricting the capacity of moving food supplies from food surplus to food-deficit regions. Stored food can also be lost at village and household level from increased pest and fungal damage to regional warehouses suffering power outages affecting bulk reserves. Under such circumstances rising prices for food may exacerbate political tensions and widen social divisions.

Conclusion While addressing vulnerability to climate change requires urgent attention, it must be remembered that this is another confounding variable alongside existing determinants of food insecurity. Improving access to food will not automatically result from increased agri-commodity production especially under the prevailing model of highly mechanized, large-scale, high-input farming that dominates throughout the developed world and is being promoted as the solution for the South. This model currently produces enough food to feed the world, yet almost one billion are hungry. Such technologies do not enhance the human right to adequate food (De Schutter 2011).

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Rather, improving access to food under climate change will require public investment in strategies for community-based adaptation. This will include on-farm experimentation utilizing locally developed seeds and knowledge; better water management practices involving rainwater harvesting, storage, and use; soil moisture conservation; and other techniques. Yet building local resilience to climate change must be accompanied by institutional efforts at multiple scales in order to ensure individual, household, and community entitlements are secured in order to improve access to food.

References Black R, Bennett S, Thomas S, Beddington J (2011) Migration as adaptation. Nature 478:447–449 Burke MB, Miguel E, Satyanath S, Dykema JA, Lobell DB (2009) Warming increases the risk of civil war in Africa. Proc Natl Acad Sci USA 106:20670–20674 Chambers R, Conway G (1992) Sustainable rural livelihoods: practical concepts for the 21st century. Discussion paper 296, Institute of Development Studies, University of Sussex De Schutter O (2011) The right of everyone to enjoy the benefits of scientific progress and the right to food: from conflict to complementarity. Hum Right Q 33:304–350 de Sherbinin A, Levy M, Adamo S, MacManus K, Yetman G, Mara V, Razafindrazay L, Goodrich B, Srebotnjak T, Aichele C, Pistolesi L (2012) Migration and risk: net migration in marginal ecosystems and hazardous areas. Environ Res Lett 7. Open access: http://dx.doi.org/ 10.1088/1748-9326/7/4/045602 FAO (2008) The state of food insecurity in the world 2008: High food prices and food security threats and opportunities. Food and Agriculture Organization of the United Nations, Rome. FAO, WFP, IFAD (2012) The state of food insecurity in the world 2012. Economic growth is necessary but not sufficient to accelerate reduction of hunger and malnutrition. FAO, Rome High Level Panel of Experts on Food Security and Nutrition (HLPE) (2012) Food security and climate change. A report by the High Level Panel of Experts on Food Security and Nutrition of the Committee on World Food Security, Rome Institution of Mechanical Engineers (IMechE) (2012) Global food: waste not, want not. IMechE, London, www.imeche.org Maxwell S, Slater R (2003) Food policy old and new. Dev Policy Rev 21(5–6):531–553 O’Loughlin J, Witmer F, Linke A, Laing A, Gettelman A, Dudhia J (2012) Climate variability and conflict risk in East Africa, 1990–2009. Proc Natl Acad Sci USA 109(45):18344–18349 Sage C (2012) Environment and food. Routledge, Abingdon Sage C (2013) The inter-connected challenges for food security from a food regimes perspective: energy, climate and malconsumption. J Rural Stud 29(1):71–80 Sen A (1981) Poverty and famines: an essay in entitlement and deprivation. Clarendon, Oxford The World Bank (2012) Turn down the heat: why a 4 C warmer world must be avoided. A report for the World Bank by the Potsdam Institute for Climate Impact Research and Climate Analytics. The World Bank, Washington, DC Ziervogel G, Frayne B (2011) Climate Change and Food Security in Southern African Cities. 8, Urban Food Security Series. Queen’s University and AFSUN, Kingston/Cape Town

Impacts of Climate Change on Food Utilization

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Noora-Lisa Aberman and Cristina Tirado

Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Health, Water, and Food Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agricultural Production and Dietary Intake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

Climate change, one of the worlds most critical current and future challenges, is increasingly impacting food security, especially for the world’s poor and vulnerable. Food utilization, one of the four dimensions of food security, pertains to the biological processing of food by individuals and is typically measured with nutritional indicators. The pathways through which climate change impacts food utilization can be summarized as diet and health. Current literature on these pathways is discussed, highlighting the need for a systems approach to food security that goes beyond promoting agricultural productivity and encompasses issues related to health and vulnerability, especially of women.

Some of the content in this chapter was adapted from a previous publication: Brian Thompson and Marc J. Cohen, eds., The Impact of Climate Change and Bioenergy on Nutrition, Dordrecht: Springer and Rome: FAO, 2012. N.-L. Aberman (*) International Food Policy Research Institute, Washington, DC, USA e-mail: [email protected] C. Tirado PAHO/WHO, Rio de Janeiro, Brazil UCLA School of Public Health e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_124, # Springer Science+Business Media Dordrecht 2014

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Keywords

Climate change • Food security • Food utilization • Nutrition • Health • Gender • Vulnerability

Introduction Climate change will impact food security, particularly for the world’s poor rural populations, through a variety of pathways. For the 75 % of the world’s poor who live in rural areas and derive their primary livelihoods from agriculture (World Bank 2008), increasing climatic shocks and variability could prove to be one of the most critical current and future challenges faced by the developing world. According to the IPCC, climate variability and change will lead to more intense and longer droughts, particularly in the tropics and subtropics (Trenberth et al. 2007). In addition, the frequency of heavy precipitation events has increased over most land areas. It is also very likely that heat waves and heavy precipitation events will become more frequent and that future tropical cyclones will become more intense (Meehl et al. 2007; Trenberth et al. 2007). Food utilization, one of the four dimensions of food security, is conceptualized in many different ways. Some definitions of food utilization encompass the household’s treatment of the food as well as the biological processes of food utilization, and others narrow the definition to pertain only to an individual’s biological capacity to make use of food for a productive life (Swindale and Bilinsky 2006). The Food and Agriculture Organization (FAO) describes food utilization as simply “the way in which the body makes the most of various nutrients in the food” (2008). The World Food Programme (WFP) takes a slightly broader view of utilization, including the “households’ use of the food to which they have access [as well as the] . . .individuals’ ability to absorb and metabolize the nutrients” (2009). Here we emphasize the narrower view of food utilization as pertaining only to the individual’s biological processing of the food consumed. Food utilization is typically measured with indicators of nutritional status (Ecker and Breisinger 2012; Swindale and Bilinsky 2006). Utilization can be considered the final step toward reaching adequate nutritional status. As depicted in Fig. 83.1,

Stability

Availability of food

Access to food

Utilization of food

Fig. 83.1 Food security and nutrition (Adapted from Weinga¨rtner 2005)

Nutritional Status

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Climate Change (warming, droughts, floods)

Health

Agricultural production (including fishing, livestock and other rural livelihoods)

(Food safety, water quality and sanitation) Women’s time / Care and feeding practices

Vulnerability

Dietary intake (dietary diversity and diet quality)

Gender norms Diarrheal diseases

Vector-borne diseases and zoonosis

Nutritional absorption and requirements

Food Utilization

Nutritional status

Fig. 83.2 Framework for climate change and food utilization (Source: Authors)

with stable availability of and access to food, proper utilization of food then leads to adequate nutrition. Lobell and Burke (2010) describe two key pathways through which climate change impacts food utilization, which we summarize as diet and health. Diet pathways entail impacts on the nutrient content of the food people grow and eat. Health pathways entail food and water safety and diseases and infections that impact the ability of the body to absorb nutrients as well as nutrient requirements. Furthermore, vulnerability and gender norms are aspects of the underlying context that impact behaviors and coping strategies for climate change. Also, health and diet themselves interact as undernutrition increases susceptibility to disease, which may decrease productivity and lead to more food insecurity and undernutrition. The details of these pathways are visualized in Fig. 83.2.

Health, Water, and Food Safety By 2020, between 75 million and 250 million people in Africa are projected to be exposed to increased water scarcity. If coupled with increased demand, this will adversely affect livelihoods and exacerbate water-related problems (Boko et al. 2007; Kundzewicz et al. 2007). Furthermore, the risk of flooding of human

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settlements may increase, from both sea-level rise and increased heavy precipitation in coastal areas. This is likely to result in an increase in the number of people exposed to diarrheal and other infectious diseases, thus lowering their capacity to utilize food effectively. Most of the projected climate-related disease burden will result from increases in diarrheal diseases and malnutrition. Diarrheal diseases particularly affect nutrient absorption. Associations between monthly temperature and diarrheal episodes and between extreme rainfall events and monthly reports of outbreaks of water-borne disease have been reported worldwide (Confalonieri et al. 2007). Higher temperatures have been associated with increased episodes of diarrheal disease in adults and children in Peru, where diarrheal reports increased 8 % for each degree of temperature increase (Checkley et al. 2000). Furthermore, there is some evidence that climate change will impact food safety due to changes in ambient temperature, salinity, and pH on the survival, multiplication, and distribution of microorganisms (Tirado and Meerman 2012). Diarrheal food-borne diseases such as salmonellosis have been found to increase by 12 % for each degree increase in weekly or monthly temperature above 6
C ambient temperature (Kovats et al. 2004). Increased ocean temperatures are leading to increased densities of Vibrio spp. (diarrheal agent) in shellfish (Zimmerman et al. 2007). Rising temperatures have also been found to increase naturally occurring biotoxins found in many crops that can contaminate staple foods eaten by people and meat and milk of animals that are fed these crops, causing food-borne diseases that further exacerbate malnutrition and food insecurity (Tirado and Meerman 2012). Overall, climate change is projected to increase the burden of diarrheal diseases in low-income regions by approximately 2–5 % in 2020 and will impact low-income populations already experiencing a large burden of disease (CampbellLendrum et al. 2003; McMichael et al. 2004). Countries with an annual GDP per capita of US$6,000 or more are assumed to have no additional risk of diarrhea (Tirado and Meerman 2012). Rural women in developing countries who depend on subsistence farming are often particularly disadvantaged (Lambrou and Piana 2006). They typically have limited access to productive assets for agriculture, decreasing their capacity to adapt to the impacts of climate change (Bryan and Behrman 2013). Decreased supply of safe water may also increase the labor burdens of women living in rural areas and developing countries, particularly in Africa and Asia (Parikh 2009). For instance, women are typically responsible for collecting water for household use and thus will spend more time and energy to collect water or may be forced to use unsafe water in the household, increasing risk of diarrheal diseases. Furthermore, increased pressure on women’s time also impacts their ability to appropriately care for infants and children, who require frequent feeding to meet their nutritional requirements, and elderly (Levinson et al. 2002; Tirado and Meerman 2012). Climate change may also increase the risk of emerging zoonosis – animal diseases that can be transmitted to humans – and will change the spatial and temporal distribution of vector-borne diseases such as malaria. The risk of emerging zoonosis may increase due to changes in the survival of pathogens in the

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environment; changes in migration pathways, carriers, and vectors; and changes in the natural ecosystems (Mills et al. 2010). The spatial and temporal distribution of vector-borne diseases such as malaria will also be disrupted. Climate change will have mixed effects on malaria distribution. In the long term, in some areas the geographical range will contract due to the lack of the necessary humidity and water for mosquito breeding. Elsewhere, the geographical range of malaria will expand, and the transmission season may be changed. It is estimated that in Africa climate change will increase the number of person-months of exposure to malaria by 16–28 % by 2100 (McMichael et al. 2004). Prevalence of these diseases affects utilization through a reduction in appetite, through loss of nutrients, and possibly through interfering with the body’s ability to absorb nutrients (WFP 2007).

Agricultural Production and Dietary Intake Climate change will have major impacts on agriculture and rural livelihoods. Pertaining to food utilization, climate change will likely decrease crop yields, alter the types of crops that are grown, and decrease the nutrient content of crops (Lobell and Burke 2010; Taub 2010). The impacts of climate change on agricultural yields, including crops, fish, and livestock, are increasingly well documented. Climate-related animal and plant pests and diseases and alien invasive aquatic species will reduce the quantities of food produced (FAO 2008). Evidence from models from the fourth IPCC assessment suggests that moderate local increases in temperature (1–3
C), along with associated CO2 increase and rainfall changes, can have small beneficial impacts on the yields of major rain-fed crops (maize, wheat, rice) and pastures in mid- to high-latitude regions. In seasonally dry and tropical regions, even slight warming (1–2
C) reduces yield. Further warming (above a range of 1–3
C) has increasingly negative impacts on global food production in all regions (Easterling et al. 2007). Decreased yields can impact nutrient intake of the poor and vulnerable by possibly decreasing supplies of highly nutritious crops and by promoting adaptive behaviors, substituting crops with a higher nutrient content for more sturdy less nutritious crops (Thompson and Cohen 2012; Lobell and Burke 2010). Furthermore, climate change could actually decrease the nutrient content of some crops. For instance, a study by Taub (2010) shows that elevated CO2 causes a decrease in protein concentrations of wheat, rice, and barley, and in potato tubers, by 5–14 % under elevated CO2. Furthermore, concentrations of nutritionally important minerals including calcium, magnesium, and phosphorus may also be decreased under elevated CO2. While the degree of decrease is small, coupled with yield decreases, the impacts could be significant (Lobell and Burke 2010). The populations most vulnerable to climate impacts are also the least able to effectively cope and are at the greatest risk of food insecurity, such as

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smallholder and subsistence farmers, pastoralists, traditional societies, indigenous people, coastal populations, and artisanal fisherfolk (Easterling et al. 2007; Tirado and Meerman 2012). Thus, faced with diminished productivity, vulnerable households not only are likely to decrease caloric consumption but will often substitute higher-value foods – such as proteins, fruits, and vegetables – for low-cost and low-nutrient starchy foods, decreasing the diversity of the diet and thus nutritional intake (Thompson and Cohen 2012). Furthermore, nutritional status has been linked to productivity, indicating that inadequate nutrition not only can diminish productivity for the current generation but also will decrease the future productivity of children impacted, thus completing the vicious cycle of vulnerability and food insecurity (Hoddinott et al. 2008; Schaible and Kaufmann 2007).

Conclusions There are many aspects of the relationship between climate change and food utilization that require more research to understand fully. However, the evidence we do have suggests not only that climate change is exacerbating food insecurity for the world’s poor but also that we must go beyond solutions promoting agricultural yields to addressing the broader health context and the complexities of crop science. And because those who are already vulnerable are least able to cope with or adapt to the impacts of climate change, women and other vulnerable groups must be considered in programs and policies to address the issue.

References Boko M, Niang I, Nyong A, Vogel C, Githeko A, Medany M, Osman-Elasha B et al (2007) Africa. In: van der Linden PJ, Hanson CE, Parry ML, Canziani OF, Palutikof JP (eds) Climate change 2007: impacts, adaptation and vulnerability, contribution of working group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge/New York, pp 433–467 Bryan E, Behrman J (2013) Community-based adaptation to climate change: a theoretical framework, overview of key issues and discussion of gender differentiated priorities and participation. International Food Policy Research Institute, Washington, DC Campbell-Lendrum D, Pruss-Ustun A, Corvalan C (2003) How much disease could climate change cause? In: McMichael A, Campbell-Lendrum D, Corvalan C, Ebi K, Githeko A, Scheraga J, Woodward A (eds) Climate change and human health: risks and responses. World Health Organization/World Meteorological Organization/UN Environment Programme, Geneva, pp 133–159 Checkley W, Epstein LD, Gilman RH, Figueroa D, Cama RI, Patz JA, Black RE (2000) Effect of El Nin˜o and ambient temperature on hospital admissions for diarrhoeal diseases in Peruvian children. Lancet 355(9202):442–450, http://www.ncbi.nlm.nih.gov/pubmed/10841124 Confalonieri U, Menne B, Akhtar R, Ebi KL, Hauengue M, Kovats RS, Revich B, et al (2007) Human health. In: Parry M, Canziani OF, Palutikof JP, van der Linden PJ, Hanson CE (eds) Climate change 2007: impacts, adaptation and vulnerability (Contributi.). Cambridge University Press, Cambridge, UK, pp 391–431

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Easterling W, Aggarwal P, Batima P, Brander KM, Erda L, Howden SM, Kirilenko A et al (2007) Food, fibre, and forest products. In: Parry ML, Canziani OF, Palutikof JP, van der Linden PJ, Hanson CE (eds) Climate change 2007: impacts, adaptation, and vulnerability, contribution of working group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge/New York, pp 273–313, http://ipcc-wg2. gov/AR4/SOD/Ch05.pdf Ecker O, Breisinger C (2012) The food security system: a new conceptual framework. International Food Policy Research Institute, Washington, DC, http://ideas.repec.org/p/fpr/ ifprid/1166.html FAO (2008) An introduction to the basic concepts of food security. FAO, Rome Food and Agricultural Organization of the United Nations (2008) Food safety and climate change. FAO high level conference on food security and the challenges of climate change and bioenergy. Food and Agricultural Organization of the United Nations, Rome Hoddinott J, Maluccio JA, Behrman JR, Flores R, Martorell R (2008) Effect of a nutrition intervention during early childhood on economic productivity in Guatemalan adults. Lancet 371(9610):411–416, http://www.ncbi.nlm.nih.gov/pubmed/18242415 Kovats RS, Edwards SJ, Hajat S, Armstrong BG, Ebi KL, Menne B (2004) The effect of temperature on food poisoning: a time-series analysis of salmonellosis in ten European countries. Epidemiol Infect 132(3):443–453, http://www.pubmedcentral.nih.gov/ articlerender.fcgi?artid¼2870124&tool¼pmcentrez&rendertype¼abstract Kundzewicz ZW, Mata LJ, Arnell NW, Do¨ll P, Kabat P, Jime´nez B, Miller KA et al (2007) Freshwater resources and their management. In: van der Linden PJ, Hanson CE, Parry ML, Canziani OF, Palutikof JP (eds) Climate change 2007: impacts, adaptation and vulnerability, contribution of working group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge/New York, pp 173–210 Lambrou Y, Piana G (2006) Energy and gender issues in rural sustainable development. Food and Agriculture Organization of the United Nations, Rome Levinson M, Halpern O, Mahmud Z, Chowdhury S, Levinson F (2002) Nutrition-related caring practices and women’s time constraints: a study in rural Bangladesh. The Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy Food Policy and Applied Nutrition Program (18). http://ideas.repec.org/p/fsn/wpaper/18.html Lobell D, Burke M (2010) Climate change and food security: adapting agriculture to a warmer world. Springer, Dordrecht/New York, http://www.worldcat.org/title/climate-change-and-foodsecurity-adapting-agriculture-to-a-warmer-world/oclc/630107791 McMichael A, Campbell-Lendrum D, Kovats S, Edwards S, Wilkinson P, Wilson T, Nicholls R, et al (2004) Global climate change. In: Ezzati M, Lopez AD, Rodgers A, Murray CJL (eds) Comparative quantification of health risks global and regional burden of disease, vols 1, 2. World Health Organization, Geneva, pp 1543–1649 Meehl GA, Stocker TF, Collins WD, Friedlingstein P, Gaye AT, Gregory JM, Kitoh A et al (2007) Global climate projections. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M et al (eds) Climate change 2007: the physical science basis. Contribution of working group I to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge/New York, pp 747–846 Mills JN, Gage KL, Khan AS (2010) Potential influence of climate change on vector-borne and zoonotic diseases: a review and proposed research plan. Environ Health Perspect 118(11):1507–1514. doi:10.1289/ehp.0901389 Parikh J (2009) Towards a gender-sensitive agenda for energy, environment and climate change. Division for the Advancement of Women, United Nations, Geneva Schaible UE, Kaufmann SHE (2007) Malnutrition and infection: complex mechanisms and global impacts. PLoS Med 4(5):e115. doi:10.1371/journal.pmed.0040115 Swindale A, Bilinsky P (2006) Household Dietary Diversity Score (HDDS) for measurement of household food access: Indicator guide. Food and Nutrition Technical Assistance . . ., Washington DC, p Version 2. Washington DC. ftp://190.5.101.50/DISCO 2/SRV-SQL/

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Nueva carpeta/doc lili bakup6654444/LILY/Monitoreo y Evaluacion/FANTA/fanta HDDS_Mar05 DIVERSIFICACION.doc Taub DR (2010) Effects of rising atmospheric concentrations of carbon dioxide on plants. Nat Educ Knowl 3(10):21, http://www.nature.com/scitable/knowledge/library/effects-of-risingatmospheric-concentrations-of-carbon-13254108 Tirado M, Cohen M, Aberman N, Meerman J, Thompson B (2010) Addressing the challenges of climate change and biofuel production for food and nutrition security. Food Res Int 43(7):1729–1744 Tirado MC, Meerman J (2012) The impact of climate change and bioenergy on nutrition. In: Thompson B, Cohen MJ (eds) The impact of climate change and bioenergy on nutrition. Springer Netherlands, Dordrecht, pp 43–60. doi:10.1007/978-94-007-0110-6 Thompson B, Cohen MJ (eds) (2012) The impact of climate change and bioenergy on nutrition. Springer/FAO, Dordrecht/Rome Trenberth KE, Jones PD, Ambenje P, Bojariu R, Easterling D, Tank AK, Parker D et al (2007) Observations: surface and atmospheric climate. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M et al (eds) Climate change 2007: the physical science basis. Contribution of working group I to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge/New York, pp 235–336 Weinga¨rtner L (2005) The concept of food and nutrition security. Achieving food and nutrition security. German International Cooperation Organization. http://www.foodsec.org/DL/course/ shortcourseFA/FR/pdf/food_reader_engl.pdf#page¼23 World Food Programme (2007) World hunger series 2007: hunger and health. Earthscan, London WFP (2009) Emergency food security assessment handbook. World Food Programme, Rome, pp 68–70 World Bank (2008) Agriculture and poverty reduction. Policy. The World Bank, Washington DC. http://sds.ukzn.ac.za/files/SDS_PB3_avocado_8pgLR.pdf Zimmerman AM, DePaola A, Bowers JC, Krantz JA, Nordstrom JL, Johnson CN, Grimes DJ (2007) Variability of total and pathogenic Vibrio parahaemolyticus densities in northern Gulf of Mexico water and oysters. Appl Environ Microbiol 73(23):7589–7596. doi:10.1128/AEM.01700-07

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Benjamin Graeub, Samuel Ledermann, and Hans R. Herren

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seeds and Extreme Weather Shocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cross-References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

The adaptation of the food system to climate change is one of the major challenges of our time. This transformation of the food system to adapt to and mitigate climate change has to occur across multiple scales: from the farm to the policy level. At the farm level, small-scale farmers’ abilities to cope with the increasing occurrences of extreme weather events – such as droughts, floods, storms, and heat waves – as well as deteriorating quality of soils and lower availability of water will be largely determined by the ability to adopt technologies that are knowledge intensive as opposed to capital intensive. It is in this context that a global consensus has arisen that business as usual is not an option and the way forward needs to build on and strengthen agroecological, sustainable agricultural methods (see McIntyre et al. 2009; UNEP 2012) that enable climate change mitigation. Apart from the necessary shifts in the management of

B. Graeub • S. Ledermann (*) Biovision Foundation for Ecological Development, Zurich, Switzerland e-mail: [email protected]; [email protected] H.R. Herren Millennium Institute, Washington, DC, USA Biovision Foundation, Zurich, Switzerland e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_122, # Springer Science+Business Media Dordrecht 2014

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the different resources, adaptation and mitigtation strategies at a policy level will be crucial. General knowledge on more sustainable consumption and production patterns needs to be improved. This includes the knowledge of policy makers through innovative policy planning tools and promoting policies that increase the adaptability of the global food system. This article outlines a range of existing viable technologies and knowledge. Keywords

Agroecology • Sustainable agriculture • Adaptation strategies • Sub-Saharan Africa • Social capital

Definition The adaptation of the food system to climate change is one of the major challenges of our time. IFPRI (Nelson et al. 2009) estimates that US$ 7 billion in funding per year is needed to counteract the impact of climate-related shocks on nutrition, with 40 % – approximately US$ 3 billion – to be invested in sub-Saharan Africa alone. This transformation of the food system to adapt to climate change has to occur across multiple scales: from the farm to the policy level. At the farm level, small-scale farmers’ abilities to cope with the increasing occurrences of extreme weather events – such as droughts, floods, storms, and heat waves – as well as deteriorating quality of soils and lower availability of water will be largely determined by the ability to adopt technologies that are knowledge intensive as opposed to capital intensive (see Fig. 84.1). It is in this context that a global consensus has arisen that business as usual is not an option and the way forward needs to build on and strengthen agroecological, sustainable agricultural methods (see McIntyre et al. 2009; UNEP 2012). Apart from the necessary adaptations in the management of the different resources, adaptations at policy level will be crucial. General knowledge on more sustainable consumption and production patterns needs to be improved. This includes the knowledge of policy makers through innovative policy planning tools and promoting policies that increase the adaptability of the global food system. This article outlines technologies and knowledge necessary to adapt to the negative effects of climate change at the farm and policy level. It does so by focusing on the relevant resources – soil, water, and seeds – and the knowledge and technologies necessary to adapt their management. Furthermore, it looks at the impact of extreme weather events – due to climate change expected to occur both more frequently and more intensely – and what measures are necessary to tackle them.

Soil Soils are essential: not only are they crucial in adapting to consequences of climate change but also in climate change mitigation relevant to the food

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SRI Social Capital/ Governance

Participatory Seed Breeding

Nitrogen-fixation

Social Safety nets

Knowledge Requirements

Planting Dates

Knowledge Dissemination (ICT) Conventional Breeding

Agro-forestry Cover crops/ Green manure

IPM

Compost

Zero/Reduced Tillage

Intercropping/ Crop rotations

GIS/ Remote Sensing Micro-Drip Irrigation

Perennial crops

Drip Irrigation

Adaptations by Type Seeds

Soil

Water

Structural

Infrastructure

Technological Requirements

Fig. 84.1 Different adaptations and their knowledge and technological requirements

system (IPCC 2007). There are now clear indications that different farming techniques lead to changes in concentrations, stocks, and sequestration rates of carbon in the topsoil (Muller 2012). Specifically, agroecological practices, agroforestry, as well as optimal irrigation and nitrogen inputs increase the soil’s capacity to sequester carbon and thus have a mitigating effect on greenhouse gas (GHG) emissions (Muller 2012). According to the UN’s Food and Agriculture Organization (FAO 2005), anthropogenic (human) practices have a greater impact on soils than climatic changes. It is therefore important that adaptation to climate change takes into account and addresses predictable changes from human management. With pressure on soils expected to increase, the resilience and health of soils becomes central to food security under the climate change challenges. Current estimates of the impact of climate change on soils are expected to increase its existing vulnerability. According to the IPCC (2007) up to a third of coastal land and wetlands might be lost until 2100, driving a loss of land due to sea-level rise. Higher frequency and intensity of extreme weather events – such as heat waves and windstorms – are expected to lead to proximate increases in soil erosion and runoff and ultimately a reduction in soil fertility. Furthermore, the increased turnover rates of organic matter under higher temperatures lead to further (negative) changes in soil composition (Olesen and Bindi 2002). Adaptation to these changing environments, induced by anthropogenic and climatic changes, mainly aims at increasing the soil fertility via gains in the amount of organic matter in the soil, with the added benefit of obtaining higher water retention rates. Agricultural practices (FAO 2005) include the use of compost,

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integration of cover crops or green manure, potentially combined with zero or reduced tillage under a multi-year crop rotation pattern. Moving beyond the yearly cycle, perennial forage crops and agroforestry, as well as farm management methods that avoid overgrazing or the burning or removal of crop residues are also of great importance. One of the main aims of these (combined) interventions is to halt soil erosion by establishing ground cover year round via an integrated plant nutrient management system (FAO 2005). As noted above, knowledge and technologies necessary for these adaptations are complex. Further research is necessary on the (marginally understood) soil ecosystem and ensuring that easy-to-use and locally relevant knowledge is put into action by farmers. This includes drawing upon farmers’ own indigenous adaptation strategies – even latent ones. A key component, as a result, is not only to disseminate successful knowledge-intensive strategies but also strengthen farmers’ abilities to act as innovators and their capacity to sustainably adapt to changes in the long run. In this context FAO, together with external partners, is currently developing a participatory Self-evaluation and Holistic Assessment of climate Resilience of farmers and Pastoralists (SHARP) tool. The participatory tool will be used to identify opportunities for improvement as well as avenues to promote better practices for food producers. It creates an opportunity for farmers to learn about sustainable practices that can improve their ability to adapt to climate change.

Water Effects of climate change on water usage are expected mainly through higher temperatures and different precipitation patterns. Adaptations will be necessary not only due to climate change but also due to higher demand for domestic and industrial uses of water. In order to reach the goal of food and nutrition security for all, a more efficient use of water in agricultural production will be necessary. This is not only the case in irrigated agriculture – research indicates climate change may lead to less irrigated agriculture (Reilly et al. 2003) – but especially for rain-fed agriculture. To achieve this goal of more efficient water use in agriculture, there is a need for three main avenues of adaptation. First, technological improvements of water efficiency in irrigated agriculture such as drip or micro-drip irrigation are necessary. These well-developed irrigated agriculture technologies – both applied on the surface and directly at the roots – save considerable amounts of water while resulting in equal or higher yields than conventional irrigation schemes. Second, agricultural techniques – as described above – exist to improve the soil’s ability to retain water or have positive effects on water efficiency while simultaneously increasing yields (e.g., “System of Rice Intensification (SRI),” UNEP 2012) and increasing the provisioning of ecosystem services overall (Milder et al. 2012). Third, evidence exists that apart from technological solutions, social capital referring to the capacity of groups to organize themselves effectively can be a highly effective method to improve natural resources management. This is especially relevant for the commons such as shared land or water (Ostrom 1992).

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These needs for adaptation show that while technological improvements in irrigation schemes are still needed (i.e., improved drip irrigation schemes), the development of locally adapted and effective agricultural practices needs to build on social capital. As a result, complex gaps need to be addressed when confronting climate change, including a more even distribution of access to water by smallholders and overall improvement of governance of this increasingly limited resource. Furthermore, the question of knowledge dissemination is once again crucial to ensure that techniques can be applied by farmers.

Seeds and Extreme Weather Shocks As stated at the outset, adaptation to climate change is multi-scalar. Increased occurrences of extremes – such as droughts, floods, and heat waves – will need to be managed by knowledge, as opposed to solely capital-intensive technologies at the farm level. This will be especially the case in sub-Saharan Africa where the majority of the population continues to depend on agriculture as their main source of income and has low access to capital and markets. While multifaceted policy strategies – including improved data gathering, largescale investments in road infrastructure, and value-adding enterprises for market access – are developed, few are as essential as developing crop varieties that are adapted to climate change. These include drought-, pest-, and disease-tolerant crop varieties – saved from the bounty of farmer’s varieties (land races) that have been selected to survive difficult weather conditions over the past centuries – and taking these into improvement and multiplication programs. This can be achieved by strengthening existing or dormant local knowledge and expertise on indigenous seed varieties via increased knowledge sharing and capacity building for participatory seed breeding projects and the development of local seed production and distribution system (preferably farmer owned). These considerations apply also to the animal sector, where more diversity is equally needed to promote resilience. Integrating new advances in spatial analysis – i.e., remote sensing and GIS – can provide significant advances in identifying stress-tolerant varieties for future growth conditions from within a certain region or seed banks held in trust across the globe (see Bioversity International 2013). In addition to crop relocation, improved knowledge on shifts in climate will allow for adjustments of planting dates and crop varieties within a country and beyond. Advanced remote sensing techniques have also been instrumental to create early warning systems against the increased pest pressures faced by farmers, such as locusts but also fungi (Cressman and Hodson 2009). Adaptation and mitigation strategies of transboundary threats call for regional solutions and subsequent high requirements for collaboration at the policy level. At the farm level, multiple proven abilities exist to adapt to these challenges. These include the adaptation of integrated pest management – IPM – and increasing agricultural biodiversity (UNEP 2012). The former – IPM – is slowing down pest resistance while simultaneously increasing net profits due to reduced spraying costs. The latter can reduce the ecosocial vulnerability resulting due to monocropping by

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planting multiple crops for subsistence and markets but also improve overall sustainability. Such knowledge- and labor-intensive adaptation strategies – also outlined earlier – include, but are not limited to, intercropping, cover crops, crop rotations including leguminous and pasture crops, and where appropriate integrated into agroforestry systems with nitrogen-fixing trees. As shown in the case of push-pull technology developed in Western Kenya (Khan et al. 2008), intercropping leguminous desmodium in between maize, with a border crop of Napier grass, not only reduces yield losses to maize stem borers and Striga weed, it also improves soil fertility via its nitrogen-fixing properties. The Napier grass and the desmodium furthermore are valuable fodder for milk cows. The key challenge with agroecological solutions, as a result, is the ability to disseminate this knowledge to farmers in an efficient matter. Innovative information and communication technologies (ICT) can help, but especially extension services together with Farmer Field Schools existing on the ground need to be strengthened. One of the largest remaining challenges is the requirement for adaptation strategies, as both flooding and droughts are expected to increase. Tackling these extremes with one single panacea, such as adapted seed varieties, is impossible and needs to be supported by agronomic practices that improve soil fertility and resilience. Furthermore, additional mechanisms need to be put in place in order to create a safety net for farmers, such as via crop insurance or better access to national and international markets. Even with the interannual volatility faced due to climate change, intraannual volatility felt in the form of supra-regional impacts from price shocks has to be addressed. Moving beyond the field, farmers need new innovative technologies to reduce their postharvest losses, thus enabling them to better manage volatility and risk, while global citizens are called upon to adjust their consumption patterns. In the face of the complexity of the challenges resulting from climate change, only medium- and long-term solutions that tackle the problems at their roots will bring about the needed adaptation potential. A systemic analysis of the situation prior to undertake corrective actions is a must, as only by having a thorough understanding of the present agriculture and food system can a new one evolve that will offer the needed resilience. As depicted in Fig. 84.1, the different adaptations outlined in this chapter have varying degrees of technological and knowledge requirements. According to the types of adaptation depicted, it is clear that farm-level adaptation are clustered towards the upper-left hand corner, reflecting lower technological requirements yet marked by higher knowledge requirements. These contrast with several adaptation strategies at the policy level – clustered towards the right side, reflecting higher technological requirements – which focus on developing structural and global solutions that have an impact beyond the farm. However, even in these cases – such as efforts in breeding or developing early warning systems via remote sensing – the requirements in regard to knowledge and especially collaboration are high. As result, we strongly believe that it is only when local solutions at the farm level meet up with global action at the policy level that the full potential of the knowledge and technologies to adapt to climate change can be harvested.

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Cross-References ▶ Agroecology: Adaptation and Mitigation Potential and Policies for Climate Change ▶ Food and Water and Climate Change ▶ Global Change and Terrestrial Ecosystems, Introduction ▶ Impacts of Global Change on Crop Production and Food Security ▶ Land Management Options for Mitigation and Adaptation to Climate Change

References Bioversity International (2013) Seeds for Needs. http://www.bioversityinternational.org/research/ sustainable_agriculture/seeds_for_needs.html. Accessed 24 Apr 2013 Cressman K, Hodson D (2009) Surveillance, information sharing and early warning systems for transboundary plant pests diseases: the FAO experience. Arab J Plant Protect 27:226–232. http://www.asplantprotection.org/PDF/AJPP/27-2_2009/226-232.pdf. Accessed 24 Apr 2013 FAO (2005) The importance of soil organic matter. FAO Soils Bull 80. FAO, Rome IPCC (2007) Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. IPCC, Geneva, Switzerland. http://www.ipcc.ch/ publications_and_data/ar4/syr/en/contents.html. Accessed Apr 2013 Khan ZR, Midega CAO, Njuguna EM, Amudavi DM, Wanyama JM, Pickett JA (2008) Economic performance of the “push–pull” technology for stemborer and Striga control in smallholder farming systems in western Kenya. Crop Prot 27(7):1084–1097 McIntyre B, Herren H, Wakhungu J, Watson RT (eds) (2009) Agriculture at the crossroads: international assessment of agricultural knowledge, science and technology for development. Island Press, Washington, DC Milder JC, Garbach K, DeClerck FAJ, Driscoll L, Montenegro M (2012) An assessment of the multi-functionality of agroecological intensification. EcoAgriculture Partners Muller A (2012) Agricultural land management, carbon reductions and climate policy for agriculture. Carbon Manag 3(6):641–654 Nelson GC, Rosegrant MW, Koo J, Robertson R, Sulser T, Zhu T, Ringler C, Msangi S, Palazzo A, Batka M, Magalhaes M, Valmonte-Santos R, Ewing M, Lee D (2009) Climate change impact on agriculture and costs of adaptation, Food policy report. IFPRI, Washington, DC Olesen JE, Bindi M (2002) Consequences of climate change for European agricultural productivity, land use and policy. Eur J Agron 16(4):239–262 Ostrom E (1992) Crafting institutions for self-governing irrigation systems. ICS Press, Richmond Reilly J, Tubiello F, McCarl B, Abler D, Darwin R, Fuglie K, Hollinger S, Izaurralde C, Jagtap S, Jones J, Mearns L, Ojima D, Paul E, Paustian K, Riha S, Rosenberg N, Rosenzweig C (2003) U.S. agriculture and climate change: new results. Clim Change 57:43–69 UNEP (2012) Avoiding future famines: strengthening the ecological foundation of food security through sustainable food systems. UNEP, Nairobi. http://www.siani.se/sites/clients. codepositive.com/files/document/unep_food_security_report_2012.pdf. Accessed 24 Apr 2013

Additional Recommended Reading International Assessment of Agricultural Knowledge, Science and Technology for Development (IAASTD). www.agassessment.org Montpellier Panel (2012) Growth with resilience: opportunities in African agriculture. Agriculture for impact, London. https://workspace.imperial.ac.uk/africanagriculturaldevelopment/Public/ Montpellier%20Panel%20Report%202012.pdf

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Janice Jiggins

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Need for Transformational Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Push-Pull Approaches to Crop Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agroforestry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Perennial Cereals and Other Crops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Potential for Faster, Stronger Effort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mobilization of New Funding and Action Modalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Policy-Driven Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Definition The chapter lays out the reasoning and evidence for transition in both industrial and developing countries toward agricultures and food systems based on agroecological principles, in order to develop the resilience and mitigation potential of farming under climate change. Agroecology is defined and illustrated by means of three examples with proven potential to bring about transformational change: “pushpull” approaches to crop protection, weed control, and soil fertility management; agroforestry; and perennial crops. Some of the key barriers to wider, faster adoption of agroecological options are noted. Novel funding and action arrangements, regional food movements, and policy-led changes are identified as three powerful drivers of agroecological responses to climate change.

J. Jiggins Knowledge, Technology and Innovation Section, Communication, Philosophy, Technology (CPT), Wageningen University, Wageningen, The Netherlands e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_123, # Springer Science+Business Media Dordrecht 2014

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The Need for Transformational Change The percentage of global investments directed to agriculture dropped from 16 % to 4 % between 1980 and 2010, according to World Bank data. Nonetheless, food price shocks, animal disease outbreaks, contamination of traded food stuffs, the mounting evidence of the actual and potential harmful environmental impacts of farming, and climate change disruptions to production have prompted numerous countries in the last decade to commission parliamentary and scientific studies of the future of agriculture and food (including Australia, the USA, France, Germany, Ireland, the UK, China). Regional bodies (e.g., in sub-Saharan Africa and the EU) have commissioned similar studies, as have intergovernmental consortia (e.g., IAASTD) and United Nation agencies (e.g., UNEP, FAO, IFAD, UNCTAD, WTO, IFAD). These have been accompanied by innumerable specialist policy, economic and scientific studies, as well as by statistical, scenario, and modelling exercises. The weight of the evidence indicates that food and farming are on the wrong pathway. However, the evidence has not given rise to consensus about what to do. Fundamentally this is because neither “scientific methods of inquiry” nor the “evidential facts” speak for themselves. They do not give rise to uncontested choices about what should be done. Questions of what should be done, by whom, and how are inflected by differing political, commercial, and livelihood interests, divergent contexts entangled in both local and global histories, distinctive food cultures, and ethical values. Deciding what to do, moreover, requires a capacity to understand the interconnections among an exceptionally wide range of diverse information, experience, practices, disciplines, risks, and highly specialized sciences. This provides ample scope not only for informed dissent but also for divergent political choices concerning what the preferred alternatives are. A few areas of consensus nonetheless have emerged: • The United Nations Development Programme’s 2013 Human Development Report sets out the considerable, sustained, and in many countries accelerating progress made over the last two decades for the vast majority of the world’s people in terms of education, health, and income. The progress is not accidental; it is directly and indirectly related to government policies and public investments. • Production of adequate amounts of affordable, nutritious food is a necessary but not sufficient condition for easing hunger. Whether increased agricultural production contributes to the easing of poverty and hunger, or not, depends on where, by whom, and the way in which the effort is made. If yield and output were the only measures, there is more than enough primary food grown and traded to feed current populations. Primary yield has risen to historically unprecedented levels across all major food and fodder categories, and aggregate surplus has been sustained at rates considerably higher than population growth. However, the commonly posed question “can we feed the 9 billion people?” forecast to be alive by mid-century is the wrong question because the answer can only be: it all depends on the choices that are made (Tomlinson 2013).

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For instance, feeding protein crops (such as wheat, maize, and an estimated 90 % of the global soy harvest) to intensively reared animals and poultry converts relatively cheap-to-produce food that people can eat into expensive meat products but generates a larger greenhouse gas footprint, creates significant and costly pollution, requires costly and intensive animal health management (giving rise to new risks of animal welfare, human and animal health), and consumes unsustainable amounts of water that people need for drinking. The question is rather how much of what, for whom, where, how, and with what consequences? • The effort to sustain the rate of increase in yield, and small farmers’ livelihoods, has given rise to second-order problems of unprecedented magnitude that are on the brink of escaping individual and societal management. The second-order problems are interdependent and coevolving across multiple spatial and temporal scales. Thus agriculture cannot adapt in an ordered fashion to climate change, nor can the mitigation potential of agriculture be realized, by means of simple technology substitutions alone (The Royal Society 2009). The following points highlight these problems and lay the basis for the illustrations of agroecological transitions that follow: • Agri-food systems make significant contributions to greenhouse gas emissions as the aggregate effect of the choices made in the development of and technologies used in agriculture and food systems. Agricultural activities are estimated to account for some 15 % of global greenhouse gas emissions (methane, nitrous oxide, carbon dioxide), chiefly as a result of land use and soil management practices, followed by methane from livestock, wetland rice production, and manure management and by land clearing and biomass burning. Carbon-rich grasslands and forests in temperate zones have been replaced over time by annual crops that have much lower capacity to sequester carbon. The technical potential for carbon sequestration in the agricultures of the EU 27 in 2007 has been estimated at about 16 MT carbon dioxide equivalent/year, representing about 37 % of all emissions in the EU; the achievable potential, without permanent management changes to farming systems, is probably much lower and in any case would make only a small global impact. • Mass degradation of landscapes and soils, and desertification, tied to monocropping, mechanized total tillage, deforestation, and land competition. • Global-scale destruction of hydrological systems, tied to irrigation technology, fossil fuel and fertilizer subsidies, agrochemical pest control, and salination of soils. Farming practices in poor countries are only part of the problem. A recent study in the USA of water conditions at 2,000 sites sampled in 2008 and 2009 found poor conditions at more than half of the sites, with nutrient pollution from agriculture as the major cause: 40 % of rivers and streams rated poor because of high phosphorus levels and 28 % as poor for excessive nitrates (Tesoriero et al. 2013). • Loss of agro-biodiversity and locally controlled seed systems, tied to the rise of corporate power and biotechnology and the intrusion of private intellectual property rights into agri-food systems.

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• Wide-scale impairment and death by neurotoxins used in agrochemicals. Highly toxic pesticides kill more people globally than wars and homicides combined. • Malnutrition, leading to undernourishment for around 1bn people and to overweight and obesity for more than 1.4 bn people. Both are tied to the production, marketing, and consumption of insufficient and/or inappropriate foods and foods deficient in micronutrients, giving rise to labor and cognitive impairments and other health problems that are irreversible over the short term and on scales that no private or public health system can afford to treat. • Extended trade and food chains of increasing complexity that can no longer be sufficiently regulated to prevent fraud or give warning of emergent risks. The task is not to meet the current and upcoming challenges by intensifying what are clearly the wrong things to be doing but to move as rapidly as possible toward alternatives. Agroecology, although an imprecise term, provides the necessary frame for thinking about developing and bringing into being alternative ways forward in agricultural production. It has both scientific and practice dimensions that incorporate the multidisciplinary study and management of the interactions among plants, animals, insects, people, and natural resources, within agricultural and food systems and farming landscapes. By bringing ecological principles to bear, its practitioners pursue the normative goal of harmonizing productivity, stability, sustainability, and equitability. The remainder of this chapter first provides three examples framed by agroecology from the production side, either that already have more than local significance or that offer the prospect of radical transformations of a helpful kind. The examples have been chosen because, taken together, they open up prospects for radical agroecological transformations of agriculture and farm landscapes. They also allow some of the key barriers to the necessary transitions to be brought into view. The chapter concludes by further pinpointing three emerging drivers of transitions, where significantly increased effort, investment, and creative problem-solving seem necessary and possible.

Push-Pull Approaches to Crop Protection Beginning in 1993, scientists at icipe (International Centre of Insect Physiology and Ecology, based in Nairobi), KARI (the Kenya Agricultural Research Institute), other national partners and nongovernment organizations, and Rothamsted Research (UK) have developed a “push-pull” technology that simultaneously addresses the major constraints to cereal-based farming in sub-Saharan Africa (SSA). Maize, sorghum, millets, and rice are the main cereal crops grown for both food and cash by millions of smallholders throughout SSA. Average yields are less than 2 t a hectare, largely because of a host of biotic constraints that include insect pests (notably, stem borers) and the parasitic week Striga, as well as land degradation and poor soil fertility. Poor harvests mean low incomes and the constant risk of food shortages for households and high cereal import bills for

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national governments. Management practices based on purchase of insecticides and fertilizers have proven too costly for the majority of smallholders and, where used, in practice have caused unacceptable environmental and human health problems. The principles of push-pull are simple. The cereals are intercropped with a plant such as desmodium that repels the insect pests away from the crop. Other plants, such as Napier grass, are planted around the border to attract the pests out of the crop and pull in predator insects. The desmodium fixes nitrogen in the soil and also first stimulates the germination of Striga seeds but then inhibits their growth (Midega et al. 2013). Typical yields in smallholder farming systems in Kenya for cereals grown with and without push-pull are up to 4 t/ha compared to 1.5–2.5 t/ha, respectively, for maize; 2.4 and 1.9 t/ha, respectively, for sorghum; and 4 and 2.1 t/ha, respectively, for finger millet. The intercrop and border grasses provide high-quality animal fodder. The companion plant species are perennial and help conserve soil moisture and improve soil health. Through propagation of the grasses, and by harvesting desmodium seeds, some farmers and communities are earning additional income through sales to other farmers. Ongoing field studies and monitoring effort allows scientists to identify and respond to emergent problems (such as Napier stunt disease). Farmers themselves are making notable contributions to push-pull. They helped initially to identify suitable varieties of the companion plants. Recently they have helped identify and test drought-tolerant desmodium varieties that allow the technology to spread into drier areas and together with the scientists have begun to incorporate other crops (such as beans). From its initial focus in eastern Africa, push-pull is spreading rapidly to other parts of SSA, through farmer-to-farmer sharing and training (assisted by innovative use of modern communication technologies), farmer field schools, and more conventional extension methods. Today, over 35,000 farmers are using push-pull; the target is one million by 2020. For a habitat management strategy, the number of adopters is impressive, yet the numbers are insignificant compared to the potential. The missing element is a social mechanism of sufficient power and reach to drive adoption forward. With an increasing number of countries no longer investing in the delivery of advice and extension support through public services, some expect market actors and commercial companies to step in. A few have. The Western Seed Company Ltd, one of the main private seed producers in East Africa, is selling commercial quantities of desmodium seed, produced through a network of contracts with individual farmers and farmer groups. However, push-pull does not offer significant opportunities for product marketing nor can it be protected by the kinds of exclusive intellectual property rights that would attract the dominant international corporations. Indeed, insofar as it is effective and becomes widespread, it can be viewed as a potentially damaging competitor to the insecticide and fertilizer sales of the corporate leaders. Many researchers thus consider the lack of development of economic and organizational models that could make such solutions as push-pull a mainstream practice, the more significant barrier to sustainable agriculture and food systems than the technology alone (Renwick et al. 2012).

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Agroforestry Forests are estimated to store up to 40 % of terrestrial carbon. Although temperate regions are slowly restoring forest cover, the replacement of forests by annual crops and other uses throughout the world has increased greenhouse gas emissions and led to significant and largely detrimental changes in soil condition and capacity, in hydrological cycles and flood management, and in biodiversity. Deforestation also threatens the loss of forest-based products that support the livelihoods of some 1.5 bn people. Agroforestry is an elastic term that encompasses multiple pathways to the reversal of these trends (Leakey 2012). Agroforestry’s carbon sequestration contribution and potential is substantial. Within the European Union, agroforestry stands out very clearly as the measure with the highest potential for mitigation (Aertsens et al. 2012). In a comparison of the contribution to climate change mitigation of five types of organic agricultural systems in countries as diverse as the Netherlands and Egypt, an organic cocoa-based agroforestry system in Indonesia performed best of all, sequestering 11 t carbon/hectare/year. Examples of agroforestry include the sustainable exploitation of the products of the extensive natural damar forests in Indonesia and the domestication and modern management of species little known outside the areas where they are locally known and used (such as Garcinia Kola, whose fruits, nuts, exudates, bark, and gum are used throughout West and Central Africa in a variety of hygiene, medical, and household uses). Tree species that capture atmospheric nitrogen and fix it in the soil are key elements in new designs for “evergreen agricultures” in sub-Saharan Africa (Garrity 2009; Badege et al. 2013). Gliricidia in trials with smallholder farmers in Zambia, Malawi, and an increasing number of neighboring countries, for example, has brought record maize yields, doubling the harvest obtained from use of commercial fertilizers and increasing sevenfold the yield obtained when maize is grown without any fertilizer. Over a quarter of a million households in Malawi alone have adopted the practice of intercropping with Gliricidia and nitrogen-fixing shrubs. Faidherbia albida is an acacia species that can last for up to 75–100 years. It not only fixes nitrogen but sheds its leaves during the early rainy season, thus increasing its compatibility with food crops. It has been incorporated into food cropping systems by farmers in many of the drier regions of Africa, including Senegal, Mali, Burkina Faso, Niger, Chad, Sudan, and Ethiopia; Malawi and Tanzania in southern Africa; and parts of northern Ghana, Nigeria, and Cameroon. Agronomists and farmers are working together throughout these areas to develop and test improved systems for establishment, pruning, and intercropping and that incorporate faster-growing nitrogen-fixing species to provide fertility in the 3–5 years it takes for Faidherbia albida to provide significant benefits. The effects on the environment, soils, water regimes, insect life, and other forms of biodiversity are also being monitored. Development of agroforestry systems is expanding the range of cereals and other food crops, as well as food and nonfood products that enter modern markets. This is

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an important consideration under climate change given that the world’s commercial food supply currently rests on five crops (maize, rice, wheat, soy, and potatoes) that face significant yield losses under predicted changes to temperature and rainfall. Agroforestry developments linked to product development and marketing lend themselves to wider adoption of geographic indications, as well as communityowned plant variety rights and territorial-based rights, as forms of protected but widely shared intellectual rights. These share the intention and potential to conserve agroecological functioning, sustain favored landscape features, and provide a worthwhile return.

Perennial Cereals and Other Crops Perennial grains, legumes, and oil seeds, combined with sustainable practices and novel farming systems, offer the prospect of ending the numerous conflicts between increasing food production and safeguarding ecological well-being. Some 5–10,000 years’ ago, our ancestors collected and selected seed from perennials for the development of annual cropping systems. Annuals have ephemeral, typically low-density root systems, with a lower capacity than perennials to nurture microbial life systems in soils and to optimize the use of nutrients and water. Some traditional and modern farming systems rely on techniques such as zero tillage to compensate for the weaknesses in annual cropping. It is estimated that currently about 100 million hectares are managed worldwide under minimum or zero tillage, mostly in the USA, Brazil, Argentina, Australia, Canada, and Paraguay in the areas of industrial commodity production. The practice can reduce erosion and improve soil structure in the top layers of the soil significantly. It has been hailed as an agroecological success story, but in industrial farming over a large scale, it requires increased use of toxic and polluting chemical inputs and leaves the lower soil levels unimproved. Organic farming methods for their part do not include use of toxic pesticides and may improve soil fertility but do not avoid the soil erosion and water problems consequent on tillage. Perennials grown for food, fodder, and grazing could avoid the consequences of basing the world’s food systems on annuals and resolve emergent problems such as salinity while increasing drought tolerance, soil health and fertility, and opportunities for carbon sequestration. Research groups and networks based in the USA, the UK, Sweden, China, and Australia, and in an increasing number of other countries, are at various stages of investigating, developing, and trialing perennial varieties of wheat, wheat grasses, rice, barley, sunflower, sorghum, and other crops. In the effort to recover perenniality from the precursors to today’s crop varieties, new disease resistance traits are being identified that open the way to further innovative pathways to disease management. Some prototype varieties (e.g., of rice) are already in field trials as mono-crops, others are emerging as dual-purpose crops for grazing and grain production or for use in intercropping systems that include a perennial grain and a nitrogen-fixing legume and, as in the push-pull system, plants that employ

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secondary metabolites that protect against parasitic weeds such as Striga. Further ahead lies the prospect of multi-species mixes that provide additional resilience in the face of climate change. Many of the advances in the understanding of perenniality could not have been gained without the tools and insights of the advanced genetic sciences. Varietal development of perennials is likely to emerge both from conventional breeding effort and genetic modification. With respect to current commercial GM crops, ownership of the associated techniques and genetic material is controlled by a handful of companies and protected by a range of exclusionary intellectual property rights (Renwick et al. 2012). Insofar as perennial crops are either vegetatively propagated or (in the case of grains, for instance) seed based, can strong private sector participation be expected to drive the uptake of perennials? Over time the transition to perennial systems seems likely to diminish the need for sales of chemical inputs and, once perennial systems are established, also of seeds themselves. Alternative intellectual property rights in the form for instance of contracts, open-source strategies, and public ownership of patents are under consideration, in order to put in place the kinds of rights that simultaneously encourage the spread of perennial crops while meeting the diverse needs of each country.

The Potential for Faster, Stronger Effort A question that emerges throughout this chapter is what might be the drivers of a systemic turn toward agroecology. As noted already, market-based actors clearly will play a part. In addition to participating in rolling out field-based options, pioneer companies already are developing so-called closed-loop systems, for instance, those for urban-based insect farming in which the insects feed off the wastes from supermarkets and provide high-quality proteins, vitamins, and minerals for poultry, fish, and some other types of livestock production. Other companies are developing greenhouse-based closed systems that combine, for example, tomato and tilapia production; make much more efficient use of water, heat, and space; rely on biological pest and disease management; reduce greenhouse gas emissions; do not release pollutants to the environment; allow comprehensive traceability and regulation of food safety; and bring production much closer to centers of high population density. However, the considerable vested interests in business as usual, as well as institutional inertia, offer formidable barriers to rapid and widespread change. Three dynamic sectors nonetheless are driving faster, wider transitions.

Mobilization of New Funding and Action Modalities Instances here include the group of American Foundations that have formed the New Venture Fund to amplify agroecological solutions in both industrial and developing countries. The Global Biodiversity Foundation, a not for profit based in the USA

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and UK, is negotiating bio-cultural community protocols with indigenous peoples and local communities throughout the world, to make an inventory of and protect and develop the livelihood potential of biodiversity within “community conserved areas.” The Caribbean Community Climate Change Centres, established in 2002 by regional governments, are coordinating and supporting collaboration among ministries, research agencies, farmers’ organizations, local governments, and civil society groups in bringing about systemic change in farming and food systems throughout the Caribbean. The Future Earth program, established in 2012, aims at developing the required knowledge for responding to global environmental change and supporting transformation toward global sustainability. One of its actions is centered on food systems, and one of its approaches includes transdisciplinarity to address problems, that is, including all actors in the research process. Regional food movements are emerging that create new opportunities for valuing and rewarding local seed security and conservation, bring new income opportunities for landscape and catchment management, create shorter value chains between producers and consumers, give value to foods of high nutritional and cultural importance, and create new opportunities for democratic decision-making about the balance among social justice, inclusive development, and economic growth. The Alliance for Food Sovereignty, for instance, has self-organized among eight nongovernment organizations and numerous civil society and consumer organizations, to develop regional food systems across the four states of Maharashtra, Orissa, Tamil Nadu, and Madhya Pradesh in India. In Ecuador the “canastas” movement is providing comparable evidence of citizens’ capacity to develop new kinds of commercial and cultural relationships in the market transactions among producers, processors, and consumers. Initiatives that are achieving impact at scale are to be found also in industrial countries. For example, under the combined leadership of civil society groups, farmers’ organizations, the research community, and the So¨derta¨lje local government in the Ja¨rna/So¨derta¨lje area of Sweden, a sustainable food society is emerging, based on agroecological principles, a commitment to 100 % advanced organic production within 10 years, and scientific understanding of landscape ecology. Other regions around the Baltic Sea in ten countries, supported by the EU, have embarked on similar transitions (www.beras.eu). Locally grown, tasty and wholesome food has become more widely available, at a price even low-income consumers can afford. A national supermarket chain is supporting the transition. Soil and water conditions are improving, and biodiversity is recovering its variety and abundance. New enterprises have been established in seasonal horticulture, distribution, retailing, catering, and tourism.

Policy-Driven Change Policy-led innovation also can be a powerful driver of the transitions illustrated in this chapter. The Food and Agriculture Organization’s Mitigation of Climate Change on Agriculture program documents many of these (www.fao.org).

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Policy innovation may emerge in unexpected contexts. For instance, the Law for the Orientation of Agriculture (LoA) became law in Mali in September 2006. In China the Circular Economy Law was adopted at the 4th Meeting of the Standing Committee of the 11th National People’s Congress on August 29, 2008. The Organic Law on Food Sovereignty received final presidential approval in Ecuador in May 2009. All three open up new spaces for the public at large and diverse interests to participate in the interpretation and implementation of the provisions. The LoA, Mali, asserts the principle of food sovereignty. It gives priority to the modernization of family farming, to the domestic and regional food and commodity trade, and to the social equity and environmental sustainability of technology choices and service provisions. The law evolved out of multi-stakeholder nationwide consultations, from village to national level. A series of citizens’ juries, culminating at the national level (February 2010), proposed and deliberated a series of options for how to translate the law into practice. The Circular Economy Law, China, “is formulated for the purposes of promoting the development of the circular economy, improving resource utilisation efficiency, protecting and improving the environment and realising sustainable development” (Art. 1). It sets out for every sector, including agriculture, forestry, and food, the generic measures required for “reducing, reusing and recycling activities conducted in the process of production, circulation and consumption” (Art. 2). Articles 10 and 11 give citizens the right to report “acts of wasting resources and damaging the environment,” “to propose their opinions and suggestions,” and “encourages agencies, societies and other social organisations to engage in the publicity, technical promotion and consultancy service of circular economy so as to promote the development of circular economy [sic].” The Food Sovereignty law, Ecuador, gives preference to the development of culturally appropriate food products and conversion to agroecological practices in farming and requires land to service its environmental and social functions (generating employment, distributing income equitably, conserving and utilizing biodiversity productively). The law institutionalizes a National Conference on Food Sovereignty with eight statutory members (including representatives for women, indigenous groups, and peasant movements), responsible for deliberating implementation, new proposals, research, and the merits of various options for translating the law into practice.

Conclusions Agroecology’s contribution to climate change mitigation and adaptation is no longer of purely theoretical interest. It has become a powerful organizing principle around which national and local government policy-makers, farmers, citizens, actors in commercial food chains, and scientists have begun to bring a more sustainable future into being. Many practical and scientific questions remain, but the outlines of transformational ways of thinking about and practicing farming and food systems under climate change are already being created.

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References Badege B, Neufeldt H, Mowo J, Abdelkadir A, Muriuki J, Dalte G, Assefa T, Guillozet K, Kassa H, Dawson IK, Luedeling E, Mbow C (2013) Farmers’ strategies for adapting to and mitigating climate variability and change through agroforestry in Ethiopia and Kenya. Oregon State University, Corvallis Garrity D (2009) Creating an evergreen agriculture in Africa. For food security and environmental resilience. World Agroforestry Centre, Nairobi Leakey R (2012) Living with the trees of life: towards the transformation of tropical agriculture. CABI, Wallingford Midega CA, Pittchar J, Salifu D, Pickett JA, Khan ZR (2013) Effects of mulching, N-fertilization and intercropping with Desmodium uncinatum on Striga hermonthica infestations in maize. Crop Prot 44:44–49 Renwick A, Mofakkarul Islam Md, Thomson S (2012) Power in agriculture: resources, economics and politics. A report prepared for the Oxford Farming Conference. The Oxford Farming Conference, Oxford Tesoriero AJ, Duff JH, Saad DA, Spahr NE, Wolock DM (2013) Vulnerability of streams to legacy nitrate sources. Environ Sci Technol 47(8):3623–3629 The Royal Society (2009) Reaping the benefits. The Royal Society, London Tomlinson I (2013) Doubling food production to feed the 9 billion: a critical perspective on a key discourse of food security in the UK. J Rural Stud 29:81–90

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Contents Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Socioeconomic Capabilities and Capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inequalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Crop Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Access to Food . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Food Consumption and Embodied Experiences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Keywords

Capacities and capabilities • Inequalities • Gender • Embodied experiences • Healthy bodies

Definitions Adaptation to climate change, as defined in the IPCC (2012, p. 556) special report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation, is understood as “the process of adjustment to actual or expected climate and its effects, in order to moderate harm or exploit beneficial opportunities.” Underlying adaptation is a set of capacities or capabilities, in the IPCC (2012, p. 556), defined as “the combination of the strengths, attributes, and resources available to an individual, community, society, or organization that can

P. Tschakert Department of Geography and the Earth and Environmental Systems Institute (EESI), Pennsylvania State University, University Park, PA, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_126, # Springer Science+Business Media Dordrecht 2014

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be used to prepare for and undertake actions to reduce adverse impacts, moderate harm, or exploit beneficial opportunities.” This capacity, as described by Eakin and Lemos (2006), is shaped by a set of determinants, including knowledge, income, health, risk perception, social mobilization, access to insurance and credit, regional planning, and risk-sharing mechanisms. Knowledge, just to use one example, includes the capacity to envision, discover, experiment, and innovate, and the ability to learn from mistakes, to gather experience of dealing with change, to adjust responses to both external and internal change processes, to anticipate the worst and plan ahead, and to transform when existing conditions become untenable (Tschakert and Dietrich 2010). Such a forward-looking capacity needs to actively engage not only with past and current hazards and stressors but also with fluctuating dynamics and unpredictable surprises, which further justifies flexible adaptive decision-making as a key ingredient for successful adaptation. However, as an abundance of case studies from around the world has demonstrated, many of which stem from community-level assessments in the global South, this capacity is socially differentiated. This means that it is unevenly distributed in society, reflecting social biases, differentiation, and discriminatory institutional practices that may facilitate timely, fair, and successful adaptive responses for some while undermining the same responses for many others. This chapter uses the perspective of intersecting dimensions of inequality and marginalization, along the axes of gender, race, class, caste, ethnicity, and (dis)ability, to reveal opportunities and barriers for food access and the role of emotional aspects in consumption and food security.

Socioeconomic Capabilities and Capacities The ability to juggle and negotiate uneven sets of capacities is what matters for people when attempting to balance their dynamic livelihoods while securing their food security. This ability determines who is entitled to grow which crops, who has the right and capacity to access food, either through household production, social networks, or the market, and who is allowed to consume which food (and water) and which quantities. Amartya Sen (1981) framed an understanding of food security through the now widely accepted concepts of capabilities and entitlements, although they are not free of critique. Sen’s focus on entitlements as commodity bundles shifted the perspective from insufficient food supplies to the inability of people to access food, despite sufficient availability. In his capability framework, Sen identifies political freedom, economic facilities, social opportunities, transparency guarantees, and protective security as the essential types of freedom that allow people to become agents of change and ensure their flourishing and improved quality of life. Martha Nussbaum’s (2000) basic capability set also entails human capabilities such as bodily health and integrity, control over one’s environment, and the right to determine one’s notion of a good life. La Via Campesina, an international peasant movement, takes this capability approach one step further

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by applying it to food sovereignty. The argument here is that people ought to have the right to define their own food systems and what constitutes healthy and culturally appropriate food that they produce, distribute, and consume. In the context of climate change, little is known to date how these capabilities, freedoms, and flourishing can be enhanced, and measured, through projects and programs on climate change adaptation. More research exists that explores the various factors that are likely to determine socioeconomic capabilities that facilitate adaptation as a socioeconomic and institutional process. These factors are often discussed as social capital, agency, vision, leadership, adaptive governance, and the role of institutions for providing access to information for better adaptation planning. Moreover, people’s identity, their values and worldviews, and power dynamics all facilitate or constrain adaptive capacities, and require ethical debates of how much risk and loss is acceptable in people’s livelihoods, and to whom. While there is growing interest in the various ways in which individuals, communities, and societal actors actively shape this very process, from both academics and practitioners, abundant evidence points toward obstacles that people encounter along the way. Poverty and inequality often undermine this potential for active engagement. Poverty typically means that people have few resources and capacities to fall back on in times of increased hardship. This includes little or no savings, and limited participation in reliable and reciprocal social networks. For lack of other options, people may opt for strategies that satisfy immediate livelihoods needs (often foodrelated) but erode critical assets over time. A substantial body of research now highlights one crucial factor among many that will allow or prevent people from securing sufficient, nutritious, and culturally important food under shifting climatic conditions and extreme climate events. This is the role of multiple dimensions of inequality and marginalization that shape people’s socioeconomic capabilities to adapt to climate change. A particular angle addresses embodied experiences of climatic conditions and, more specifically, access to food and the emotional implications of healthy and hungry bodies.

Inequalities Persistent, and, in some cases, new socioeconomic, political, and institutional inequalities that reflect structural conditions of development within and between countries, including those in high-income countries, hamper effective adaptation to climate change. Poverty and persistent inequalities, including gender inequalities, are the “most salient of the conditions that shape climate-related vulnerability” (Ribot 2010, p. 50). They determine opportunities and capacities in livelihood choices and trajectories. Complex interactions with weather events and climate change, combined with multidimensional poverty and deprivation as well as entrenched and new forms of inequalities, create an ever-shifting context of risk that remains difficult to measure and remedy. One way of approaching this complexity in understanding inequality and privilege as key drivers of adaptive capacity under climate change is to employ

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Education

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Religion

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Language Age

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Ability Income Aboriginality

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Fig. 86.1 Intersecting axes of identity and inequality (http://criaw-icref.ca/intersectionalgendered-analysis)

an intersectionality lens. This particular lens looks at various dimensions of inequality, marginalization, and privilege, and is attentive to particular contextspecific constellations in which gender, age, race, class, caste, ethnicity, and (dis) ability converge (see Fig. 86.1). Jointly, they assist or hinder capabilities and opportunities for effective and fair adaptation. Often, these dimensions of identity that shape inequalities are “mutually constitutive” (Shields 2008, p. 302), meaning that one category of identity, such as gender, can only be understood through its relation with another category, for instance, race. In the context of climate change and food security, such an intersectionality lens allows for examining which particular dimensions are relevant under which specific conditions and how they interact with each other, case by case. Instead of a priori assuming that women are more vulnerable to the negative impacts of climate change, an explicit attention to intersecting inequalities makes it possible to reveal, for instance, that women and girls from a low caste in Nepal (Dalit, the “untouchable” caste) are among the first to shift to drought-resistant buckwheat and to work more hours on the fields of their higher caste landlords while dropping out of school, thereby curtailing their own adaptive potential (Onta and Resurreccion 2011). In India, more women than men, especially women of lower castes, work as wage laborers to compensate for crop losses resultant from changing climatic conditions (Lambrou and Nelson 2013). Yet, class can play an important role too. In Tanzania, for instance, wealthier women hire poorer women to collect animal fodder during droughts, which enhances their own adaptive capacities and those of other community members (Muthoni and Wangui 2013). Similarly, such an intersectionality perspective would be beneficial to assess how responses to climate change affect particular people and their food security. Let us use the example of increasing biofuel production in many countries of the

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tropics, destined largely to reduce fossil-fuel dependence in highly industrialized states. So far, evidence points toward consequences such as land dispossession of smallholders, displaced food production, and displacement of people toward more marginal lands where both growing crops and adapting to climate change become more difficult (Cotula et al. 2009; Borras et al. 2011). How these policies affect the social-ecological capabilities of particular groups, especially women, ethnic minorities, and elderly farmers, is so far poorly understood (Julia and White 2012). Moreover, we find climate change mitigation and adaptation projects in the global South that offer ways to calculate and monitor household food-related carbon footprints, while growing consumption as part of expanding lifestyles in middleand high-income countries remains largely unchallenged. Carbon footprints in low-income countries are often related to women’s use of firewood for preparing food or their fertility rates and the number of hungry children to be fed. In other words, a simplistic north–south dichotomy in conceiving long-term climate solutions tempts us to draw preliminary conclusions about necessary adaptive strategies around food consumption that may perpetuate or even exacerbate existing inequalities.

Crop Production Marginalization and inequalities affect crop production, or more specifically who is able and allowed to engage in the cultivation of which particular crops and where. One insightful case study stems from Aymara farmers in the highlands of Bolivia who experience a dramatic retreat of the Mururata glacier compounded with a host of other environmental and social stressors (McDowell and Hess 2012). Pervasive poverty, the legacy of a major agrarian reform in the 1950s, continuous institutional racism and systemic discrimination against indigenous citizens, volatility in the agricultural market, bureaucratic hurdles in obtaining land titles and accessing bank loans, and lacking support for irrigation infrastructure and technical assistance, all undercut the socioeconomic capabilities of most Aymara farmers. At the same time, delayed seasonal rainfall, increased temperature, unpredictable frost, and more intense hailstorms threaten subsistence food production. Some few households have the financial resources to purchase herds of cattle and additional land at higher altitudes that are suitable for vegetables and fruit trees. The large majority of less endowed farmers, however, cannot afford to switch to income-generating livestock or high-labor crops and hence are less well-equipped to navigate changes in glacial meltwater. Moreover, extreme flooding events wash away precious farm land, further exacerbating land scarcity. Without any other viable options, those who have limited land to start with refrain from crop rotation and fallowing, which in turn contributes to the proliferation of pests on crops, not having resources either to buy pesticides. A second example, this time from rural Ghana, demonstrates how persistent gender inequalities can undermine adaptive response options to climate change and, consequently, put entire households at risk (Carr 2008). Although many women farmers would be eager to engage in market production in addition to subsistence cropping, men often tend to withhold access to additional lands that women could

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cultivate for market sale. This decision is not only to the personal detriment of women but to that of the entire household as it reduces household income and constrains real opportunities to face stresses and shocks that emerge from increasing climate variability. As a result, households survive at the level of barely sufficient material and food security. Carr’s explanation is that an outcome that also rewards women, spreads risks, and is more socially just would challenge a man’s authority and, thus, is perceived as unacceptable.

Access to Food Access to food is not only determined by the availability of crop land or financial resources to purchase food in times of climatic shocks. Not as much attention has been paid to informal social networks that often allow less well-endowed members of a community to access food based on their relationships with others. Two examples, one from Mozambique (Osbahr et al. 2008) and the other from Mexico (Buechler 2009), show how particularly women rely on reciprocal gifts to ensure additional food and labor and other crucial resources to sustain their households. In the case of Mozambique, the disproportionally high number of exchanges among female-headed households in the country’s moral economy is surprising: in only 1 year (2002/03), female-headed households engaged in a total of 12 exchanges, including reciprocal gifts of food and labor, to ensure their social safety net would remain intact. This is compared to a total of 10 in male-headed households and much larger households. More important still, giving gifts in these female-led households accounted for almost twice as many interactions, while other households had an approximate equal balance between giving and receiving. Women’s ability to reciprocate, however, drops significantly during times of crises, as it does for the elderly, as gifts of food, small livestock, or cash and labor, on which their social networks rely, become harder and harder to produce. This makes female-headed households and the elderly in rural Mozambique particularly vulnerable as it undermines their capabilities to adapt. In the case of Sonora, Mexico, climate change has shifted the range of vegetables and fruit trees that can be sustained. Plum and apricot production, for instance, is no longer possible as most of the trees have disappeared due to increased temperatures. Losses from canned fruit and pickled vegetable production do not only lower available food for household consumption and incomes for women in charge of the processing they also reduce their own adaptive potential as well as that of the entire community as less jars of jelly as reciprocal gifts weaken important social ties that function as safety nets within and between households and across the border with the USA. Despite numerous examples from rural communities, access to food is also crucial to urban consumers. Many disadvantaged people in urban areas, particularly wage laborers, tend to erode their financial capital when food prices increase. The reason is that most urban and wage-labor dependent households use a large income share to purchase staple crops. Spikes in food prices in 2007–8 and then again in

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2011 triggered food demonstrations and riots across all continents, partially fueled by droughts in major producer areas, and the conversion of cropland for biofuel production, but also by persistent inequalities and governance failure in increasingly urbanized regions. It remains challenging, however, to predict the impacts of future climate change on food access. While there is evidence to presume that poverty headcounts will drop in most low- and middle-income countries before mid-century, most African countries are likely to experience yield impacts too severe to allow benefits (Hertel and Rosch 2010). Also, given the continued increase in the number of urban poor, especially wage laborers, it needs to be expected that a large number of these urban residents will shift from a transient to a chronic state of poverty, primarily due to exposure to food price increases. This is particularly true under scenarios with long-duration climatic shifts and prolonged droughts (Ahmed et al. 2009).

Food Consumption and Embodied Experiences This last section explores food consumption, not so much as a caloric accounting but as an embodied experience of climatic changes. Unlike dominant emphasis on agrofood systems and technological innovation to enhance crop yields and withstand extreme weather shocks, the perspective of embodied experiences pays explicit attention to everyday practices of food consumption and this at less visible scales, typically the individual and the body. Who precisely gets to eat, what, and how much? Answers to these questions are tightly linked to the multiple dimensions of inequality and marginalization, discussed above, at the intersection of class, race, gender, ethnicity, age, caste, and (dis)ability. Incremental climate change, climate variability, and extreme events that result in floods, droughts, and heat waves already amplify food shortages. In several documented cases, for instance, the 2007 Ugandan floods, mostly women and children forwent meals, medicines, and school fees, all of which lower their human capital and socioeconomic capabilities to adapt; poor people in general tended to sell their physical and natural assets, such as livestock, at very low prices, thereby undermining their future response capacities (Renton 2009). The fact that female bodies consume less food has also been observed in India (Lambrou and Nelson 2013), making women often more susceptible to diseases. One way of approaching embodied experiences is through explicit attention to the (in-)visibility of “small things” in everyday practices. This perspective requires a re-consideration of what we as scholars or practitioners count as evidence in climate change studies and accounts. In contrast to changes in yields of major staple crops such as rice, wheat, and maize, which are visible, easily countable, and captured in national and internationals statistics, above all by the Food and Agricultural Organization (FAO), embodied experiences occur at small scales. Not surprisingly, examples like the reduced exchange of jelly jars and consequences for social networks among women and entire communities in Sonora, Mexico, are often missed when considering opportunities and barriers for adaptation. \Many of these embodied experiences are simply difficult to measure. They may

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even evolve emotions such as fear, loss, and anger that, unfortunately, are easily disregarded as subjective and hence will likely not be counted as soundproof for climate change impacts or as motivation for the adoption of certain adaptive strategies. Yet, increasing evidence from embodied experiences of changes in landscapes of everyday life or daily practices of fetching water allows us to visualize what corporeal dimensions there must be to food, food consumption, and healthy and hungry bodies. For instance, accounts of water and sanitation practices in Delhi’s slums convey the “everydayness” of water (Truelove 2011). The daily practices in which women engage go straight through their bodies: walking long distances in search of culturally appropriate and safe sanitation spots, procuring water from illegal sources that risk triggering physical abuse and criminalization, or becoming ill from contaminated water. In analogy, one can envision the embodied experiences of disadvantaged populations while attempting to secure food under increasing climate volatility. Subsequent food consumption may result in so far underexplored forms of corporeal vulnerability that further undermine adaptive capabilities. These forms are yet to be included in climate impact statistics.

Conclusion Food security under climatic stress cannot be guaranteed without addressing structural and often deep-rooted inequalities that transcend societies both in the global North and South. Lessons learned from monitoring and evaluating adaptation programs show that approaches that fail to consider the multiple drivers of social inequalities, especially gender inequality, risk reinforcing existing vulnerabilities. More attention ought to be paid to whether interventions to increase yields in rural economies benefit men over women or more endowed households over poorer families. Equal attention needs to be paid to whether proposed adaptation initiatives that preserve seed stocks or water reservoirs increase labor demands on particular groups that they can ill afford, especially without undermining their own adaptive potentials. A better understanding of intersecting dimensions of privilege and marginalization would allow pinpointing maladaptive strategies before they are undertaken. Finally, rights-based approaches to food access and food sovereignty can inform sustainable and fair adaptation efforts. At the core are commitments to understand and remedy the ways in which institutional practices shape access to resources and control over decision-making processes and, most importantly, a commitment to flourishing and well-being for all.

References Ahmed SA, Diffenbaugh NS, Hertel TW (2009) Climate volatility deepens poverty vulnerability in developing countries. Environ Res Lett 4(3):034004 Borras SM Jr, Hall R, Scoones I, White B, Wolford W (2011) Towards a better understanding of global land grabbing: an editorial introduction. J Peasant Stud 38(2):209–216

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Buechler S (2009) Gender, water, and climate change in Sonora, Mexico: implications for policies and programmes on agricultural income-generation. Gender Develop 17(1):51–66 Carr ER (2008) Between structure and agency: livelihoods and adaptation in Ghana’s Central Region. Glob Environ Chang 18(4):689–699 Cotula L, Vermeulen S, Leonard R, Keeley J (2009) Land grab or development opportunity? Agricultural investment and international land deals in Africa. International Institute for Environment and Development (IIED), London, pp 1–145 Eakin H, Lemos MC (2006) Adaptation and the state: Latin America and the challenges of capacity building under globalization. Glob Environ Chang 16:7–18 Hertel TW, Rosch SD (2010) Climate change, agriculture, and poverty. Appl Econom Perspect Policy 32(3):355–385 IPCC (2012) Glossary of terms. In: Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation [Field, C.B., V. Barros, T.F. Stocker, D. Qin, D.J. Dokken, K.L. Ebi, M.D. Mastrandrea, K.J. Mach, G.-K. Plattner, S.K. Allen, M. Tignor, and P.M. Midgley (eds.)]. A Special Report of Working Groups I and II of the Intergovernmental Panel on Climate Change (IPCC). Cambridge University Press, Cambridge, UK, and New York, NY, USA, pp. 555–564 Julia, White B (2012) Gendered experiences of dispossession: oil palm expansion in a Dayak Hibun community in West Kalimantan. J Peasant Stud 39(3–4):995–1016 Lambrou Y, Nelson S (2013) Gender issues in climate change adaptation: farmers’ food security in Andhra Pradesh. In: Research, action and policy: addressing the gendered impacts of climate change. Springer, New York, pp 189–206 McDowell J, Hess J (2012) Accessing adaptation: multiple stressors on livelihoods in the Bolivian highlands under a changing climate. Glob Environ Chang 22(2):342–352 Muthoni JW, Wangui EE (2013) Women and climate change: strategies for adaptive capacity in Mwanga District, Tanzania. African Geographical Rev 32(1):59–71 Nussbaum M (2000) Women’s capabilities and social justice. J Human Develop 1(2):219–247 Onta N, Resurreccion BP (2011) The role of gender and caste in climate adaptation strategies in Nepal. Mountain Res Develop 31(4):351–356 Osbahr H, Twyman C, Neil Adger W, Thomas DSG (2008) Effective livelihood adaptation to climate change disturbance: scale dimensions of practice in Mozambique. Geoforum 39(6):1951–1964 Renton A (2009) Suffering the science: climate change, people, and poverty. Oxfam International, Boston, pp 1–61 Ribot J (2010) Vulnerability does not fall from the sky: toward multiscale, pro-poor climate policy. In: Mearns R, Norton A (eds) Social dimensions of climate change: equity and vulnerability in a warming world. The World Bank, Washington DC, pp 47–74 Sen A (1981) Poverty and famines: an essay on entitlement and deprivation. Clarendon, Oxford Shields A (2008) Gender: an intersectionality perspective. Sex Roles 59:301–311 Truelove Y (2011) (Re-)conceptualizing water inequality in Delhi, India through a Feminist Political Ecology framework. Geoforum 42(2):143–152 Tschakert P, Dietrich KA (2010) Anticipatory learning for climate change adaptation and resilience. Ecology and Society 15(2):11, www.ecologyandsociety.org/vol15/iss2/art11/

Part IX Greenhouse Gases and Geoengineering Ben Kravitz

The Strategic Value of Geoengineering Research

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Jane C. S. Long and John G. Shepherd

Contents Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Geoengineering Research is Frankenstein’s Academy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A Strategic Approach to the Climate Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Geoengineering and Climate Science . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

Deployment of geoengineering technology should engender serious caution, but geoengineering research would engender a strategic effect on the climate change problem in general. First, the thought that scientists should research geongineering because the world might need it could help society develop an appreciation of the seriousness of the climate change problem. Second, conceptualizing geoengineering through research promotes conceptualizing a sorely needed technical strategy for climate change. Finally, geoengineering research will have a strategic benefit for climate science because the scientific issues that arise for geoengineering bring into focus the very issues that plague climate science in general.

J.C.S. Long (*) Bipartisan Policy Center and the Environmental Defense Fund, Oakland, CA, USA e-mail: [email protected] J.G. Shepherd University of Southampton, Southampton, UK e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_24, # Springer Science+Business Media Dordrecht 2014

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Keywords

Carbon dioxide removal • Climate change • Climate engineering • Climate science • Climate strategy • Geoengineering • Solar radiation management

Definitions Geoengineering (or Climate Engineering): the intentional modification of the climate Solar Radiation Management (SRM): a method changing the climate by adjusting the radiative balance of the Earth Carbon Dioxide Removal (CDR): a method of lowering the atmospheric concentration of CO2 Intertropical Convergence Zone (ITCZ): the area encircling the earth near the equator where the northeast and southeast trade winds come together Intergovernmental Panel on Climate Change (IPCC): The IPCC is a scientific body under the auspices of the United Nations (UN) which reviews and assesses the most recent scientific, technical and socio-economic information produced worldwide relevant to the understanding of climate change.

Introduction Society faces serious difficulties in solving the problem of climate change. People have emitted over 1,000 billion tons of CO2 in the last 100 years. Even if all emissions were stopped today, some of these prior emissions would remain for 1,000 years or more and continue to warm the planet. These emissions have created a risk that is effectively permanent. The situation continues to get worse. It has proven very difficult to reduce (“mitigate”) these emissions. The more greenhouse gases emitted, the more the planet will warm and the higher the risk of dangerous climate change. How much the climate will change as a result of past and future emissions is not yet known precisely. However, it now looks highly probable that during this century, the concentration of CO2 in the atmosphere will more than double that in the preindustrial era, and our world will warm by several degrees C. The complexities of the Earth System mean that there are still fairly large uncertainties (around 50 %) in our estimates of how much the climate will change for any given amount of greenhouse gases in the atmosphere. The basic phyiscs of global warming has been well understood for over a 100 years: we know that more greenhouse gases trap heat in the atmosphere and warm the Earth. Scientists can not predict precising how fast this will happen, by how much, and (especially) with what variation around the globe. Ocean dynamics; feedbacks due to clouds, aerosols, snow, and ice cover; and the carbon cycle modulate and complicate the climate response. But climate science is quite accurate enough to tell us that the risk of dangerous climate change is significant and increasing all the time.

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The increasing probability of climate impacts includes severe droughts, floods, heat waves, rising sea level, and extreme storms. There is also an increasing threat of more rapid climate change resulting from positive climate feedbacks. For example, increasing temperatures in the Arctic could thaw the permafrost where about 1,700 billion tons of organic carbon are held, distributed over 8.8 million square kilometers which could be released as either CO2 or methane (Tarnocai et al. 2009). That is over four times more than all the carbon emitted by human activity in modern times and about twice as much as is present in the atmosphere now, since one ton of carbon equates to 3.67 t of CO2. If even a relatively small amount of the carbon locked in the tundra is released in the form of methane each year, the greenhouse gases would result in more rapid warming which would in turn release more greenhouse gases. Schaeffer et al. have projected that within decades the Arctic permafrost may switch from being a carbon sink to a carbon source (Schaeffer et al. 2011). If this happens, then within a few more decades, temperatures could begin to increase even faster. It would be sensible to avoid as much of the risk of climate change as possible. Thus, avoidance and mitigation (defined as actions taken to stop emitting greenhouse gases) are necessary and in many ways the best strategy (prevention is the best medicine). If society could stop emitting greenhouse gases, we would stop increasing the risk of dangerous climate change. However, the world has not even begun to slow down the growth of emissions – which continue to increase even in this time of economic stress – much less reduce them or stop them altogether. Tragically, the world has had a problem agreeing on how much action is necessary. In principle, it would be technically possible to reduce emissions greatly by the midcentury. For example, a recent study in California found that we already have the technology required to reduce emissions and still accommodate population and economic growth (California’s Energy Future, the View to 2050, 2011). This study estimated that an all-out effort to eliminate burning of fossil fuel through radical increases in efficiency, massive electrification of transportation and heating, the total conversion of electric generation over to a system that did not produce emissions, and the use of all possible sustainable biomass for biofuel would reduce emissions by 60 % by 2050, and it might be possible to reduce emissions by 80 % with significant innovation in the energy sector. Similar studies in Europe have reached similar conclusions, but such a concerted effort seems unlikely at this time. Nevertheless, it will be important to eliminate the emission of greenhouse gases as soon as possible. Put something here about land use emissions. . .. Mitigation may be our primary response for combating climate change, but another necessary response will be to adapt to unavoidable change. Some impacts of climate change are now inevitable. Sea level will rise as the water warms and expands and polar ice-sheets melt, and this will inundate highly populated coastal regions. Heat waves will become more frequent accompanied by droughts and fires. Extreme and untimely weather will result in more frequent and larger-scale flooding. Society can respond by resisting these changes (building higher dikes, fighting more fires) or by becoming more resilient to the changes, (building floating houses that are

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not damaged by floods or doing a better job managing the water supply) or people may have to retreat from regions that become uninhabitable in the new climate regime. Communities already face unavoidable choices to resist, become resilient to or retreat from the impacts of climate change. Conditions will simply become more difficult and more extreme with the new stress of a warming world. Factors may combine, and their effects may multiply. For example, the UN estimates there will be as many as 10 billion people by the end of the century (UN 2011). So, at the same time that societies need to decarbonize the energy system, revise agricultural practice to stop the emission of the powerful greenhouse gas, nitrous oxide, and save forests to act as carbon sinks, they will also need to double our food and water supplies. Two billion people are already without adequate water, with four billion more such people expected in just a few decades, and at the same time more frequent and extreme droughts may occur. Part of the difficulty will be an inability to predict the Earth’s behavior in detail and therefore a consequent inability to plan for the needs of the world’s population. At some point, these changes may become very difficult to handle, and circumstances may occur that would result in great suffering, especially for the world’s most vulnerable people. It is this set of possible dire circumstances that have brought a number of scientists to the conclusion that society should investigate a set of methods that would directly and intentionally aim to reduce climate change, that is, geoengineering. Two types of geoengineering methods are commonly discussed: those that reduce the amount of sunlight heating the Earth (solar radiation management, SRM) and those that remove the greenhouse gases from the atmosphere (carbon dioxide removal, CDR) as described by the Royal Society (2009). In addition, the American Meteorological Society (2009) has identified some possible approaches that are not strictly in either of these categories. This last category recognizes that not all ideas have yet been explored and that the lines between mitigation, adaptation, and geoengineering could become blurred. Extreme adaptation to major regional impacts of climate change may not really look significantly different from “geoengineering” as normally defined. For example, to stop Arctic sea-ice from melting might motivate some focused solar radiation management. A recent report sponsored by the National Commission on Energy policy made recommendations to the US government for commencing geoengineering research along these lines (2011). We may never know enough to do SRM climate engineering with high confidence in the outcome, but if the world faces a situation that demands urgent action, some governments may nevertheless wish to choose this path. We cannot rule out events that could lead to a geoengineering choice, so proceeding in the current state of ignorance would not be prudent. Geoengineering in general and SRM methods in particular are in a very early stage of research. What might be effective, possible, affordable, and advisable? Many of the ideas circulating the scientific community such as cloud brightening, injecting aerosols in the stratosphere, or fertilizing the ocean may prove to be ineffective, impractical, or inadvisable. The more we think about it soon and the more people that are thinking about it, the more likely we are to identify ideas that may

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be useful and safe and even more importantly, to rule out ideas that would not be safe or effective. Perhaps the worst possible outcome would be for the world to be in climate extremis and then, in desperation, for some country to decide to deploy SRM geoengineering without having done due diligence on the advisability of such actions, for themselves and for other people (Blackstock and Long 2010). So, the methods and ideas require research, but the outcomes of this research could have existential impacts and intimidating ethical, political, scientific, and technical implications. Because the concept of geoengineering, particularly SRM, is so worrisome and because the very idea is inherently strategic in nature, research in this area could however provide a focus for developing both scientific and societal skills in dealing with climate change. We argue here that the special nature of geoengineering research could also have three beneficial, strategic nontechnical consequences for the climate problem: 1. Because intentional modification of the climate is horrifying to many people, it could help them to focus on the climate change problem with more urgency. 2. Geoengineering research could help to establish a clearer appreciation of the magnitude of the climate change problem and promote a strategic approach to it. 3. Geoengineering research is likely to further motivate climate scientists to focus on the most important unknowns in the climate system. Each of these strategic aspects of geoengineering research is discussed below.

Geoengineering Research is Frankenstein’s Academy The idea of intentionally trying to engineer the climate seems like something from a sci-fi horror movie. The script runs thus: “Evil technocrats try to bend the climate to their will, careless of the consequences. Then, a heroic (but ordinary) person finds a way to stop the evildoers and the Earth is saved.” The problem here is that the story line is completely wrong. Ordinary humans are the cause of the dangerously changing climate, and there has been no evil plot. The global changes have not been made intentionally: they have been inadvertent by-products of industry and improvements to our quality of life. Could heroic scientists actually save us by modifying the climate of the Earth? If so, it may not be evil deeds that people have to worry about. It may be incompetence and the hubris to think that mankind could manage complexities they cannot fully understand. Intention matters. It is the difference between murder and manslaughter. In the UK, survey results found that people felt that climate change due to energy use was “regrettable” while the concept of geoengineering was simply “horrible” (Orr et al. 2011). Even though unintentional climate forcing is likely to be far more extensive and damaging than that likely for a geoengineering intervention, it is the intentionality that makes geoengineering so problematic. Our continued emission of greenhouse gases is usually regarded as “unintentional” but is already dangerously transforming the planet that is our only home. In fact, one can argue that since mankind now knows that we are causing climate change, it is really no longer credible to say that what we do is

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“unintentional.” Doing nothing is the result of a decision not to act. Since we understand the dangers, we now have a moral imperative to act responsibly for the state of the environment that we shall leave to future generations. Past intentional attempts to manipulate our environment have often failed, especially when biological systems are involved. These are complex systems, layered, subtle and highly interconnected, and not always as resilient as would be desirable. The idea that humans could actually design and implement an effective and safe global intervention seems optimistic. The interventions will surely interact with other Earth systems that are critical for sustainable life, including freshwater, soil, oceans, ozone, food, ecosystems, and human migration. Geoengineering (SRM especially) will involve technical, economic, ecological, environmental, social, political, and even cultural problems. For good reasons, most people do not really trust humans to do this yet (or maybe ever). Society should certainly be wary of intentional intervention in the climate. Many of the climate engineering ideas being contemplated, such as injecting reflective particles into the stratosphere, may lead to unexpected or unintended results. Deployment of these techniques could probably lower the Earth’s temperature, but this is not the same as returning the climate to a prior “safe” state. The deployment of such SRM technologies could adjust rainfall patterns, ecosystems, economic and cultural systems, and agricultural productivity back towards a previous state, but the “cancellation” would hardly be perfect. Some aspects would probably be under-compensated and others overcompensated (Ricke et al. 2010). That would create novel climates, i.e., not on the past trajectory of greenhouse-induced climate change. Thus, even though such technology could help reduce climate impacts for some or perhaps most of the planet, some parts of the planet may not be affected positively or may even experience worse impacts. SRM geoengineering could benefit some (possibly most) people in most places but might also unintentionally harm the livelihoods of others in other places. It will be impossible to predict with great precision the outcomes of such intentional intervention in the climate. To some extent, the implementers would be flying with only rough and ready navigation. This “horrible” idea of intentional climate intervention goes hand in hand with the requirement for taking responsibility for our climate and accepting that mankind now has stewardship of the planetary environment. Geoengineering creates a tension between the hubris of thinking that humans could manage the problem and the responsibility to try. If climate change goes as far and as fast as now seems likely, the risks of not attempting to intervene may exceed the risks of trying to do so. If prudence dictates the need to know more about geoengineering and society begins to discuss and research ideas for geoengineering, this exploration could in fact help humanity to develop the understanding and skill needed to manage climate change. Just to contemplate geoengineering is to recognize that the world has a serious problem. For many years, environmentalists did not want to bring adaptation to climate change into discussion, because, if humans fail to

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mitigate greenhouse gas emissions, climate change will become even more rapid and damaging and so even more difficult to adapt to. So, activists were reluctant to encourage people to consider how they could adapt to climate change, because they might begin to think that they could just adapt, and would not need to do the hard work of mitigation. Public discussion about adaptation was considered to create a “moral hazard.” Now, most people realize that they shall have to adapt to climate change. More forward-thinking cities and states are preparing plans for dealing with rising seas, bigger storms, more droughts, and severe heat waves. It turns out that planning for adaptation does not actually make people feel that mitigation is unnecessary. To the contrary, it can make people think that they would prefer to avoid the costs and problems that adaptation involves (http://onlinelibrary.wiley.com/doi/10.1111/j.15396924.2008.01049.x/full). Many commentators have pointed out that public discussion of geoengineering may create a similar moral hazard in that it could also distract us from the important work of mitigation. But, the characteristic “horror” of geoengineering could also serve to communicate just how worried climate scientists are about our future and so motivate a renewed commitment to mitigation. Surveys show that this may in fact be the case (Kahan et al. 2012). Another aspect of geoengineering research is the need to develop public engagement and oversight of any activities that aim to modify the environment. Geoengineering research should start with modeling studies and field experiments that pose zero or negligible environmental or ecological risk. Such research will not look much different from climate research. But, at some point the engineering aspects of delivery will become important, and learning more will require making larger and more invasive experiments. Since the whole idea of geoengineering deployment is potentially dangerous and the research itself may become dangerous over time, the interests of society will have to be integrated into research decisions. Society will have to play a role in governing this research. Because the problem and potential solutions are inherently international, we consider that research should also be developed as an international effort. Developing the societal skills and techniques required to govern geoengineering research could be a gradual process, through learning by doing rather than trying to foresee and solve all the difficulties at the outset. Contemplating geoengineering forces us to consider climate change objectives, choices for meeting such objectives, ways to choose among choices, and ways to manage those choices that have been made. Those investigating geoengineering will have to find a way to share information and jointly decide on strategy, agree on appropriate goals of the research, decide on research options, monitor the results, and make decisions about what to do next. This would all be very good practice for dealing with the problems of climate change in general, free of the immediate socioeconomic impacts that make climate choices so hard. If the world ever takes a decision to deploy geoengineering (particularly SRM), the intervention is likely to overlay one unnatural state on another. This is quite different from the “going back to nature” that some CDR techniques may

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approximate. SRM geoengineering is more like a renovation process for the Earth: like renovating an old house that has rotten windows, holes in the roof, and a broken furnace. You might never be able to restore it to a former state, but you can probably renovate it to a habitable state. Geoengineering is analogous to “renovation” to a designed future state. So, engaging in geoengineering research means there has to be dialogue and public engagement about societal values and preferences for the state of the climate. The institutions and processes needed to manage this problem are virtually nonexistent (Walker et al. 2009) at this point in time. Perhaps the effort to conduct and manage geoengineering research will help to support or even build the institutions required to deal with societal and environmental problems more generally. Society will struggle with the management of geoengineering research, and that struggle is likely to be a good practice for the climate problem in general. The institutions managing geoengineering research will have to make decisions about whether or not to allow research that may itself pose some risk, and those decisions will need to evolve over time. At first, they will only have to deal with the relatively easy problem of what very low-risk research should be allowed to continue without much specific oversight on a project-by-project basis, such as modeling studies or laboratory investigations. But over time, as research warrants outdoor experiments, the problem of the research itself posing non-negligible risks will have to be faced. It will be important for the institutions concerned to estimate and evaluate the social risks as well as the physical risks. They will need to consider such questions as who is doing the experiment? Who is paying? What is the intention? Just by delineating allowed research society will start to learn how to govern. How should the public be consulted? How should advisory or review boards be involved? Who has authority? How will transparency be ensured? What are the protections against vested interests having too much sway over decisions? What are the responsibilities of scientists to society? What is the role of the international community? It is possible that grappling with these questions in relation to a research program will help us to learn the skills for making good decisions in relation to stewardship of the climate and the environment in general. Geoengineering is a scary and maybe horrifying idea, but it just might become necessary. Between the horrifying and the necessary, there may be room to grow as a society.

A Strategic Approach to the Climate Problem Deciding whether or not to use geoengineering would require us to make strategic choices about the future of our climate. Geoengineering strategies (assuming that these options can indeed be developed and deployed) could contribute along with the primary strategy of mitigation, and the unavoidable process of adaptation, to reducing the suffering caused by the impacts of climate change. It will be very difficult, and may be impossible, to design or even to define an optimal

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Fig. 87.1 A strategic approach to a portfolio of responses to climate change. Note: the line for impacts and suffering, after these have been reduced by adaptation, is drawn hatched, since these cannot be located on a simple temperature scale. The intention is to show the level of impacts and suffering that would correspond to a lesser degree of warming, without adaptation, for comparison

strategy for dealing with climate change. But, if people contemplate how geoengineering might best be used, it may help us to think strategically about how humans might manage the climate (since that is what we are now doing, whether we like it or not). High-leverage SRM methods could take effect quickly but would create an “artificial, approximate, and potentially delicate balance between increased greenhouse gas concentrations and reduced solar radiation, which would have to be maintained, potentially for many centuries.” Conversely, CDR methods operate only very slowly but address the root cause of the problem. They return the climate system to a state much closer to its natural state, albeit slowly and do so, in effect, permanently (ibid). Rather than considering climate technologies such as SRM as a long-term alternative to climate mitigation, one intriguing possibility would be to implement SRM methods for a limited period of time, to achieve a rapid response, if it were determined that something must be done to quickly reduce dangerous temperature increases (Wigley 2006). Then it might also be possible, and would be prudent, to commence the use of CDR techniques at the same time, with the aim of decreasing atmospheric levels of CO2 as rapidly as possible to the point where there is no longer a need for the SRM intervention. So, CDR could provide an exit strategy for SRM and would thus avoid the “termination problem,” i.e., the potential for a rapid rise in temperature and resulting large climate shock if an SRM intervention were to be suddenly discontinued (Royal Society 2009; Robock et al. 2008). Figure 87.1 illustrates a conceptual strategy. Its purpose is not to promote any specific course of action, but to illustrate in a strategic and holistic way how various actions might interact to affect the outcomes. If society begins serious mitigation now, we may yet avoid some (but not all) of the expected temperature increase from a business-as-usual scenario (thus capturing the top “slice” of reduced impacts by emissions reductions). When emissions have been eliminated (or at least reduced to some low but intractable level), both atmospheric CO2 concentrations and warming will peak and remain roughly constant for a long time thereafter.

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The mitigation strategy is critical but is now very likely to be insufficient to prevent global average temperatures from rising to dangerous levels. To reduce the impacts of warming (and the other climate changes associated with it), SRM might be deployed for a limited time to control temperatures, while CDR is also implemented to slowly reduce atmospheric greenhouse gas concentrations again, to below the level that could be achieved by mitigation measures alone. Even with mitigation and geoengineering, the climate will still have changed, and people will have to adapt to the remaining impacts of this climate change. The impacts that cannot be reasonably addressed by adaptation will cause suffering. All of these options bear costs, either costs of implementing them or losses incurred by failing to do so. People shall have to choose what mix of actions and inactions we prefer in our portfolio of responses.

Geoengineering and Climate Science The science of climate change now incorporates an adequate understanding of the major driving forces and their likely effects (IPCC (2007a, b) (see also Royal Society 2011 for a short overview). But climate science cannot now, and may never be able to provide a precise prediction of future climate states and how quickly they will evolve. Nevertheless, scientists should constantly strive to improve the precision of predictions and compare them frankly and transparently with observations over time. There is likely to be synergy between this quest and geoengineering research. In order to understand how humans might intentionally change the climate, we must also understand what is likely to happen if we do not intervene. So geoengineering research can provide additional stimulus for trying to understand how the climate works and how our unintentional interventions are likely to play out. This is likely to be only a minor additional focus for an already large research agenda. However, the geoengineering focus is likely to provide a much clearer priority for resolving climate issues that can have large impacts. One of the most ironic aspects of geoengineering as currently conceived is that the two most promising ideas for SRM are to inject aerosols in the atmosphere and to brighten clouds, both in an effort to reflect solar radiation and to cool the Earth. At the same time, two of the largest factors contributing to uncertainty in climate predictions are the role of aerosols and clouds (Walker et al. 2009), which can both reflect and absorb radiation. Both are very complex and difficult to characterize, because their roles in the climate system vary with time and space. Yet these two components of the Earth system also hold the potential of significant leverage in managing a difficult climate problem. The well-known estimates of climate forcings found in the IPCC reports (Fig. 87.2) illustrate this. The error bars on the radiative forcing from aerosol/cloud albedo effects approach half of the size of the actual forcing from CO2 itself. Geoengineering research which aims to illuminate the effects of intentional injection of aerosols in the atmosphere, or methods for brightening clouds, is likely

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Fig. 87.2 The figure shows global mean radiative forcings (RFs) grouped by agent type. Anthropogenic RFs and the natural direct solar RF are shown. Note large standard deviations in the negative forcings possible from aerosols and clouds (After Fig. 2.20 in IPCC (2007b)

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to include controlled experiments where researchers vary the amount and type of particles injected into the atmosphere and measure the resulting changes in important climate factors such as albedo. Consequently, experiments and investigations conducted for geoengineering research will also provide critical information about how these same processes affect climate in the first place. Another important impact on climate research could come from geoengineering concepts inspired by the desire of society to ameliorate specific climate impacts. MacCracken (2009) suggests the possibility of moderating tropical cyclones, shifting storm tracks to prevent drought, stopping the melting of the Arctic and mountain glacier ice, offsetting reductions in air pollution as society begins to clean up coal-fired plants, etc. He reviews a number of possible approaches to each of these, which might include localized cloud brightening or regional aerosol loading, using bubbles to brighten the sea surface, or using wind power to mix surface waters of the oceans. Localized interventions would deliberately cause changes on the scale of weather systems, and these are even more difficult to understand than global-scale interventions. They would demand an ability to predict features like clouds and precipitation on scales that are not yet adequately represented in climate models, and they should, like large-scale geoengineering, still be approached with great caution. However, the effort to understand regional interventions will have a concurrent impact on improving the scientific information about clouds, aerosols, and ocean/atmosphere interactions for climate models in general. A final example is the problem of permafrost melting. There are major questions about how much carbon could be released, how fast, and in what form (whether oxidized as CO2 or “raw” as CH4). Up to now there has been relative little work on this problem. A focus on geoengineering would force scientists to address some very serious questions: What would constitute a tipping point from which there was no turning back? How would scientists know the climate is approaching such a tipping point? What would it take to avoid this tipping point? Could people intervene (beyond mitigation), and if so, how could we prevent the Arctic system from passing into a strongly emitting phase? Would it be acceptably safe to intervene in the Arctic but not also the Antarctic? Would that affect the location of the Intertropical Convergence Zone (ITCZ) and thus modify monsoon systems? If scientists think about geoengineering the Arctic to prevent massive releases of carbon, they will necessarily be asking research questions with great relevance to climate science and to society.

Conclusions Geoengineering research will be a challenge. The science and engineering will be at least as challenging as climate science and technology development for mitigation and adaptation. The social aspects of the research will require institutional management unlike any attempted in the past. This research may or may not result in any practically realizable technology to combat climate impacts. However, undertaking this research is likely to help people to deal with the climate problem in general, enhancing not only our comprehension of the problem, but also how we

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think strategically about solving it, and making sure that critical climate science issues are identified as a focus for research. This could be the silver lining of what seems otherwise to be a cloud-obscured and rocky path towards an uncertain future.

References American Meteorological Society (2009) Geoengineering the climate system: a policy statement of the American Meteorological Society. http://www.ametsoc.org/policy/2009geoengineeringclimate_amsstatement.html Blackstock J, Long JCS (2010) The politics of geoengineering, January 2010, Science 29 327(5965):527. http://www.sciencemag.org/content/327/5965/527 California’s Energy Future, the View to 2050 (2011) California Council on Science and Technology. http://www.ccst.us/publications/2011/2011energy.pdf Geoengineering: A National Strategic Plan for Research on the Potential Effectiveness, Feasibility, and Consequences of Climate Remediation Technologies (2011) Bipartisan Policy Center, Washington, DC http://www.bipartisanpolicy.org/sites/default/files/BPC%20Climate% 20Remediation%20Final%20Report.pdf http://onlinelibrary.wiley.com/doi/10.1111/j.1539-6924.2008.01049.x/full for example IPCC (2007a) In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate change 2007: the Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK/New York IPCC (2007b) Forster P, Ramaswamy V, Artaxo P, Berntsen T, Betts R, Fahey DW, Haywood J, Lean J, Lowe DC, Myhre G, Nganga J, Prinn R, Raga G, Schulz M, Van Dorland R 2007: Changes in atmospheric constituents and in radiative forcing. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate change 2007: the Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK/New York Kahan DM, Jenkins-Smith HC, Tarantola T, Silva CL, Braman D (2012) Geoengineering and the science communication environment: a cross-cultural experiment (9 Jan 2012). The Cultural Cognition Project Working Paper No. 92. Available at SSRN: http://ssrn.com/ abstract¼1981907 or http://dx.doi.org/10.2139/ssrn.1981907 MacCracken MC (2009) On the possible use of geoengineering to moderate specific climate change impacts. Environ Res Lett 4:045107 (14 pp) Orr PR, Twigger-Ross CL, Kashefi E, Rathouse K, Haigh JD (2011) Evaluation of ‘experiment earth?’ Public dialogue on geoengineering. A report to the Natural Environment Research Council (NERC) Collingwood Environmental Planning Ltd, London Ricke KL, Morgan MG, Allen MR (2010) Regional climate response to solar-radiation management. Nat Geosci. doi:10.1038/ngeo915 Robock A, Oman L, Stenchikov G (2008) Regional climate responses to geoengineering with tropical and Arctic SO2 injections. J Geophys Res 113, D16101. doi:10.1029/2008JD010050 Royal Society (2009) Geoengineering the climate: science, governance and uncertainty, John Shepherd chair. http://royalsociety.org/uploadedFiles/Royal_Society_Content/policy/publications/2009/8693.pdf Royal Society (2011) Solar radiation management: the governance of research. http://royalsociety. org/policy/projects/solar-radiation-governance/report/ Schaeffer et al (2011) Amount and timing of permafrost carbon release in response to climate warming. Tellus B, Wiley online library 63(2):165–180, April 2011. http://onlinelibrary.wiley. com/doi/10.1111/j.1600-0889.2011.00527.x/abstract

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Tarnocai C et al (2009) Soil organic carbon pools in the northern circumpolar permafrost region. Global Biogeochem Cycles 23, GB2023 UN (2011) http://www.un.org/apps/news/story.asp?NewsID¼38253 Walker B et al (2009) Looming global-scale failures and missing institutions. Science 325:1345–1346 Wigley T (2006) A combined mitigation/geoengineering approach to climate stabilization, science. Science 314(5798):452–454

Stratospheric Sulfate Aerosols and Planetary Albedo

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Contents Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Formation of Sulfate Aerosols and Aerosol Microphysics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sulfate Aerosols and Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sulfate Aerosols and Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

A considerable cooling of the Earth’s surface has been observed after major volcanic eruptions that injected large amounts of sulfur into the stratosphere. The enhanced burden of sulfate aerosols resulted in an increase of the planetary albedo and a significant decrease of incoming solar radiation. This effect is often reported as an analogue to proposed solar radiation management (SRM) geoengineering schemes. Model studies have indicated that the artificial injection of sulfate aerosols into the stratosphere, in conjunction with aggressive reductions in greenhouse gas emissions, may forestall or prevent temperatures from rising and Arctic sea ice from melting until greenhouse gas levels subside. Such a climate engineering approach may be relatively inexpensive, but would impact stratospheric chemistry and dynamics, as well as the hydrological cycle. Keywords

Climate engineering • Geoengineering • Solar radiation management • Stratospheric aerosol • Ozone depletion

S. Tilmes (*) • M. Mills National Center for Atmospheric Research, Boulder, CO, USA e-mail: [email protected]; [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_11, # Springer Science+Business Media Dordrecht 2014

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Definitions Sulfate aerosols are abundant in the stratosphere at background levels for volcanically quiet periods or at enhanced levels after volcanic eruptions. After some major eruptions, including El Chicho´n in March and April 1982 and Mt. Pinatubo in June 1991, the massive injection of gas-phase sulfur into the stratosphere produced an enhanced burden of stratospheric sulfate aerosols within a few weeks. These aerosols were larger than background aerosols and were distributed within a year over the entire hemisphere or globe. They remained in the stratosphere for several years after these eruptions. A significant increase of particles in the stratosphere results in an enhanced reflectivity of the planet, the Earth’s albedo. Smaller volcanic eruptions, as well as other natural and anthropogenic sources of sulfur, contribute to the background level of sulfate aerosols. Volcanic and background stratospheric aerosols reduce incoming shortwave radiation and therefore the Earth’s climate. Stratospheric sulfate aerosols are therefore climate forcing agents.

Formation of Sulfate Aerosols and Aerosol Microphysics The field of aerosol microphysics encompasses the processes that affect the formation and evolution of aerosol size distributions in the atmosphere. Such processes include nucleation, condensation, evaporation, coagulation, and sedimentation. These processes determine the size and atmospheric distribution of aerosols, which affects their impact on chemistry and climate. Sulfur injected directly into the stratosphere from volcanic eruptions is primarily in the form of gas-phase SO2, which then oxidizes to produce gas-phase H2SO4. Either of these gases may be introduced into the stratosphere for geoengineering purposes. Binary nucleation is the process by which H2SO4 and H2O gas form new sulfate aerosol particles. This process may take the form of gas-to-particle conversion (homogeneous nucleation) or may occur on preexisting nuclei, such as dust or smoke particles in the stratosphere (heterogeneous nucleation). Both processes occur faster where temperatures are low and water vapor is relatively abundant, such as near the tropical tropopause. In addition to forming new particles, H2SO4 gas may condense on preexisting sulfates, driving growth. Sulfates that are transported to higher altitudes in the stratosphere are likely to experience higher temperatures, which drive evaporation of H2SO4 off of the sulfates and back into the gas phase. Water also condenses and evaporates on sulfates, equilibrating to changes in temperature more rapidly than H2SO4 due to the higher concentrations of water vapor in the stratosphere relative to H2SO4 gas. These binary solutions in the stratosphere provide surfaces for heterogeneous reactions that influence atmospheric chemistry. In the extremely cold winter polar lower stratosphere, sulfate aerosols take up significant amounts of water, and nitric acid begins to condense on them as well, producing various forms of polar stratospheric clouds, which, in addition to the binary solutions, trigger catalytic ozonedestroying cycles.

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Coagulation happens when aerosol particles collide with each other, producing one larger particle from two smaller ones. The resulting larger, but fewer, particles reduce the aerosol surface area available to scatter sunlight. This is a potential problem for geoengineering, as introduced small particles may coagulate with existing large particles, limiting their effects on surface cooling. Aerosols can remain suspended in the atmosphere because their small size is supported by kinetic energy of atmospheric gases. During background conditions, sulfate aerosols are quite small with a typical effective radius of 0.17 mm. As aerosols grow to reach radii larger than 0.5 mm, they begin to sediment at significant rates, falling through the atmosphere that once supported them. Such large particles may result from large volcanic eruptions or geoengineering, and sedimentation reduces the lifetime of aerosols in the stratosphere. Hence sedimentation and coagulation may represent a limitation to geoengineering as more sulfate is introduced to offset more global warming.

Sulfate Aerosols and Climate Stratospheric sulfate aerosols scatter sunlight as it passes through the Earth’s atmosphere toward the surface. Some of this scattered sunlight then escapes back to space, reducing the total energy that heats the Earth’s surface. The ratio of sunlight that is reflected by aerosols, clouds, ice, and other components of the Earth system to the total sunlight that shines on the Earth is called the planetary albedo. Stratospheric sulfate aerosols increase the planetary albedo to varying degrees, depending on their mass and size, resulting in a cooling of the Earth’s surface. In addition, sulfate aerosols absorb radiation and heat the stratosphere locally. The 1991 eruption of Mt. Pinatubo resulted in large increases in stratospheric aerosol burdens, as observed by satellites, ground-based, and in situ measurements (Thomason and Peter 2006). Elevated stratospheric sulfate levels were observed for the following 3–4 years. Global mean surface temperature fell by 0.14 – 0.5 K in 1992 and remained cooler than average for 4–5 years after the eruption (Soden et al. 2002; Canty et al. 2013). A reduction in precipitation was also deduced from observations (Trenberth and Dai 2007). Other volcanoes in the past had much larger impacts on temperatures and climate. In 1815, Mount Tambora in Indonesia produced what may have been the most explosive eruption of the last 10,000 years. On the other side of the globe, the following year became known as the “year without a summer,” as New England experienced snows or frosts in every month of the year, sparking a mass migration of farmers to the south and west. As crops failed in North America and Europe, wheat reached its highest price in the nineteenth century in New York and Europe. Global average temperature is estimated to have fallen by 0.4–0.7  C, with regional decreases of 1–2.5  C throughout New England and Western Europe (Stommel and Stommel 1983). Evidence of similar climatic cooling events following ancient volcanic eruptions has also been collected. The submarine caldera of Kuwae, in what is now the

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Republic of Vanuatu, is thought to have produced the second largest eruption in human history, in late 1452 or early 1453. Chinese records indicate that tens of thousands of people and animals froze to death in 1453, Yellow Sea ice extended more than 20 km out from shore, and southern China experienced an unprecedented 40 days of snow. Records also show extensive crop damage in Germany and Sweden for 1453–1462, and tree rings around the world show frost damage for that period (Pang 1991). Observations from ice cores and model simulations have led researchers to suggest that volcanic cooling may in some cases be sustained for centuries. An unusual 50-year period in the late thirteenth century, during which four volcanoes, starting with the 1257 Samalas eruption in Indonesia, injected large sulfur burdens into the stratosphere, may have produced an abrupt onset of the “Little Ice Age,” a period of cooler surface temperatures that persisted until the mid-nineteenth century. Models suggest that the cooling may be maintained by ocean/sea-ice feedbacks that persist long after the volcanic aerosols have been removed. The Kuwae eruption may have then produced a second pulse of cooling in the middle of the Little Ice Age (Miller et al. 2012; Lavigne et al. 2013). In addition to the cooling of the Earth’s surface, volcanic aerosol heats the stratosphere. The 1991 Mt. Pinatubo eruption was observed to heat the stratosphere in the tropics by up to 3–4 K, changing the temperature gradient between low and high latitudes. This strengthened the polar vortex, producing colder temperatures in the polar stratosphere. As we discuss in the next section, these colder temperatures and the increased aerosol levels had consequences for the ozone layer. The artificial injection of stratospheric aerosols has been proposed to cool surface temperature and counteract global warming from increasing greenhouse gases (Crutzen 2006). Model studies suggest that the reduction of incoming sunlight can reduce temperatures globally, but generally with a stronger cooling in the tropics than at high latitudes (Schmidt et al. 2012; Kravitz et al. 2013). The cooling of the Earth’s surface depends on the mass and size of sulfate particles, which vary with the timing and location of injected particles, and to some degree on the type of particles (Heckendorn et al. 2009; Niemeier et al. 2010; Pierce et al. 2010; English et al. 2012). The cooling effects of increased albedo could be offset or possibly enhanced, if the added aerosol modifies the heat-trapping properties of cirrus clouds in the upper troposphere (English et al. 2012; Kuebbeler et al. 2012). Geoengineered aerosols may also induce changes in the ozone layer, in particular over high northern latitudes, which could further affect surface temperatures (Tilmes et al. 2009). In addition, geoengineering was shown to reduce the global hydrological cycle, with significant reductions of precipitations, especially over monsoon regions (Tilmes et al. 2013).

Sulfate Aerosols and Chemistry Changes in stratospheric aerosols influence the chemistry and therefore ozone in the stratosphere. The ozone abundance in the stratosphere is controlled by various

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ozone-destroying cycles. In the tropics and mid-latitudes, ozone loss is dominated by cycles involving oxides of nitrogen. In the lower stratosphere and in high latitudes, chlorine and bromine cycles become more important. Increases in stratospheric aerosol suppress nitrogen oxide concentrations, but increase oxides of chlorine, bromine, and hydrogen concentrations (Fahey et al. 1993; Mills et al. 1993). At current stratospheric levels of chlorine and bromine (which should decrease gradually over the 21st Century due to international agreements banning CFCs and other anthropogenic ozone-depleting substances), the total column ozone at middle and high latitudes could decrease significantly in response to enhanced in stratospheric sulfate, as it did after the 1991 eruption of Mt. Pinatubo. Geoengineering model studies suggest a net reduction of column ozone in middle and high latitudes by 2050 and with it a considerable increase in UV at the Earth’s surface (Tilmes et al. 2012). The recovery of the Antarctic ozone hole could be delayed by at least 40 years (Tilmes et al. 2008). Changes in stratospheric dynamics may further have an influence on the ozone layer. A potential heating of the tropopause due to the sedimentation of geoengineered aerosols might further reduce the ozone abundance in the stratosphere due to increases in stratospheric water vapor (Heckendorn et al. 2009).

Conclusions Stratospheric aerosol is an important forcing agent of the Earth’s climate. Aerosols scatter incoming sunlight back to space, enhancing the planetary albedo and cooling the troposphere and Earth’s surface. They also heat the stratosphere, which induces dynamical changes, influence ozone chemistry, and may alter cloud properties, which results in further climate effects. The introduction of sulfate aerosols into the stratosphere for solar radiation management geoengineering could produce complex feedbacks in the climate system that may not be intended or desired. Reductions in precipitation and stratospheric ozone have been observed accompanying recent large volcanic eruptions that have cooled global temperatures. The impacts of stratospheric aerosol geoengineering are still not well understood, especially microphysical and chemical processes and their feedbacks on climate.

References Crutzen PJ (2006) Albedo enhancement by stratospheric sulfur injections: a contribution to resolve a policy dilemma? Clim Change 77(3):211–220 English JM, Toon OB, Mills MJ (2012) Microphysical simulations of sulfur burdens from stratospheric sulfur geoengineering. Atmos Chem Phys 12(1):4775–4793. doi:10.5194/acp12-4775-2012 Fahey DW et al (1993) In situ measurements constraining the role of sulphate aerosols in midlatitude ozone depletion. Nature 363(6429):509–514

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Heckendorn P, Weisenstein D, Fueglistaler S, Luo BP, Rozanov E, Schraner M, Thomason LW, Peter T (2009) The impact of geoengineering aerosols on stratospheric temperature and ozone. Environ Res Lett 4:5108. doi:10.1088/1748-9326/4/4/045108 Kravitz B, Caldeira K, Boucher O, Robock A, Rasch PJ, Alterskjær K, Bou Karam D, Cole JNS, Curry CL, Haywood JM, Irvine PJ, Ji D, Jones A, Kristja´nsson JE, Lunt DJ, Moore J, Niemeier U, Schmidt H, Schulz M, Singh B, Tilmes S, Watanabe S, Yang S, Yoon J-H (2013) Climate model response from the Geoengineering Model Intercomparison Project (GeoMIP). J Geophys Res 118(15):8320–8332. doi:10.1002/jgrd.50646 Kuebbeler M, Lohmann U, Feichter J (2012) Effects of stratospheric sulfate aerosol geo-engineering on cirrus clouds. Geophys Res Lett 39(23). doi:10.1029/2012GL053797 Lavigne F et al (2013) Source of the great A.D. 1257 mystery eruption unveiled, Samalas volcano, Rinjani Volcanic Complex, Indonesia, pnas.org. doi:10.1073/pnas.1307520110 Miller GH et al (2012) Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks. Geophys Res Lett 39:02708. doi:10.1029/2011GL050168 Mills MJ, Langford AO, O’Leary TJ, Arpag K, Miller HL, Proffitt MH, Sanders RW, Solomon S (1993) On the relationship between stratospheric aerosols and nitrogen dioxide. Geophys Res Lett 20:1187. doi:10.1029/93GL01124 Niemeier U, Schmidt H, Timmreck C (2010) The dependency of geoengineered sulfate aerosol on the emission strategy. Atmos Sci Lett 12(2):189–194. doi:10.1002/asl.304 Pang KD (1991) The legacies of eruption – matching traces of ancient volcanism with chronicles of cold and famine. Sciences 31(1):30–35 Pierce JR, Weisenstein DK, Heckendorn P, Peter T, Keith DW (2010) Efficient formation of stratospheric aerosol for climate engineering by emission of condensible vapor from aircraft. Geophys Res Lett 37(18): n/a–n/a. doi:10.1029/2010GL043975 Schmidt H, Alterskjær K, Bou Karam D, Boucher O, Jones A, Kristja´nsson JE, Niemeier U, Schulz M, Aaheim A, Benduhn F, Lawrence M, Timmreck C (2012) Solar irradiance reduction to counteract radiative forcing from a quadrupling of CO2: climate responses simulated by four earth system models. Earth Syst Dyn 3(1):63–78. doi:10.5194/esd-3-63-2012 Soden BJ, Wetherald RT, Stenchikov GL, Robock A (2002) Global cooling after the eruption of Mount Pinatubo: a test of climate feedback by water vapor. Science 296(5):727–730. doi:10.1126/science.296.5568.727 Stommel H, Stommel E (1983) Volcano weather: the story of 1816, the year without a summer. Seven Seas Press, Newport Thomason LW, Peter T (eds) (2006) Assessment of Stratospheric Aerosol Properties (ASAP). SPARC Report No. 4, WCRP-124, WMO/TD-No. 1295, Available at http://www.atmosp. physics.utoronto.ca/SPARC/index.html Tilmes S, M€uller R, Salawitch R (2008) The sensitivity of polar ozone depletion to proposed geoengineering schemes. Science 320:1201. doi:10.1126/science.1153966 Tilmes S, Garcia RR, Kinnison DE, Gettelman A, Rasch PJ (2009) Impact of geoengineered aerosols on the troposphere and stratosphere. J Geophys Res 114:12305. doi:10.1029/2008JD011420 Tilmes S, Kinnison DE, Garcia RR, Salawitch R, Canty T, Lee-Taylor J, Madronich S, Chance K (2012) Impact of very short-lived halogens on stratospheric ozone abundance and UV radiation in a geo-engineered atmosphere. Atmos Chem Phys 12(2):10945–10955. doi:10.5194/acp-1210945-2012 Tilmes S, Fasullo J, Lamarque J-F, Marsch DR, Mills M, Alterskjær K, Boucher O, Cole JNS, Curry CL, Haywood JM, Irvine PJ, Ji D, Jones A, Karam DB, Kravitz B, Kristja´nsson JE, Moore JC, Muri HO, Niemeier U, Rasch PJ, Robock A, Schmidt H, Schulz M, Singh B, Watanabe S, Yang S, Yoon J-F (2013) The hydrological impact of geoengineering in the Geoengineering Model Intercomparison Project (GeoMIP). J Geophys Res 118 (19):11036–11058. doi:10.1002/jgrd.50868 Trenberth KE, Dai A (2007) Effects of Mount Pinatubo volcanic eruption on the hydrological cycle as an analog of geoengineering. Geophys Res Lett 34(15), L15702. doi:10.1029/ 2007GL030524

Cloud Brightening and Climate Change

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Hannele Korhonen and Antti-Ilari Partanen

Contents Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aerosols and Cloud Albedo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cloud Brightening with Sea-Salt Aerosol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Climate Effects of Cloud Brightening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Atmospheric greenhouse gas emissions show no declining trend, which has motivated ideas of deliberate climate engineering by modifying the reflectivity of the Earth. One suggested method is cloud brightening, in which artificial emissions of aerosol particles are used to enhance the reflectivity of clouds. While climate models suggest that cloud brightening might be able to offset at least some of the predicted global warming, large uncertainties remain related to the efficiency as well as to the environmental and regional climate impacts of the method. Keywords

Climate engineering • Geoengineering • Solar radiation management • Cloud whitening • Aerosol • Sea salt

H. Korhonen (*) • A.-I. Partanen Finnish Meteorological Institute, Kuopio, Finland e-mail: [email protected]; [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_50, # Springer Science+Business Media Dordrecht 2014

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Definitions Cloud brightening is a climate engineering method which aims to decrease the global temperature by deliberately injecting sea spray aerosol particles into the atmosphere in regions with persistent marine stratocumulus clouds. Cloud condensation nucleus (CCN) is an atmospheric aerosol particle about which supersaturated water vapor can condense to form a cloud droplet. Cloud albedo effect (i.e., first indirect effect) of aerosol particles refers to the mechanism by which aerosols modify the cloud droplet concentration and hence the reflectivity of the clouds.

Aerosols and Cloud Albedo Clouds are an important regulator of the Earth’s energy balance. On a global scale, they block about one fifth of the solar radiation from reaching the planet’s surface and at the same time also trap a large fraction of the thermal radiation emitted by the Earth’s surface and prevent it from escaping into space. These two effects of the clouds have opposite effects on the surface temperature below them: the former prevents the absorption of some of the sun’s energy at the surface and thus causes cooling, whereas the latter tends to warm the surface. (See chapter ▶ Global Climate Change, Introduction and ▶ Radiative Forcing and the Greenhouse Gases for more detailed discussion on clouds and radiation.) The amount of solar radiation that the clouds are capable of reflecting back into space depends strongly on the atmospheric conditions, for example, on humidity, temperature profile, and convection. However, for many types of clouds, it also depends on the number concentration of atmospheric aerosol particles, which can act as nuclei for cloud droplet formation. The increase in aerosol particles available as cloud condensation nuclei (CCN) typically increases the optical thickness (i.e., reflectivity) of the clouds. This is because when the same amount of cloud water is divided among more numerous droplets, the total surface area of the droplets increases causing higher reflectivity. This effect is known as the cloud albedo effect (or first indirect effect) of aerosol particles. As a rule of thumb, the change in cloud albedo is proportional to the relative change in cloud droplet concentration, i.e., the reflective properties of clouds which have a low initial droplet concentration can be changed with less additional droplets than the properties of clouds that have a high initial droplet concentration. Because of this, the strength of the cloud albedo effect varies in different types of environments. Over the continents, there is typically a large abundance of aerosol particles that are suitable CCN, and thus, clouds have high cloud droplet number concentrations (several hundred or even couple of thousand per cubic centimeter). However, in remote marine regions the aerosol concentrations are often fairly low, around 100 droplets per cubic centimeter. Such low droplet concentrations make the albedo of marine stratocumulus clouds susceptible to brightening from changes in atmospheric aerosol concentrations.

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One example of the susceptibility of the marine clouds to a perturbation from aerosol injection is ship tracks, which can be detected from satellite images as long, thin and optically thick clouds following the ship plumes. Ship tracks form when the ships’ exhaust releases new sulfur-containing particles into the atmosphere, and these particles act as CCN upon cloud formation. As a clearly visible demonstration of the effect of aerosol particles on cloud albedo, the ship tracks have inspired ideas of modifying marine clouds by deliberately injecting aerosol particles to regions with persistent cloud cover in order to “brighten” the marine clouds and thus to cool the climate.

Cloud Brightening with Sea-Salt Aerosol The use of deliberate aerosol injections in order to increase the reflectivity of marine stratocumulus clouds was first suggested several decades ago (Latham 1990). Current research on the topic concentrates on artificial emissions of sea spray which could be produced with a fleet of unmanned, wind-powered vessels that can be remotely steered beneath marine clouds and emit seawater droplets into the air at a very high rate (Fig. 89.1) (Salter et al. 2008). Once in the atmosphere, the water from the injected droplets will evaporate leaving behind particles consisting mainly of sea salt. It is currently uncertain how large a fraction of the released particles would be transported to altitudes where they could act as CCN and thus increase the cloud droplet concentration compared to an unperturbed situation. The efficiency of artificial cloud brightening is expected to be highly dependent on several factors, such as the effect of droplet evaporation on the atmospheric temperature profile, vertical velocity of atmospheric flows, and background aerosol concentration (Korhonen et al. 2010). For marine regions to be suitable for cloud brightening, they must be frequently occupied by persistent low-lying stratocumulus decks, so that particles injected close to the sea surface can easily reach the cloud base. In order to have a significant effect on the global radiation balance, the injection regions should also receive a fair amount of solar radiation. Based on these requirements, several climate model studies have identified the stratocumulus regions off the west coasts of North and South America and of Southern Africa as the most suitable all-year-round injection sites. It should be noted, however, that also other regions might prove favorable if the additional aerosol particles were released into the atmosphere directly at the cloud altitude (e.g., from planes) instead of at the ocean surface. It has also been previously suggested that marine clouds could be brightened by fertilizing the oceans with iron in order to enhance dimethyl sulfide (DMS) emissions from phytoplankton. The gaseous DMS is known to get oxidized in the atmosphere after which it can form new aerosol particles to act as CCN. However, a wealth of recent field observations and modeling studies has shown that even large increases in DMS emissions will probably not lead to significant cloud brightening (Quinn and Bates 2011).

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Fig. 89.1 Schematic illustration of the suggested cloud brightening and cloud albedo effect. The vessel injects seawater droplets that evaporate and the remaining sea-salt particles are transported to the cloud level. They act as cloud condensation nuclei and increase the cloud droplet concentration and thus cloud reflectivity. Particles that end up outside clouds also scatter solar radiation, but the effect is minor compared to the cloud albedo effect

Climate Effects of Cloud Brightening To date, no large-scale experiments of cloud brightening have been conducted, and therefore, atmospheric models are currently the only source of estimates on the potential cooling efficiency of cloud brightening. Several climate model studies have indicated that cloud brightening could significantly cool the planet provided that one could at least quadruple the natural cloud droplet concentration (from about 100 cm 3 to about 400 cm 3) over large fraction of the oceans. It has been estimated that under the unrealistic assumption that all marine low-level clouds were modified, the resulting cooling could more than offset the warming from doubling of preindustrial atmospheric CO2 concentration (Latham et al. 2008). On the other hand, if only the most suited stratocumulus regions off the coasts of the Americas and Southern Africa (comprising approximately 3 % of the Earth’s surface area) were modified, cloud brightening could counteract about 35 % of the warming of doubled CO2 concentration and postpone global warming by 25 years (Jones et al. 2009). It is important to notice that even though large-scale cloud brightening might be able to help restore the global mean temperature to preindustrial values as well as preserve the polar ice sheets, climate models suggest that cloud geoengineering would result in large regional differences in temperature change (Rasch et al. 2009). While this is likely to be true also for other climate engineering methods that reflect sunlight back into space, the effect could be even stronger for cloud brightening due to the strong localized modification of the energy balance. The regions experiencing most cooling would likely be found under or close to the modified clouds, although also the Arctic could experience significant cooling (Jones et al. 2009).

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Many potential environmental effects of strong localized cooling remain uncertain, but concerns have been raised, e.g., the effects on ocean currents, marine ecosystems, as well as large-scale weather patterns such as El Nin˜o. Large-scale cloud brightening is predicted to decrease global mean precipitation because less sunlight reaching the Earth’s surface would reduce evaporation from the surface and thus also reduce the atmospheric water available for rain formation (Rasch et al. 2009). However, different climate models and cloud brightening scenarios give very different results with respect to the geographical distribution of the precipitation change. For example, one model study has predicted a very strong decrease of rainfall over the Amazonia with potentially detrimental consequences on vast areas of rain forest (Jones et al. 2009). This effect has not, however, been reproduced by other models which highlights the uncertainty of predicting future precipitation changes. Overall, while cloud brightening may be able to counteract at least some of the precipitation increase resulting from increased CO2 concentrations on a global scale, it is very unlikely that even the global means of temperature and precipitation could be simultaneously kept at present-day values. While most climate model studies to date have assumed that the cloud droplet concentration could be increased fairly homogeneously in large regions over the oceans, this is unlikely to be the case in the real atmosphere. More detailed studies of the fate of the injected particles have revealed that spatial heterogeneity is highly likely, in part due to varying background concentrations and transport in the atmosphere (Korhonen et al. 2010; Partanen et al. in press). Furthermore, according to simulations made with models that are able to resolve the structure of individual clouds, sea-salt injections would probably increase the cloud reflectivity only under certain favorable meteorological conditions and have negligible effect under others (Wang et al. 2011). A further concern with the brightening efficiency is that poor mixing of the injected particles with the surrounding air could lead to a requirement of a very large number of spraying vessels in order to spread particles into a sufficiently large area. On the other hand, it has been recently found that even particles that are transported outside clouded areas could contribute to climate cooling by scattering solar radiation (so-called aerosol direct effect). This effect is, however, likely to be relatively small compared to the cloud albedo effect (Partanen et al. in press). One advantage of cloud brightening as a climate engineering option is that the lifetime of sea-salt particles in the atmosphere is short. Thus, should the need arise, the system could be stopped immediately after which the direct cooling effects would last only for a few days. It is, however, possible that some of the environmental effects caused by the method could be irreversible or take a long time to reverse even upon termination. Furthermore, it is crucial to understand that a shutdown of cloud brightening or any other climate engineering method in a world with high greenhouse gas concentrations could lead to a very rapid warming with potentially large detrimental ecosystem and societal impacts.

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Conclusions Many climate model studies suggest that cloud brightening with sea-salt injections could have a significant effect on the Earth’s radiation balance and at least partly offset changes in global mean temperature and precipitation caused by increased greenhouse gas emissions. It is, however, clear that regional climate conditions could not be restored simultaneously everywhere on the globe. In addition, recent studies suggest that the first climate simulations may have been overly optimistic concerning the efficiency of cloud brightening. It is therefore too early to estimate the costs of deploying the method on a large scale. Further improvement of the scientific understanding on the feasibility or efficacy of cloud brightening would require controlled small-scale field studies of cloud seeding with sea-salt aerosol. Such experiments would be considerably easier to conduct with minimal effects on the surrounding environment than those testing climate engineering with stratospheric sulfate particles. However, proposals of any field studies on these methods currently face opposition from the general public based on the moral and ethical issues of climate engineering.

References Jones A, Haywood J, Boucher O (2009) Climate impacts of geoengineering marine stratocumulus clouds. J Geophys Res 114:D10106. doi:10.1029/2008JD011450 Korhonen H, Carslaw KS, Romakkaniemi S (2010) Enhancement of marine cloud albedo via controlled sea spray injections: a global model study of the influence of emission rates, microphysics and transport. Atmos Chem Phys 10:4133–4143 Latham J (1990) Control of global warming? Nature 347:339–340 Latham J, Rasch P, Chen C-C, Kettles L, Gadian A, Gettelman A, Morrison H, Bower K, Chourlaton T (2008) Global temperature stabilization via controlled albedo enhancement of low-level maritime clouds. Philos Trans R Soc A 366:3969–3987 Partanen A-I, Kokkola H, Romakkaniemi S, Kerminen V-M, Lehtinen KEJ, Bergman T, Arola A, Korhonen H (2012) Direct and indirect effects of sea spray geoengineering and the role of injected particle size. J Geophys Res 117, D02203, doi:10.1029/2011JD016428 Quinn PK, Bates TS (2011) The case against climate regulation via oceanic phytoplankton sulphur emissions. Nature 480:51–56 Rasch P, Latham J, Chen C-C (2009) Geoengineering by cloud seeding: influence on sea ice and climate system. Environ Res Lett 4. doi:10.1088/1748-9326/4/4/045112 Salter S, Sortino G, Latham J (2008) Sea-going hardware for the cloud albedo method of reversing global warming. Philos Trans R Soc A 366:3989–4006 Wang H, Rasch PJ, Feingold G (2011) Manipulating marine stratocumulus cloud amount and albedo: a process-modelling study of aerosol-cloud-precipitation interactions in response to injection of cloud condensation nuclei. Atmos Chem Phys 11:4237–4249

Maintaining and Enhancing Ecological Carbon Sequestration

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Bill Freedman

Contents Ecological Carbon Sequestration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ecological Carbon Sinks and Carbon-Offset Trading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Certifiability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Permanence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Leakage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ecological Carbon Sequestration and the Conservation of Biodiversity . . . . . . . . . . . . . . . . . . . . . . Environmental Influences on Carbon Sequestration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Carbon Storage in Terrestrial Ecosystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Forests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Grasslands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wetlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cross-References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

Terrestrial ecosystems sequester large amounts of organic carbon (C) in their pools of living and dead biomass. Management actions that increase C uptake and storage in ecological C pools, or that reduce C release from them, contribute to a society’s climate change mitigation objectives. They do this by reducing the rate of accumulation of CO2 and its radiative equivalents in other greenhouse gases (GHGs) in the atmosphere. Trading systems for GHG credits recognize the validity of ecological offset projects that result in increased C storage in the living and/or dead organic matter of ecosystems. In some circumstances, projects that reduce C release from existing high-C ecosystems are also considered to provide legitimate offsets. Some ecological carbon-offset projects

B. Freedman Department of Biology, Dalhousie University, Halifax, NS, Canada e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_12, # Springer Science+Business Media Dordrecht 2014

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have been criticized from a variety of perspectives, but the problems can mostly be dealt with by means of improved regulations and management actions. In addition to their contribution to climate change mitigation, projects that maintain or accumulate ecological carbon offsets often result in important co-benefits through the conservation of biodiversity and non-carbon environmental services, which are also important societal goals. The co-benefits are, however, much less substantial for projects based on intensively managed ecosystems, such as no-till agroecosystems and plantation forests, compared with those that restore or maintain habitats that are more natural in character. Keywords

Carbon sequestration (storage) • Ecological sequestration • Biomass, organic matter • Forest • Grassland • Wetlands • Greenhouse gas offsets • Climatechange mitigation • Biodiversity

Ecological Carbon Sequestration Climate change is one of the major global-scale environmental challenges that will be affecting human societies around the world for generations to come (Rockstro¨m et al. 2009). Increasing atmospheric concentrations of greenhouse gases (GHGs), principally caused by the combustion of fossil fuels and the clearing of forests, are altering the Earth’s carbon cycle and energy balance (Raupach and Canadell 2010). As a result, at levels ranging from the international to the local, policies are being developed and actions taken to reduce the rate of accumulation of GHGs in the atmosphere. One effective way of helping to reduce atmospheric CO2 is to conserve or enhance ecological carbon sinks – the amounts of carbon present in the living biomass and dead organic matter of ecosystems (Freedman and Keith 1996; Freedman et al. 2009; note that dry biomass has a carbon content of about 50 %). If this is done, then the increased ecological carbon storage can be viewed as offsets to the emissions of CO2 or its radiative equivalents in other GHGs as a result of various anthropogenic activities, such as the combustion of fossil fuels. These “ecological carbon offsets” (or “credits”) are gained by conserving already present natural sinks, and by management actions that enhance the uptake and fixation of atmospheric CO2 or that reduce its losses by decomposition or wildfire. Because atmospheric CO2 occurs in a well-mixed global reservoir, an ecological GHG-offset project can potentially be undertaken anywhere and the carbon credits assigned to a particular utility or other interest that is seeking to reduce its net emissions. Negotiations associated with the United Nations Framework Convention on Climate Change (UNFCCC 1992) have recognized the importance of ecological carbon sequestration in helping countries to reduce their net emissions of GHGs through so-called LULUCF activities (land use, land-use change and forestry).

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The creation of emissions-trading systems for GHGs helps to establish a price for GHG offsets and uses market forces to achieve reductions in their emissions where they can most efficiently be implemented. Emerging regional and national exchanges are already allowing the use of certain kinds of ecological carbon credits to offset anthropogenic emissions of GHGs. In these markets, projects that increase the fixation of atmospheric CO2 into ecosystem biomass relative to business as usual can be used to generate carbon credits, which may then be traded to GHG emitters that are seeking to reduce their net emissions. Typical strategies to increase longer-term ecological carbon storage involve increasing the area of forest (through afforestation or reforestation of lands), increasing the carbon density of forests (through changes to silvicultural activities or harvest rotations), and rehabilitating agricultural soil that is degraded in soil organic matter (through practices such as no-till agriculture) (IPCC 2007a). Some voluntary markets also allow projects that maintain existing carbon stocks to count as GHG offsets, such as by avoiding deforestation. Ecological carbon sinks in the LULUCF sector have the potential to make important contributions to climate-change mitigation by helping to reduce the amount of CO2 in the atmosphere. Essentially, the net fixation of CO2 is positive in any ecosystem in which the stocks of biomass are aggrading over time, as a consequence of the rate of photosynthesis exceeding that of respiration, decomposition, and direct emissions from disturbances such as fire. This results in a reduction of the CO2 content in the atmosphere and an increase in carbon storage in the ecosystem – in its living biomass and dead organic matter, including in soil. It has been estimated that almost 2,500 Gt (2.5
1012 t) of carbon are stored in global vegetation and soil (IPCC 2000). Forests contain about 46 % of this terrestrial pool (1,150 Gt), of which two-thirds (790 Gt) occurs in their soil. For comparison, the atmosphere contains about 806 Gt of carbon, almost all as CO2. In fact, it has been estimated that natural terrestrial carbon sinks are capable of offsetting 30 % of anthropogenic GHG emissions, and marine ones an additional 24 % (Canadell et al. 2007). It is likely, however, that the capacity of terrestrial ecosystems to act as sinks for GHGs will decline in the near future, because of additional deforestation and perhaps also as global warming intensifies. There are several major ways to manage terrestrial ecosystems in order to enhance sinks and reduce the emissions of GHGs. The first is to convert anthropogenic habitats with a low capacity for carbon sequestration into more productive ecosystems with a greater potential for accruing carbon stocks. This typically might involve a conversion from a low-C type of land use such as pasture or annually cropped fields, to a high-C forested condition. The forest might be established as a plantation intended primarily to provide wood products or bioenergy to meet societal demands, or as a more natural forested habitat developed through a project in ecological restoration. In fact, forest cover has become much more extensive over the past century in some regions, for example, across broad areas of eastern North America and Western Europe. This has mostly occurred through woody encroachment onto abandoned agricultural lands of marginal quality, although some areas have had plantations established. In the eastern USA, the increased storage of organic carbon in forests during the 1980s was equivalent to an offset of 10–30 % of that country’s

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emissions of fossil fuel CO2 (Houghton et al. 1999). Land use changes of these sorts, which result in increased storage of carbon in the living biomass and dead organic matter of the affected ecosystems, only count as carbon offsets in trading systems when the actions are deliberate and the enhanced C uptake is in addition to any that would have occurred under a business-as-usual scenario. Another ecological tactic for achieving net reductions of GHG emissions is to conserve natural habitats that are already storing large amounts of organic carbon (i.e., existing high-C reservoirs). Whenever tracts of forest, grassland, or wetland are converted into agricultural or urbanized land uses, there are large emissions of CO2 because much of the amassed stocks of carbon in living vegetation and organic matter in soil become oxidized by decomposition or burning (Freedman and Keith 1996; Houghton 2003; Freedman et al. 2009). Often, the conversion results in a decrease in the net productivity of the ecosystem (i.e., in its rate of CO2 fixation) and in its capacity to store additional organic carbon (because the system is not allowed to progress to an older-growth condition). In fact, Houghton (2003) estimated that global changes in land use between 1850 and 2000 had resulted in a net release of 156 Gt of carbon, mostly as a result of deforestation to develop agricultural land. Clearly, the conservation of high-C natural ecosystems helps to avoid such additional emissions. Annex I parties to the Kyoto Protocol (these include most of the world’s developed countries) are already accountable for these emissions, and they obtain credit directly by reducing them. There are, however, extensive opportunities to avoid the loss or degradation of high-C natural ecosystems outside these Annex I countries. The REDD+ mechanism (Reduced Emissions from Deforestation in Developing Countries) will provide incentives to reduce these emissions by financing initiatives that reduce deforestation and degradation in developing countries. Additional LULUCF-related opportunities include: the practice of no-till agriculture to increase the organic-carbon content of agricultural soils, as well as the use of renewable biofuels to displace nonrenewable fossil fuels as sources of commercial energy, and forest-product materials to replace more C-intensive building products. In this chapter, however, we focus on ecological carbon offsets associated with the conservation and restoration of ecosystems. It is important to recognize that projects principally undertaken to enhance or maintain ecological carbon sinks may bring substantial non-carbon co-benefits, such as improved habitat for biodiversity (Freedman and Keith 1996; Bonnie et al. 2002; Freedman et al. 2009). It is essential to conserve biodiversity for the following reasons: (a) its intrinsic value; (b) some components are sources of foods, medicines, materials, or bioenergy; and (c) natural ecosystems provide vital environmental services, such as carbon storage and clean and predictable flows of fresh water. For these reasons, the conservation of biodiversity is an objective subject to its own international agreement, the Convention on Biological Diversity (1993) under the United Nations Environment Program. If carbon sequestration is assigned an economic value as an ecological service, then additional financial resources can potentially be marshaled to support projects to conserve biodiversity based on increased amounts of CO2 fixation and storage than might otherwise have occurred.

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Ecological Carbon Sinks and Carbon-Offset Trading Ecological carbon sinks have the potential to play an important role in helping society to achieve large reductions of atmospheric GHGs. It has been estimated that projects associated with afforestation, reforestation, reduced deforestation, and conservation tillage could potentially contribute 2.0–2.5 GtC/year in GHG offsets within about 50 years (Pacala and Socolow 2004). Nevertheless, it is important to understand that the role of ecological sinks is restricted by the limited land areas available to provide this function, and so the focus of societal actions must be on reducing or, otherwise, displacing the use of fossil fuels, rather than offsetting them. The Kyoto Protocol has established targets for many countries to reduce their emissions of CO2 and other GHGs, and has included provisions for carbon sinks in national GHG accounts (Article 3) and in emissions-trading systems (Article 6). The Clean Development Mechanism (CDM) and Joint Implementation (JI) are intended to encourage investment in international projects that reduce net global emissions of GHGs (Article 12). The CDM allows Annex-I “developed” countries, which have capped emissions of GHGs under the Kyoto Protocol, to receive credits toward their commitments by investing in projects in developing countries that would achieve a net reduction in GHG emissions. JI projects are similar but they involve agreements among developed countries. Both CDM and JI projects can include actions that gain ecological carbon credits, with progress toward meeting other (i.e., non-GHG) environmental and socioeconomic objectives also being a consideration, especially for CDM projects. Even before the Kyoto Protocol was implemented, the trading of emissions credits had gained acceptance as a market-economics approach to reducing the discharge of air pollutants. One example is the US system of trading SO2 emission credits, which has resulted in larger reductions than legally required at costs less than the highest forecasts (Sandor et al. 2002). Such trading systems can achieve their objective of reducing emissions in ways that avoid the “command and control” regulatory approach, which many economists view as being more disruptive to the larger economy and less able to exploit lower-cost opportunities to reduce pollution. Instead, systems of cap-and-trade and emission credits provide flexibility in the chosen methods, locations, and timing of reductions, while affirming the importance of such actions to society. When an emissions cap is decreased, or obligations to reduce them are raised by financial disincentives, there is a larger inducement for market players to reduce their emissions and if possible to generate offsets for sale. It should be noted, however, that unlike the US trading system for SO2, which is focused on large point sources, a carbon-trading system would likely be more broadly applied in the economy by including numerous smaller sources, and so its establishment would be a relatively complex undertaking. The policy, regulatory, and infrastructural elements needed to support national, regional, and global GHG emissions trading are becoming widely established. A number of tradable permit systems are in operation in addition to those established under the CDM and JI mechanisms of the Kyoto Protocol. The European Union’s Emission Trading Scheme (EU-ETS) is presently the largest GHG cap-and-trade

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system, and others include Japan’s Voluntary Emissions Trading System and the Chicago Climate Exchange (also voluntary). According to The World Bank (2010), the aggregate value of global carbon-trading markets was US$144 billion in 2009. Most of this occurred within the European Union Emission Trading System (EU-ETS), with a total value of US$118 billion. However, project-based ETS transactions were only US$3.4 billion, mostly within the context of CDM at US $2.7 billion (200 million t CO2e at an average price of US$12.7/t). Although ecological carbon-sink projects are accepted in GHG-offset trading systems, they may be controversial because of concerns about the accuracy and security of carbon credits that are claimed, as well as the contribution they will ultimately make to climate-change mitigation (Dembo and Davidson 2007; Freedman et al. 2009; Kapoor and Ambrosi 2010). The criticisms are various, and include the concern that some parties to the Kyoto Protocol could circumvent their emission-reduction targets because of windfall sinks, such as large naturally occurring carbon sinks (e.g., extensive tracts of forest) being treated as emission reductions in the accounting, and so helping to avoid actions to reduce the use of fossil fuels. However, many of the concerns about ecological carbon sinks can be addressed in straightforward ways.

Certifiability Some ecological carbon-offsets schemes have been criticized for their lax quantification and verification. However, these concerns are relevant to the monitoring of any kind of emissions and offsets of GHGs in a trading system. Any emissions-reduction project must provide accurate and certifiable reductions if they are to be registered into a formal trading system and held or exchanged there. Any issuing of offset credits should require that the following terms be met: (1) the use of standard and reliable quantification protocols; (2) verification of claimed emission reductions or offsets; (3) reputable certification, perhaps by a third party; and (4) a formal registry in the trading system. In fact, this level of rigor is normal across recognized offsettrading systems, and it makes the reliable tracking of reductions of net emissions possible. With regard to ecological carbon offsets, several agencies provide measurement guidelines and protocols based on standard methods of ecological quantification (IPCC 2007b; Pearson et al. 2007; WBCSD and WRI 2007).

Permanence Emissions of CO2 from the combustion of fossil fuels involves the release of carbon that has been geologically sequestered for millions of years into much more active sectors of its global cycle – the atmosphere and biological uptake and metabolic transformation. In this sense, ecological offsets are not “permanent,” because the organic carbon accumulated by a forest or grassland may become re-emitted to the atmosphere as CO2 as the result of a natural or anthropogenic disturbance.

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Although there are always risks of such “reversals,” they can be accounted for in an offset trading system by requiring that credits for lost carbon be insured, or replaced with another source of credits (such as tracts of forest held in reserve instead of being traded). It is also possible to greatly decrease the risk of reversals by managing areas that support ecological carbon credits in ways that reduce the frequency or severity of disturbances.

Additionality This is the requirement that an offset scheme be a deliberate mitigation, and not merely a situation in which advantage is taken of ecological carbon uptake or storage that is already naturally occurring. Additionality is a concern to some interests that are seeking to require parties to international agreements, such as the Kyoto Protocol, to produce tangible reductions in their emissions, or to develop new ecological carbon sinks. The too-easy alternative is to merely tally credits accrued from existing natural ecological sequestration that some well-forested countries are fortunate to have on an extensive basis. Consequently, ecological carbon-offset projects in the CDM must produce reductions of net emission that are “additional to any that would occur in the absence of the certified project activity” (Article 12). In the case of projects primarily undertaken to conserve natural ecosystems or wilderness, additionality would have to be demonstrated based on the undertaking not being economically viable without extra funding made available by selling carbon credits. Those monies might be required to purchase private property to establish a protected area, or to engage in longer-term stewardship afterward.

Leakage Leakage refers to carbon-offset projects that displace equivalent CO2 emissions to another location, and consequently do not provide a valid net reduction in emissions of GHGs. For example, the protection of an area of forest to provide GHG offsets may result in an equivalent amount of timber harvesting or agricultural conversion being displaced somewhere else, a leakage that would nullify any offsets claimed. Leakage is clearly an important issue, but it is common to all offset projects, and not just ecological ones.

Ecological Carbon Sequestration and the Conservation of Biodiversity Many land-management actions that are undertaken to enhance carbon sequestration or to protect existing stocks will also help to conserve biodiversity, and vice versa (Freedman et al. 2009). For example, avoided deforestation will prevent large emissions of ecologically sequestered carbon from occurring, while also conserving

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habitat for native biodiversity. As is explained below, these co-benefits are particularly relevant to natural habitats and much less so for anthropogenic ones. Afforestation refers to projects in which a forest is established on a site presently occupied by a non-forested form of land use, usually an agricultural one. Such conversions result in substantial carbon sequestration into woody biomass and other ecosystem components, providing verifiable offsets that can be registered and traded within Kyoto-related and other exchange systems. Afforestation also benefits biodiversity, particularly if an attempt is made to restore a facsimile of native forest appropriate to the ecoregion. There are additional environmental co-benefits related to water quality and decreased risks of erosion. Avoided conversion refers to projects that protect existing carbon stocks of ecosystems, particularly by avoiding the deforestation of natural forests. Although the CDM and JI do not recognize offsets from avoided deforestation, there is vigorous lobbying to include them in future agreements because deforestation results in such large GHG emissions. This is especially the case in tropical regions where, at the global level, most deforestation is now occurring in order to develop a larger agricultural land base. As was previously noted, avoided deforestation in less-developed countries would count as GHG offsets under the REDD+ scheme. Avoided deforestation is also vital to biological conservation, especially in tropical regions where most of the global biodiversity actually occurs. Forest management has a large influence on ecological carbon sequestration, in terms of both the rate of fixation and the average stocks maintained over the period of a harvest rotation. In addition, the diversion of harvested biomass into relatively enduring products such as buildings and furniture results in substantial delays in CO2 releases from the harvested biomass, compared with the faster turnover associated with biomass fuels or most uses of paper. When forest products are used in place of more energy-intensive materials, such as steel or concrete, substantial displacement of GHG emissions can occur. In general, the average carbon stocks and biodiversity co-benefits are greatest for “softer” management systems that emulate the natural disturbance regime typical for an ecoregion. Agricultural sinks include the ability of certain management practices, such as no-till planting systems, to enhance the organic matter of soil, thereby enhancing the beneficial property known as tilth (this is related to the favorable soil structure and the water-holding and nutrient-holding capacity of soil) while also increasing carbon sequestration. Another possibility is to convert lower-quality annually cultivated lands or tame pasture into grassland dominated by native species, which would increase carbon storage and help to conserve native biodiversity.

Environmental Influences on Carbon Sequestration Ecological carbon-offset opportunities differ among ecosystem types and regimes of land management (Freedman et al. 2009). The key influences on ecological carbon sequestration include: climatic and site factors, the disturbance regime, and

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the kinds of communities that develop. In general, higher-quality sites with a favorable climate will accumulate biomass carbon more quickly and to a larger steady-state amount, compared with less productive conditions. In addition, ecosystems subjected to frequent disturbances, whether natural or anthropogenic, will store much less living biomass and dead organic matter (on average over the rotation, or the period of time between harvests) than those affected less often. If the interval between disturbances is long enough, then old-growth ecosystems can develop, a situation in which the per-hectare carbon storage is maximized because it reaches an ecological asymptote. Climatic factors include the seasonality and amount of precipitation, surface temperature, and length of the growing season. In general, moderate climatic conditions support higher rates of productivity and larger accumulations of biomass. For example, a relatively moist and warm climate may inhibit wildfires and so favor the development of old-growth forest, which accumulates more biomass than any other kind of ecosystem and may do so for several centuries. In contrast, severe climate results in ecosystems that accumulate much less biomass, such as desert limited by moisture or tundra constrained by a short and cool growing season. Regions in which climatic conditions are limiting to ecological development have lower prospects for both the rate and per-hectare amount of carbon sequestration. Moreover, future climates may be characterized by an extensive occurrence of drier conditions in continental interiors, which might reduce the capacity of those regions to fix and store organic carbon. On the other hand, if warming allows boreal forest to invade tundra, there would be an increase in the potential for carbon sequestration. Site quality is a complex of soil-related factors such as tilth, nutrient and moisture availability, acidity or alkalinity, texture and mineralogy of the parent material, and drainage. Greater productivity occurs on higher-quality sites and they often support a larger accumulation of organic matter. Wet sites may store large amounts of dead organic carbon because the anaerobic conditions inhibit decomposition. Wetlands may, however, emit methane as a product of anaerobic decomposition, which counters some of the offsets associated with accumulating organic matter. Such methane emissions are extremely variable, but are relatively high for lower-latitude wetlands. Disturbance of any ecosystem reduces the rate of carbon fixation by damaging vegetation, while also depleting the stored biomass by combustion or by increasing the decomposition rate. Stand-replacing disturbances may be initiated by a wildfire, windstorm, insect outbreak, or disease and are typically followed by a successional recovery of positive net production during which there is a progressive re-accumulation of the stocks of biomass. The period of successional recovery is relatively long for forests, especially for old-growth types, but much shorter for grasslands. At the scale of landscape, stand-replacing disturbances influence carbon storage by affecting the age-class structure of the forest mosaic. Landscapes in which stands are frequently disturbed are more extensively dominated by younger communities that take up more carbon from the atmosphere, while those less often affected support larger areas of older stands that store more carbon. The plant community is also an important factor, because some species have an inherently high productivity, or grow large and store more carbon in biomass, or

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promote an accretion of dead organic matter. These biological factors are influenced by conditions affecting competition, such as tree density, and by other environmental factors such as those noted above. Moreover, the species and relative dominance of existing ecological communities will reorganize to better suit environmental conditions that develop in response to climate change, as less well-adapted species decline and better-suited ones become more abundant. Anthropogenic stressors and management regimes also greatly affect the rate and capacity of carbon sequestration in ecosystems. This is true of habitats that are already converted to agricultural or urbanized land uses, as well as natural ones that are affected by management practices either directly (e.g., by timber harvesting or livestock grazing) or indirectly (e.g., by fire suppression). Key anthropogenic influences are the following: The conversion of natural ecosystems, such as forest or grassland, into anthropogenic ones used for agricultural, residential, or industrial land uses results in large decreases in carbon storage in the living biomass and dead organic matter. Ultimately, the difference in carbon stocks is balanced by a large emission of CO2 to the atmosphere. Unlike a natural disturbance, such conversions are not followed by a re-accumulation of biomass during succession, because the recovery is prevented. Deforestation results in particularly large per-hectare emissions of CO2, and such conversions of forest into non-forested ecosystems have been responsible for about one-third of the anthropogenic emissions of CO2 since 1850. The conversion of older forest into plantations also results in a large net reduction of carbon storage, although this effect is much less than that caused by conversion to agricultural or urbanized land uses. The conversion of natural grassland into cultivated land results in a relatively small per-hectare loss of carbon stocks, but the aggregate releases of CO2 have been large because extensive areas have been affected. The draining of organic-rich wetlands to develop agricultural land also results in large emissions of CO2 from the decomposition of peat under newly oxidizing conditions. Anthropogenic disturbances include timber harvesting and fires caused by people. Anthropogenic disturbances are different from conversions in that successional recovery is possible, although not necessarily to the original ecological community. Although an anthropogenic disturbance is followed by a re-accumulation of biomass during succession, economic factors may prevent a full recovery. For example, after a clear-cut harvest of timber from a stand of natural old-growth forest, the recovery will be truncated because the regenerating trees become economically mature at a much younger age than that required to restore the old-growth condition. On the other hand, the rate of regeneration may be enhanced by reforestation, or the managed regeneration of harvested areas, which might include tree planting and other silvicultural practices. Over an entire rotation, however, secondary forests managed for timber production typically store much less organic carbon than comparable tracts of old-growth forest. Nevertheless, both at maturity and over the entire harvest rotation, managed forests store much more carbon than do deforested tracts that have been converted to agricultural or residential land uses.

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Other anthropogenic stressors that affect the rate and amount of carbon storage in ecosystems include pollution and any deterioration of climatic conditions. In general, a large increase in the intensity of environmental stressors will decrease the rate of net production and the asymptotic accumulation of biomass in an affected ecosystem. However, moderate increases of certain potential stressors may enhance carbon sequestration, as might be the case of modest rates of atmospheric deposition of nutrients such as gaseous NH4 and NOx or NO3 and NH4+ dissolved in precipitation, which may have anthropogenic sources. Management practices can be used to mitigate environmental stressors and thereby increase the rate and amount of biomass accumulation in managed stands. For example, dense stands of trees may be spaced to lessen competition, grasslands may be irrigated or fertilized to increase productivity, or disused pasture or heathland may be afforested to plantations or to more natural kinds of forest. There would even be longer-term GHG-offset benefits if stands were harvested when they reach economic maturity (instead of allowing succession to proceed to an oldergrowth condition), particularly if the timber was used to manufacture enduring wood products or as a biofuel to replace the use of fossil fuels (Stinson and Freedman 2001). However, this tactic would also reduce the co-benefits associated with biodiversity and environmental services.

Carbon Storage in Terrestrial Ecosystems Forests Forests are tree-dominated habitats, and they support much larger stocks of biomass carbon than any other kind of ecosystem. A mature tropical forest typically supports 225–375 tC/ha in its tree biomass and a productivity of 5–17 tC/ha year (Table 90.1), temperate forest 70–135 tC/ha and 5–6 tC/ha year, and boreal forest 45–100 tC/ha and 3–4 tC/ha year. However, old-growth forests accumulate much larger stocks of biomass, as is the case with the coastal conifer rainforest of the humid Pacific coast of North America, where 150–250 tC/ha is typical but more than 500 tC/ha may occur (Trofymow et al. 2008). Carbon storage in forests is greatly influenced by harvesting and management activities. The greatest effects are on the living biomass of trees, the amounts of which are reduced whenever timber is harvested, but organic carbon in woody debris and the forest floor may also be affected. In general, the amount of woody debris in natural forest is much greater than in stands managed for forestry purposes (Harmon et al. 1986). During a timber harvest, there is typically a deposition of logging debris, so the amount of woody material on the forest floor temporarily increases. If the harvested site is then converted to shorterrotation secondary forest, the amount of woody debris undergoes a long-term decline. However, timber harvesting has little effect on carbon stored in the soil, unless the site is converted for agricultural land use, after which the soil carbon may decline by 24–30 % (Freedman et al. 2009). Of course, the reverse

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Table 90.1 Typical carbon storage in biomass and productivity of global biomes (Whittaker and Likens 1973; Leith 1975) Biome Tropical rainforest Temperate deciduous forest Temperate conifer forest Boreal forest Temperate grassland Tundra and alpine meadow Desert and scrubland Rock and polar desert Swamp and marsh Lake and stream Annually cropped agri-land

Biomass (tC/ha) 225–375 70–135 80–>500a 45–100 3.5–7.0 0.5–3.0 0.5–3.0 0.0–0.1 12–68 0.05–0.1 17.5

Net primary productivity (tC/ha year) 5.0–17 5.0–5.4 5.9 2.5–3.6 2.3–2.5 0.65–0.7 0.32–0.35 0.0–0.07 10–11 2.3–2.5 0.5–20

a

The higher number is for old-growth rainforest on the humid west coast of North America

considerations are also true – if disused agricultural land is afforested to trees, there will be a large increase in the amount of organic carbon stored in the ecosystem. The dynamics of carbon fixation and storage capacity of a particular stand of forest are affected by a variety of biological and environmental factors, including the site conditions (related to fertility), species composition, stocking density of trees, and stage of ecological succession (related to recovery after a disturbance). In regions where commercial forestry is practiced, these influences are substantially captured by the yield and growth models that have been developed for use in predicting the amounts and distributions of harvestable biomass. At the landscape scale, there may be a dynamic mosaic of stands of various post-disturbance ages and occurring at different kinds of sites. However, these factors can be modeled and monitored to predict landscape-scale biomass, which can also be influenced by natural or anthropogenic disturbances, such as wildfire or timber harvesting. At a large scale, the models can be used to predict broad averages of forest biomass and carbon storage. For example, Myneni et al. (2001) calculated that forests in North America support a broad-scale average of 50.6 tC/ha in woody biomass, somewhat higher in the USA (57.9 tC/ha) than in Canada (44.0 tC/ha) because of extensive boreal stands in the latter. Table 90.2 shows typical data for the amounts of tree biomass in a representative sample of 100-year-old stands of natural forest and plantations from Canada. Some of the forest types are dominated by long-lived species and can maintain positive rates of net production at ages greater than 100 years, so the values reported are not the maximum attainable old-growth stocks. Data of this sort are readily available for all ecoregions and stand types of commercial forest in Canada, which comprise about half of its forested estate. The data for non-commercial boreal forests are less exact, but are nevertheless sufficient to provide reasonable estimates of carbon storage over large areas.

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Table 90.2 Carbon storage in a selection of typical stands of 100-year-old natural and plantation forests on good-quality forestry sites in Canada. Data are for trees only, in aboveground plus belowground biomass. The productivity data are averaged over the 100-year period. The data are from a compilation of information obtained from provincial departments of natural resources (Freedman and Keith 1995) Dominant species Natural Forest Sitka Spruce Douglas-fir Douglas-fir Spruces Spruce-Aspen Lodgepole Pine Trembling Aspen White Spruce Black Spruce White Pine Tolerant hardwoods Plantation Forest Douglas-fir Spruce

Location

Biomass (tC/ha)

Productivity (tC/ha year)

Humid Pacific temperate Humid Pacific coast Interior montane Interior montane Interior montane Interior montane Southern boreal Southern boreal Southern boreal Interior north temperate Interior temperate

474 485 182 212 220 223 282 154 128 196 127

4.7 4.9 1.8 2.1 2.2 2.2 2.8 1.5 1.3 2.0 1.3

Humid Pacific temperate Interior montane

273 178

2.7 1.8

Compared with trees, much less information is available for the biomass and carbon in other forest components, such as woody debris, forest floor, and soil. Nevertheless, these components are well known to store large amounts of organic carbon. Figure 90.1 illustrates data for the carbon content of aboveground vegetation, deadwood, and forest floor for two types of temperate forest in eastern Canada. Using Canada’s National Forest Carbon Monitoring Accounting and Reporting System, Stinson et al. (2011) estimated that 39 % of total forest C stocks, in addition to those noted in Fig. 90.1, typically occur in soils. Much of the organic carbon in forest soils is humified and resistant to decomposition. In typical boreal and temperate forests, where rates of decomposition of dead biomass are slow to moderate, more carbon may be stored in dead organic matter and soil than in living biomass. In tropical forests, however, the reverse is generally true because of much higher rates of decomposition. If the natural disturbance regime of a landscape is characterized by difficult-topredict disturbance events affecting vulnerable kinds of forest, such as wildfire, the age-class structure may be in a nonequilibrium condition. This may also be the case if the disturbance regime is changing, such as in response to drier conditions associated with climate change. Natural disturbances caused by wildfire and insect irruptions play a dominant role in many boreal landscapes, with the areas affected varying between years and over the longer term. During times of extensive stand-replacing disturbances, a forested landscape may be a net source of CO2 if emissions from damaged stands exceed the sequestration in undisturbed

796

a

B. Freedman Conifer Stands (n=3; 75-95 yr old; total biomass 139 tC/ha)

Hardwood Stands (n-3; 55-60 yr old; total biomass 140 tC/ha)

b

12%

14% 2% 5% 1%

6% 47% 15%

21%

59%

1% 17% trees (ag) snags

trees (bg) woody debris

shrubs forest floor

Fig. 90.1 Amounts of organic carbon (tC/ha) in major forest components in mature natural stands in eastern Canada. Data are for biomass carbon in trees (above and below ground) and shrubs and organic carbon in snags, woody debris, and forest floor (From Fleming and Freedman 1998)

areas (Kurz et al. 2008). In general, however, forests support a positive net fixation of CO2 at large spatial scales, and this is the reason why this kind of ecosystem is an important global sink for anthropogenic emissions of GHGs. It must be recognized that opportunities to generate carbon-offset credits in forested terrain are greatly influenced by the disturbance and management regimes. Even in older stands or landscapes where the forest is in a near-saturation condition of carbon sequestration, there are opportunities to prevent losses of fixed carbon by managing conditions to prevent or mitigate disturbances that might occur. One likely tactic would be the protection of older stands from timber harvesting or other anthropogenic disturbances, such as by designating protected areas where timber harvesting is not allowed. The carbon-offset benefits from tracts of protected forest will be greatest if there are relatively low risks of loss from natural disturbances or from mal-adaptation to future climatic conditions. Of course it is neither possible nor ecologically desirable to prevent all disturbances, but even partly effective measures such as fire management will result in the storage of larger stocks of organic carbon in stands and in landscapes than would otherwise have occurred.

Grasslands Grasslands are ecosystems dominated by graminoids (grasses and similar plants) and forbs (perennial non-grasses that die back to the ground surface in the autumn). They may store large amounts of organic carbon in their vegetation and soil, although much less than that occurs in forests (see Table 90.1). Temperate grassland, known as prairie or steppe, has a typical productivity of 0.5–7.5 tC/ha year (Leith 1975),

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Table 90.3 Carbon storage (tC/ha) in plant biomass and in soil organic matter of grasslands (Data are from Derner et al. (2006)) Grassland Tall-grass Mid-grass Short-grass

Plant biomass Above ground 1.9 0.9 0.5

Below ground 26.7 27.5 13.1

Soil carbon (to 30 cm) 61.4 58.5 18.8

Total ecosystem 90.0 86.9 32.4

but the amount of carbon storage varies greatly among the types of habitats, with tallgrass prairie supporting much more biomass than arid grasslands (Table 90.3). When natural grassland is converted into annually cropped farmland, within 10 to 20 years the organic matter stored in the ecosystem decreases by 20–40 % (Freedman et al. 2009). This is mostly a loss of organic matter in the surface soil caused by an increased rate of decomposition due to frequent tillage, often in association with less input of plant litter. The use of natural grasslands for cattle grazing may also reduce carbon storage, particularly in overgrazed systems. In contrast, when annually cropped agricultural land is converted into perennial grassland, the amount of carbon storage will increase. In Canada, the conversion of pasture dominated by either native grasses or alien “tame” ones will typically increase the organic carbon in soil by 25–59 tC/ha over about 20 years until a steady state is reached (Stinson and Freedman 2001). Other agricultural conservation practices will also increase the net sequestration of atmospheric CO2 into soil, including the use of no-till cultivation, improved fertilizer management, perennials in rotations, cover crops, and improved erosion control. Conant et al. (2001) found that the carbon content of agriculture soil typically increased by 30 % under a variety of regimes of improved management.

Wetlands Wetlands are habitats in which water occurs above or near the surface for a long enough time to promote the development of wet soil, water-loving vegetation, and related biological functions. There are two broad kinds of wetlands with regard to the storage and flux of organic carbon: (1) peatlands, most commonly occurring as bogs, which are ombrotrophic ecosystems, meaning they receive inputs of water and nutrients only from precipitation and atmospheric deposition and are consequently highly acidic, which, coupled with an anaerobic substrate means that slow decomposition encourages deep accumulations of peat that may exceed 10 m; and (2) mineral wetlands, such as fresh and estuarine marshes, shallow open water, and most fens and swamps, which get most of their water and nutrients from watershed sources and as such are less acidic and more fertile than peatlands and usually accumulate little or no peat because their climatic and substrate-related conditions favor decomposition.

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Depending on their type, wetlands play a complex role in carbon storage, in that they may contain large stocks of organic peat, but may also be an important source of biogenic emissions of CH4 and CO2. Dry peat is about 50 % carbon, and peatlands occupy about 3 % of the terrestrial surface but contain about 512
109 t of organic-C, equivalent to 16–33 % of the organic carbon of global soils (Maltby and Immirzi 1993; Bridgham et al. 2006). Although large amounts of peat may accumulate in peatlands, the rate of accretion is slow at only 20–100 cm per century (Gorham et al. 2003). Emissions from wetlands account for 91–237
106 t of CH4/year, compared with the global emission of 600
106 t/year (Ehhalt et al. 2001). These emissions are important because the greenhouse-warming potential of CH4 is about 25 times larger than that of CO2 on a per-molecule basis. Nevertheless, wetland systems can act as net sinks for greenhouse gases if their photosynthetic fixation of CO2 exceeds the release of CO2 plus CO2 equivalents of CH4 by respiration and decomposition. Analogously to the case of forests and grasslands, if natural wetlands are drained to develop agricultural or residential land, their accumulated store of organic carbon eventually oxidizes and contributes to increasing concentrations of atmospheric CO2. The same is true if peat is harvested and used as a source of energy, although the oxidation is much faster because the peat is burnt. In contrast, the conservation of natural wetlands helps to keep their organic carbon in place, and avoids these emissions. It will be important to understand the likely implications of climate change for efforts to conserve wetlands as carbon sinks. If decreased precipitation in a landscape results in a lower water table in peatlands, then the oxidation of surface peat will occur at faster rates. In northern peatlands, the loss of the permafrost could expose previously frozen organic substrates to higher rates of both oxidation and methane release.

Conclusions Offset trading is an established approach to assist in meeting goals to reduce the net emissions of GHGs, as required by international agreements such as the Kyoto Protocol and by national and other policy directives. Ecological carbon offsets are already playing an important role in emerging carbon markets, and this will increase in the future. Although ecological carbon sinks are not permanent, they do remove CO2 from the atmosphere and it is possible to mitigate many of the risks of reversals. At the same time, these ecological tactics often provide important co-benefits in terms of conserving habitat for biodiversity and for useful environmental services, such as providing clean water resources and preventing erosion. As such, ecological carbon offset projects can, if well designed, contribute toward maintaining a safe operating space for humanity within the contexts of climate change, the biodiversity crisis, and other critically important aspects of global environmental change (Rockstro¨m et al. 2009). Nevertheless, there is a

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limited role for ecological carbon offsets because of competition with other potential uses of much of the land base, especially for food production. Ultimately, the necessary reductions of emissions of CO2 and other GHGs must be met by economic transformations that result in much less use of fossil fuels as sources of commercial energy.

Cross-References ▶ Biogeochemical Cycling in Terrestrial Ecosystems - Individual Components, Interactions, and Considerations Under Global Change ▶ Carbon Sequestration in Soil and Vegetation and Greenhouse Gases Emissions Reduction ▶ Ecological Carbon Sequestration in the Oceans and Climate Change ▶ Global Climate Change, Introduction ▶ Land Management Options for Mitigation and Adaptation to Climate Change ▶ Land-Margin Ecosystems and Global Change ▶ Offset Systems and Greenhouse Gases ▶ Tradable Permits for Greenhouse Gases

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Trofymow JA, Stinson G, Kurz WA (2008) Derivation of a spatially explicit 86-year retrospective landscape-level forest carbon budget for the Oyster River area of Vancouver Island, BC. For Eco Manage 256:1677–1691 United Nations Framework Convention on Climate Change (UNFCCC), Conference of the Parties, Third Session (1997) Kyoto protocol to the United nations framework convention on climate change, FCCC/CP/1997/L.7/Add.1 United Nations. 1992. United Nations Framework Convention on Climate Change. UN, New York WBCSD and WRI (2007) Greenhouse protocol initiative. Towards a common standard for business reporting on greenhouse gas emissions. World Business Council for Sustainable Development and the World Resources Institute. http://www.ghgprotocol.org/templates/ GHG5/layout.asp?MenuID¼849. Accessed Sept 2007 Whittaker RH, Likens GE (1973) Carbon in the biota. In: Woodwell GM, Pecan EV (eds) Carbon and the biosphere. National Technical Information Service, U.S. Department of Commerce, Washington, DC, pp 281–302 World Bank (2010) Global carbon market grows to $144 Billion despite financial and economic turmoil. Press Release 26 May 2010. The World Bank, Washington, DC. http:// siteresources.worldbank.org/INTCARBONFINANCE/Resources/State_and_Trends_2010_ final.pdf. Accessed Feb 2011

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Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Space Sunshade Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reflectors at L1 Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Space Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Climate Modeling of Solar Constant Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Climate Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Space Sunshades Can Reduce the Magnitude of Climate Change . . . . . . . . . . . . . . . . . . . . . . . . Space Sunshades Could Lead to Altered Regional Climates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Space Sunshades Can Rapidly Cool the Earth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Space Sunshades Would Weaken the Global Water Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Space Sunshades Would Not Counteract the Direct Effects of CO2 . . . . . . . . . . . . . . . . . . . . . . Space Sunshades Do Not Mitigate CO2 Physiological Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Space Sunshades May Need to Be Maintained for Multiple Centuries . . . . . . . . . . . . . . . . . . . Failure of Sunshades Can Lead to Catastrophic Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

804 804 804 805 806 806 806 807 809 810 810 811 812 812 813 814

Abstract

The accelerated rate of increase in atmospheric CO2 concentrations in recent years and the inability of humankind to move away from carbon-based energy system have led to the revival of the idea of counteracting global warming through geoengineering schemes. Two categories of geoengineering proposals have been suggested: solar radiation management (SRM) and carbon dioxide removal (CDR) methods. SRM schemes would attempt to reduce the amount of solar radiation absorbed by our planet. Placing reflectors or mirrors in space, injecting aerosols

G. Bala Center for Atmospheric and Oceanic Sciences, Indian Institute of Science, Divecha Center for Climate Change, Bangalore, Karnataka, India e-mail: [email protected]; [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_25, # Springer Science+Business Media Dordrecht 2014

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into the stratosphere, and enhancing the albedo of marine clouds are some of the proposed SRM methods. In this section, the various space-based SRM methods which are likely to reduce the incoming solar radiation uniformly across the globe are discussed. In the past decade, the effects of these space sunshades on the climate system have been simulated using climate models by reducing the amount of incoming solar radiation by appropriate amounts (reduced solar constant). Key modeling results on the extent of global and regional climate change mitigation, unintended side effects, and unmitigated effects are briefly discussed. Keywords

Geoengineering • Solar radiation management • L1 Lagrange point • Space sunshades • Climate change • Global water cycle • Ocean acidification

Introduction Anthropogenic emissions of carbon dioxide and other greenhouse gases since preindustrial period have exerted a positive radiative forcing on the climate system by trapping longwave radiation (IPCC 2007). SRM aims to offset the warming influence from greenhouse gases by reducing the solar radiation absorbed by the planet by an amount that equals the increased longwave radiation absorption due to elevated levels of greenhouse gases. This can be achieved in two ways: (1) reducing the amount of solar radiation reaching the Earth and (2) increasing the reflectivity of the planet. Sunlight reaching the Earth can be reduced by space-based reflectors (Angel 2006; Early 1989; Seifritz 1989; Struck 2007). The reflectivity of the planet can be increased by increasing the albedo of persistent marine low clouds (Latham 1990; Latham et al. 2008) or enhancing the reflectivity of the land surface by whitening the roofs in urban areas (Akbari et al. 2009) or making the ocean surface more reflective (Evans et al. 2010). Reflectivity could be also increased by artificially injecting sulfate aerosols into the stratosphere (Budyko 1977; Crutzen 2006). Most SRM schemes are intentional, and since they operate on large spatial scales, they could result in large-scale modification to the global climate, and hence, they are also often known as “geoengineering” proposals (Keith 2001). In this section, we focus on the space-based SRM methods which are likely to reduce the incoming solar radiation uniformly across the globe. We also restrict our discussion to only the physical science aspects with a caveat that other concerns such as governance, ethical, economical, and political issues need to be considered and addressed before any field research or actual implementation. Further, our discussion is mainly centered on major results from climate modeling studies.

Space Sunshade Methods Space-based SRM schemes aim to reduce the amount of incoming solar radiation reaching the Earth. A number of techniques have been proposed to achieve this

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goal. We refer to the space-based SRM methods as either space sunshades or simply sunshades. It is estimated that a doubling of atmospheric CO2 causes a positive radiative forcing of approximately 3.5 Wm 2 (IPCC 2007). The amount solar radiation reduction needed to offset this forcing can be estimated from the radiative balance of the Earth system: since the amount of solar absorption by the planet is about 235 Wm 2, for the space-based techniques, a deflection of about 1.5 % reduction of incoming radiation is required (Royal Society Report 2009).

Reflectors at L1 Point Placement of reflecting mirrors, sunshades, and a cloud of small spacecrafts at L1 Lagrange point between the Earth and Sun has been suggested (Angel 2006; Early 1989; Seifritz 1989) as one of several space-based SRM options. At the L1 point, the gravitational forces of the Sun and Earth cancel each other exactly, and therefore, it is a stationary point where reflectors could be maintained at a minimal cost. L1 point is at a distance of 1.5  106 km from the Earth, about four times the distance between the Moon and the Earth. Early (1989) proposed the construction of a thin glass shield made from lunar materials and located near the L1 point of the Earth-Sun system (Early 1989). Earlier estimates (Seifritz 1989) suggested that a reduction in surface temperature of the planet by 2.5 K would require the reflection of the solar radiation by 3.5 %. This would be achieved by a reflector with an area of 4.5  1012 m2. The reflector could be made of aluminum with a density of 10 gm 2, for a total requirement of 45 million tons. The cost estimate for placing the reflector was 6 % of the world gross domestic product (GDP), or the then (1980s) military expenditure. Though L1 point is a stationary point in the rotating Sun-Earth system, it is unstable along the line connecting the Sun and Earth, and hence, the mirror has to be stabilized actively. Other techniques such as placing a sunshade consisting of a cloud of metersized thin “flyers” each weighing only a gram have been proposed (Angel 2006). More advanced concepts in optical design, transportation methods, and stabilization techniques could bring the cost of these sunshade flyers to as low as 0.5 % of the world GDP ($0.1 per year per ton of mitigated carbon) (Angel 2006). Placement of rings of particles and multiple spacecrafts at the Sun-Earth L1 point (Pearson et al. 2006) and micron-sized dust particles derived from comet fragments or lunar mining in orbits near the stable triangular Lagrange points (L4 and L5) of the Earth-Moon system have been also proposed (Struck 2007).

Space Mirrors The NAS report (NAS 1992) discussed a low-altitude alternative to the L1 Lagrange point. The idea is to place a low-orbit (200 km) parasol or a set of

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mirrors in space. Assuming 1 % of the surface area of Earth should be covered by the parasol to counter climate change from a doubling of CO2, the parasol should have an area of 5.5  1012 m2 (NAS 1992). The cost estimate range was $5.5–$55.0 trillion or $5.5–$55 per ton of mitigated carbon emissions. A single mirror would be unmanageable and would probably create problems in the regions where its shadow fell as it moved around the Earth (NAS 1992). If small set of mirrors with sizes of 108 m2 are deployed, about 55,000 mirrors would be required. By changing its angle to the Sun (and hence the solar radiation pressure forces on it), the orbit of each sail could be controlled. The NAS report (NAS 1992) concluded that this appears to be a very difficult, if not unmanageable, tracking problem. It is generally believed that it could take at least several decades to implement the space-based schemes and the cost of initial deployment could be high, but after the implementation, these schemes would reduce greenhouse-gas warming within a few years if greenhouse concentrations remained constant. If concentrations increase, incoming solar radiation needs to be reduced further by appropriate amounts. The technology development, engineering requirement, implementation and maintenance of space reflectors in space, and the associated cost need to be fully evaluated before any method is considered for practical purpose (McInnes 2010).

Climate Modeling of Solar Constant Reduction Climate Models How do we verify whether the Sunshade schemes or any SRM technique in general will mitigate the anthropogenic climate change caused by greenhouse gases? Climate models are the only experimental tools that can be used to investigate the sensitivity and future changes to the global climate system. Unlike in a chemistry or biology laboratory where one can perform multiple controlled experiments, it is not desirable to perform experiments with the global climate system. If the outcome of an experiment with our climate system goes awry, the consequences could be catastrophic. Indeed, the current debate on climate change, environmental damage, and sustainability stems from the unintentional experiment that we are performing on the planet, land use and land cover change, and the growth of atmospheric greenhouses gases and aerosols from the burning fossil fuels. Contemporary climate models have comprehensive three-dimensional numerical representation for the major components of the climate system and the interactions and feedbacks between them. Climate models are also known as general circulation models (GCMs). The early general circulation models solved only atmospheric equations of motion, and they are called atmospheric general circulation models (AGCMs). The contemporary models couple the atmosphere, oceans, land, and ice and are called coupled models or coupled atmosphere-ocean

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Fig. 91.1 Spatial and temporal distribution of the change in net longwave radiative flux at the tropopause when CO2 is doubled (left panel) and the change in shortwave radiative flux (right panel) that has the same global mean as the longwave flux changes in the left panel. The distribution of longwave fluxes is much more homogeneous than solar radiation which has the maximum in the tropics and exhibits strong seasonal variations in the middle and high latitudes. However, climate modeling studies (Govindasamy and Caldeira 2000; Govindasamy et al. 2002) have shown that the surface temperature change due to forcing in the left panel can be mitigated on a regional and seasonal basis (Fig. 91.2) by forcing shown in the right panel (with opposite sign)

general circulation models (AOGCMs). The state of the art in climate modeling is to couple the AOGCMs to the global carbon, nitrogen, and other biogeochemical cycles and to include interactive atmospheric aerosols and chemistry.

Space Sunshades Can Reduce the Magnitude of Climate Change Sunshade schemes are expected to reduce the solar radiation uniformly across the planet and hence could be represented by a reduction in solar constant. In the first climate modeling study (Govindasamy and Caldeira 2000), the solar constant is diminished by 1.8 % to balance the increased radiative forcing from a doubling of atmospheric CO2. The results indicate that, despite large differences in radiative forcing patterns (Fig. 91.1), large-scale sunshade schemes can markedly diminish regional and seasonal climate change from anthropogenic CO2 emissions (Fig. 91.2). This and other modeling studies which used solar constant reduction (Caldeira and Wood 2008; Govindasamy et al. 2003; Lunt et al. 2008) have essentially shown that the residual climate change in a world with sunshades, both globally and regionally, is much smaller than in a non-sunshade world with higher CO2 concentrations. It may be also possible to identify a level of sunlight reduction capable of meeting multiple targets, such as maintaining a stable mass balance of the Greenland ice sheet and cooling global climate, but without reducing global precipitation below preindustrial levels or exposing significant fractions of the Earth to “novel” climate conditions (Irvine et al. 2010).

Fig. 91.2 Annual mean surface temperature change in the case where atmospheric CO2 concentration is doubled (top left) and in the SRM case where atmospheric CO2 concentration is doubled and solar insolation is reduced by 1.8 % at the top of the atmosphere (bottom left). The right panels show regions where the temperature changes are significant at the 5 % level. Though solar forcing has a radiative forcing pattern that is vastly different from CO2 forcing

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Fig. 91.3 Zonally averaged annual mean temperature change in the case where atmospheric CO2 concentration is doubled (top panel) and in the SRM case where atmospheric CO2 concentration is doubled and solar insolation is reduced by 1.8 % at the top of the atmosphere (bottom panel). While warming is mitigated in the troposphere (height up to 10 km) in the SRM case, cooling of the stratosphere is not. Rather, cooling is enhanced in the stratosphere which could aggravate the depletion of ozone in the stratosphere. The results are obtained from an atmospheric general circulation model coupled to a mixed layer ocean model with prescribed ocean heat transport (Govindasamy and Caldeira 2000)

Space Sunshades Could Lead to Altered Regional Climates Some residual climate changes do remain as indicated in many modeling studies (Govindasamy et al. 2003; Lunt et al. 2008; Matthews and Caldeira 2007): a significant decrease in surface temperature and precipitation in the tropics, residual warming in the high latitudes, enhanced cooling in the stratosphere (Fig. 91.3), and incomplete restoration of sea ice. The stratospheric cooling caused by increased CO2 is not mitigated, and indeed the additional cooling due to reduced incident solar radiation could enhance stratospheric ozone depletion. Changes in climate variability and other climatic aspects resulting from reduced solar forcing are also examined by a few modeling studies. Compared to the natural climate, ä Fig. 91.2 (continued) (Fig. 91.1), a reduction in solar radiation by an appropriate amount in the SRM case mitigates the temperature response to CO2 forcing. The results are obtained from an atmospheric general circulation model coupled to a mixed layer ocean model with prescribed ocean heat transport (Govindasamy and Caldeira 2000)

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a uniform reduction in solar radiation may lead to reduced ENSO variability and increased North Atlantic overturning (Lunt et al. 2008). Simulations have also shown that large reduction in solar radiation could cause changes in ENSO and related climate teleconnection patterns (Braesicke et al. 2011).

Space Sunshades Can Rapidly Cool the Earth Sunshade schemes could cool the Earth rapidly to preindustrial levels within a decade (Matthews and Caldeira 2007). This decadal time scale is primarily dictated by the thermal inertia of the surface mixed layer ocean which comes to equilibrium within 15–20 years for any imposed climate perturbation. On longer time scales, feedbacks with deep ocean and heat storage in the deep ocean do become important, and it is possible that long-term climate change could be substantially different from the short-term change. However, in practice, time taken for the equilibration of mixed layer oceans is a reasonable indicator of the time scale for climate change. The first modeling study on the transient (as opposed to equilibrium) climate response to sunlight reduction (Matthews and Caldeira 2007) suggests that the climate system responds quickly to artificially reduced solar radiation; hence, there may be little cost if the deployment of SRM strategies is delayed until such time as “dangerous” climate change is imminent.

Space Sunshades Would Weaken the Global Water Cycle A zero change in global mean surface temperature in the high CO2 concentration and low solar radiation of the Earth would inevitably cause a reduction in global mean precipitation (Fig. 91.4) (Bala et al. 2008). This is because of differing vertical heating profiles of CO2 and solar forcing: CO2 forcing heats the atmosphere, but solar forcing primarily heats the surface. While the precipitation response per degree surface temperature change is the same for solar and CO2 forcing, it has been established that in the absence of surface warming, enhanced atmospheric CO2 suppresses precipitation by stabilizing the atmosphere, while the solar forcing has a much smaller effect on precipitation (Andrews et al. 2009; Bala et al. 2008, 2010a). Therefore, space sunshade schemes, if implemented to offset global mean surface warming, by offsetting only temperature-related precipitation change, would cause a weakening of the global water cycle (Bala et al. 2008). Alternatively, if the goal is to counteract changes in global mean precipitation, a residual surface warming will remain.

Space Sunshades Would Not Counteract the Direct Effects of CO2 While solar constant reduction may counter the radiative effects of CO2, it does not remove any direct effects of CO2 on natural ecosystems. On land, elevated CO2

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Fig. 91.4 Evolution of annual and global mean surface temperature (top panel) and precipitation in a simulation with present-day atmospheric CO2 concentration (control), a simulation with doubled CO2 concentration (doubled CO2), a simulation with solar radiation at the top of the atmosphere reduced by 1.8 % (solar), and a simulation with CO2 doubled and solar radiation reduced by 1.8 % (stabilized or SRM case). While the surface warming is mitigated in the stabilized climate relative to the control simulation (top panel), the hydrological cycle is weakened (bottom panel). The results are obtained from an atmospheric general circulation model coupled to a mixed layer ocean model with prescribed ocean heat transport (Bala et al. 2008)

stimulates uptake by terrestrial vegetation and hence enhances vegetation and soil carbon stocks through CO2 fertilization effect. Modeling studies have shown that sunlight reduction would tend to limit changes in vegetation distribution caused by radiatively induced climate warming but would not prevent fertilization-induced changes in terrestrial plant productivity or carbon stocks (Govindasamy et al. 2002). In the ocean, acidification caused by elevated CO2, which will likely be detrimental to marine ecosystems, is not prevented by reduced solar radiation (Bengtsson 2006). However, due to the strong coupling between climate and the

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carbon cycle, reduced solar energy could marginally affect the carbon cycle through indirect means. For instance, modeling studies have shown that reduction in solar radiation could indirectly affect ocean chemistry (Matthews et al. 2009) by redistributing carbon emissions among atmosphere, land, and ocean reservoirs with enhanced carbon stocks over land.

Space Sunshades Do Not Mitigate CO2 Physiological Effect In addition to trapping longwave radiation, increasing atmospheric CO2 affects the climate system by its effect on plant stomata. Plant stomata open less widely under elevated CO2 concentrations, leading to reduced plant transpiration. This effect, referred to as CO2 physiological forcing, enhances the CO2 radiative warming by about 10 % at the global scale and can account for up to 30 % of the total warming at regional scales (Boucher et al. 2009; Cao et al. 2010). More importantly, the CO2 physiological forcing has significant implications on the global hydrological cycle since it could potentially lead to increase in runoff (Betts et al. 2007; Cao et al. 2010; Gedney et al. 2006). Reduction in sunlight by space sunshades do not counteract the effect of CO2 physiological forcing, since they only act on the radiative budget of the planet.

Space Sunshades May Need to Be Maintained for Multiple Centuries It is now widely recognized that the atmospheric lifetime of anthropogenic CO2 is extremely long. While more than half of emitted CO2 is absorbed by natural carbon sinks on land and in the surface ocean, additional permanent removal requires transport of carbon to the deep ocean, which occurs slowly over many centuries. More than two thirds of the peak atmospheric CO2 will likely remain in the atmosphere after several centuries and on the order of one third of the peak atmospheric CO2 may still be present after 10,000 years (Eby et al. 2009). Therefore, space sunshades, if implemented, may need to be maintained for a long time (may be multiple centuries depending on climate policy) until atmospheric CO2 returns to current or preindustrial levels.

Failure of Sunshades Can Lead to Catastrophic Climate Change Space sunshade schemes, if implemented at large scales, could also subject the planet to the problem of “termination effect.” The termination effect refers to the fact that a sudden halt or failure of the scheme could lead to a rapid warming. The failure of a space sunshade scheme could subject the Earth to extremely rapid warming with the rate of warming many times that of the current warming (Matthews and Caldeira 2007; Wigley 2006). While a non-sunshade world would warm slowly with the slowly increasing CO2, the sunshade-failed scenario

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instantaneously imposes a large climate forcing at the point of failure, and the climate system responds to this larger forcing on a time scale of 10–20 years (the time scale of the mixed layer ocean) with larger warming rates. Furthermore, compared to a climate with higher temperature and elevated CO2 level, much more carbon would be stored in the oceans and land in a climate with low solar irradiance, low temperature, and high CO2. In the case of a halt or failure of the sunshade scheme, a sudden warming would cause the carbon stored in the land and ocean reservoir to be released into the atmosphere, triggering a further warming that is much greater and faster than the climate in the absence of space sunshades (Matthews and Caldeira 2007).

Discussion Space-based SRM schemes aim to counteract greenhouse-gas warming by reducing the incoming solar radiation uniformly across the globe. Many modeling studies have simulated the effects of space sunshades by reducing the solar constant: approximately 2 % reduction is required to counter climate change from a doubling of CO2. The climate with high greenhouse-gas concentrations and sunshades would be more similar to the climate with “natural” greenhouse-gas concentrations than to the climate with high greenhouse-gas concentrations and no space sunshades. Space sunshades could also rapidly cool the climate system (Matthews and Caldeira 2007). SRM schemes have been often characterized as imperfect because they act on effects of climate change rather than the root cause of climate change (Royal Society Report 2009). One issue common to all SRM schemes is that it may not be feasible to simultaneously restore all climatic fields (e.g., temperature and precipitation) to the natural state, even in terms of global mean values; and it may not be possible to simultaneously restore climate change in all regions, even for a single climate field. For instance, modeling studies have shown that the residual temperature changes are much smaller in an SRM world than without the SRM schemes, but all models show large residual changes in precipitation (Ricke et al. 2010). In contrast to sunshades which are likely to reduce the solar irradiance uniformly across the globe, surface-based albedo enhancements such as brightening the marine clouds or whitening the urban roofs impose heterogeneous reduction in solar radiation absorption: albedo enhancement and the consequent reduction in solar radiation absorption would occur only over either land or oceans. Recent modeling studies (Bala and Nag 2012; Bala et al. 2010b) have shown large residual hydrological changes over land for these schemes as a result of the heterogeneity in applied forcing. On both the global and regional scales, there would be a trade-off between climate fields such as surface temperature, precipitation, sea ice, and monsoon for any SRM scheme. What might be preferred is an SRM approach and/or a combination of different SRM schemes that would yield optimal solution to

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these trade-offs. Steps have been taken in this exploration using climate models (Ban-Weiss and Caldeira 2010; Irvine et al. 2010; Rasch 2010). Furthermore, to have a robust assessment of climate impact from SRM methods, a standard modeling experiment protocol with the same SRM forcing applied to multiple climate models is needed. This effort has been initiated for the modeling of climate effects from stratospheric aerosol injections (Kravitz et al. 2011). Finally, but not the least important, the possibility of SRM is by no means an excuse for continued fossil fuel emissions. A combined emission mitigation and geoengineering strategy is what we might want to seek to avoid dangerous climate change and reduce our dependence on fossil fuel emissions (Wigley 2006).

References Akbari H, Menon S, Rosenfeld A (2009) Global cooling: increasing world-wide urban albedos to offset CO2. Clim Change 94(3–4):275–286 Andrews T, Forster PM, Gregory JM (2009) A surface energy perspective on climate change. J Climate 22:2557–2570 Angel R (2006) Feasibility of cooling the Earth with a cloud of small spacecraft near the inner Lagrange point (L1). Proc Natl Acad Sci USA 103(46):17184–17189 Bala G, Nag B (2011) Albedo enhancement over land to counteract global warming: impacts on hydrological cycle. Clim Dyn 39:1527–1542 Bala G, Duffy PB, Taylor KE (2008) Impact of geoengineering schemes on the global hydrological cycle. Proc Natl Acad Sci USA 105(22):7664–7669 Bala G, Caldeira K, Nemani R (2010a) Fast versus slow response in climate change: implications for the global hydrological cycle. Clim Dyn 35(2–3):423–434 Bala G, Caldeira K, Nemani R, Cao L, Ban-Weiss G, Shin HJ (2010b) Albedo enhancement of marine clouds to counteract global warming: impacts on the hydrological cycle. Clim Dyn. doi:10.1007/s00382-010-0868-1 Ban-Weiss GA, Caldeira K (2010) Geoengineering as an optimization problem. Environ Res Lett 5(3):034009 Bengtsson L (2006) Geo-engineering to confine climate change: is it at all feasible? Clim Change 77(3–4):229–234 Betts RA et al (2007) Projected increase in continental runoff due to plant responses to increasing carbon dioxide. Nature 448:1037–1041 Boucher O, Jones A, Betts RA (2009) Climate response to the physiological impact of carbon dioxide on plants in the Met Office Unified Model HadCM3. Clim Dyn 32(2–3):237–249 Braesicke P, Morgenstern O, Pyle J (2011) Might dimming the sun change atmospheric ENSO teleconnections as we know them? Atmos Sci Lett 12(2):184–188 Budyko MI (1977) Climate Changes. American Geophysical Union, Washington DC, English translation of 1974 Russian volume, 244 pp Caldeira K, Wood L (2008) Global and Arctic climate engineering: numerical model studies. Philos Trans R Soc A 366(1882):4039–4056 Cao L, Bala G, Caldeira K, Nemani R, Ban-Weiss G (2010) Importance of carbon dioxide physiological forcing to future climate change. Proc Natl Acad Sci USA 107(21): 9513–9518 Crutzen PJ (2006) Albedo enhancement by stratospheric sulfur injections: a contribution to resolve a policy dilemma? Clim Change 77(3–4):211–219 Early JT (1989) The space based solar shield to offset greenhouse effect. J Br Interplanet Soc 42:567–569

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Eby M, Zickfeld K, Montenegro A, Archer D, Meissner KJ, Weaver AJ (2009) Lifetime of anthropogenic climate change: millennial time scales of potential CO2 and surface temperature perturbations. J Climate 22(10):2501–2511 Evans JRG, Stride EPJ, Edirisinghe MJ, Andrews DJ, Simons RR (2010) Can oceanic foams limit global warming? Climate Res 42(2):155–160 Gedney N, Cox PM, Betts RA, Boucher O, Huntingford C, Stott PA (2006) Detection of a direct carbon dioxide effect in continental river runoff records. Nature 439(7078):835–838 Govindasamy B, Caldeira K (2000) Geoengineering Earth’s radiation balance to mitigate CO2-induced climate change. Geophys Res Lett 27(14):2141–2144 Govindasamy B, Thompson S, Duffy PB, Caldeira K, Delire C (2002) Impact of geoengineering schemes on the terrestrial biosphere. Geophys Res Lett 29(22):2061. doi:2010.1029/ 2002GL015911 Govindasamy B, Caldeira K, Duffy PB (2003) Geoengineering Earth’s radiation balance to mitigate climate change from a quadrupling of CO2. Global Planet Change 37(1–2):157–168 IPCC (2007) Climate change 2007: the physical science basis. Cambridge University Press, Cambridge, UK/New York Irvine PJ, Ridgwell A, Lunt DJ (2010) Assessing the regional disparities in geoengineering impacts. Geophys Res Lett 37, L18702 Keith DW (2001) Geoengineering. Nature 409(6818):420 Kravitz B, Robock A, Boucher O, Schmidt H, Taylor KE, Stenchikov G, Schulz M (2011) The Geoengineering Model Intercomparison Project (GeoMIP). Atmos Sci Lett 12(2):162–167 Latham J (1990) Control of global warming. Nature 347(6291):339–340 Latham J, Rasch P, Chen CC, Kettles L, Gadian A, Gettelman A, Morrison H, Bower K, Choularton T (2008) Global temperature stabilization via controlled albedo enhancement of low-level maritime clouds. Philos Trans R Soc A 366(1882):3969–3987 Lunt DJ, Ridgwell A, Valdes PJ, Seale A (2008) “Sunshade world”: a fully coupled GCM evaluation of the climatic impacts of geoengineering. Geophys Res Lett 35(12), L12710. doi:12710.11029/12008GL033674 Matthews HD, Caldeira K (2007) Transient climate-carbon simulations of planetary geoengineering. Proc Natl Acad Sci USA 104(24):9949–9954 Matthews HD, Cao L, Caldeira K (2009) Sensitivity of ocean acidification to geoengineered climate stabilization. Geophys Res Lett 36, L10706 McInnes CR (2010) Space-based geoengineering: challenges and requirements. Proc Inst Mech Eng Part C-J Mech Eng Sci 224(C3):571–580 NAS (1992) Policy implications of greenhouse warming: mitigation, adaptation and the science base. In: National Academy of Sciences (ed) National Academy Press, Washington DC, Chap. 28 (Geoengineering), pp 433–464 Pearson J, Oldson J, Levin E (2006) Earth rings for planetary environment control. Acta Astronaut 58(1):44–57 Rasch PJ (2010) Technical fixes and climate change: optimizing for risks and consequences. Environ Res Lett 5(3):031001 Ricke KL, Morgan G, Allen MR (2010) Regional climate response to solar-radiation management. Nat Geosci 3(8):537–541 Royal Society Report (2009) Geoengineering the climate: science, governance and uncertainty Rep. London Seifritz W (1989) Mirrors to halt global warming. Nature 340(6235):603 Struck C (2007) The feasibility of shading the greenhouse with dust clouds at the stable lunar Lagrange points. J Br Interplanet Soc 60(3):82–89 Wigley TML (2006) A combined mitigation/geoengineering approach to climate stabilization. Science 314(5798):452–454

Enhancing the Ocean’s Role in CO2 Mitigation

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Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Ocean’s Natural Role in CO2 Mitigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ways of Increasing the Ocean’s Natural CO2 Mitigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Physical Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chemical Enhancement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Biological Enhancement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cross-References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

The equivalent of about 1/4 of annual anthropogenic CO2 emissions is absorbed and stored by the ocean, and the sea plays the primary role in naturally removing excess atmospheric CO2 on geologic timescales. Ways of safely enhancing or augmenting this carbon uptake and storage therefore have the potential to contribute significantly to atmospheric CO2 stabilization efforts. Various physical, chemical, biological, and hybrid strategies of increasing ocean CO2 uptake or reducing CO2 leakage have been proposed. Further research is needed to better determine the full range of options and their costs, benefits, impacts, and overall desirability as CO2 mitigation methods. Keywords

Carbon storage • CO2 • Marine carbon chemistry • Ocean • Ocean acidification • Seawater

G.H. Rau Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_54, # Springer Science+Business Media Dordrecht 2014

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Definition Finding ways of safely increasing or augmenting the ocean’s absorption and storage of carbon could significantly contribute to stabilization of atmospheric CO2 concentrations.

The Ocean’s Natural Role in CO2 Mitigation Of the approximately 30 Gt/year (1 gigatonne ¼ 109 metric tons) of CO2 currently emitted to the atmosphere by human activity, the ocean in net consumes the equivalent of about 7 Gt/year of these emissions. These numbers are, however, dwarfed by the annual gross amounts of CO2 naturally taken up and released by the ocean, which are in excess of 300 Gt CO2/year (90 Gt C/year, Fig. 92.1). Furthermore, the carbon content in the ocean is about 50 times that of the atmosphere, with the majority of ocean carbon in a form (HCO3) that can, through equilibrium reactions, interact with atmospheric CO2. Marine chemical, biological, and physical processes that naturally affect ocean CO2 gain and loss therefore intimately influence the natural carbon content of the atmosphere. Indeed, ocean chemistry together with carbonate and silicate mineral weathering is the primary mechanism that naturally moderates and consumes excess atmospheric CO2 on 760

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geologic timescales (Archer et al. 2009). The ocean is therefore a logical place to explore means of enhancing atmospheric and anthropogenic carbon uptake and/or sequestration in efforts to stabilize atmospheric CO2 concentrations. It is the possibility of modifying such global processes (often only relatively slightly) that is the basis for many of the ocean-based CO2 mitigation ideas thus far proposed.

Ways of Increasing the Ocean’s Natural CO2 Mitigation Physical Methods The surface and subsurface ocean exchange mass and dissolved constituents through diffusive, advective, and sedimentary processes. For example, globalscale overturning of the ocean driven by vertical temperature and/or salt density gradients, principally at high latitudes (thermohaline circulation), subducts surface water into the deep ocean and in turn forces deep water to the surface elsewhere on timescales of about 1,500 years. This residence in the deep ocean and away from contact with the atmosphere presents an environment in which excess carbon could be at least temporarily sequestered. Marchetti (1977) first proposed injecting waste CO2 captured from land-based point sources into relatively salty, dense Mediterranean bottom water prior to its spilling into the intermediate and deep waters of the Atlantic Ocean, thus effecting relatively long-term sequestration from the atmosphere. Subsequent research has explored various methods of injecting CO2 into the subsurface ocean and has investigated the locations and depths that might prove most effective (Caldeira et al. 2005). A major concern with CO2 injection into the ocean is acidification; injecting concentrated CO2 into seawater forms, via hydration mechanisms, carbonic acid that depresses pH, which can have significant impacts on marine biota (Caldeira et al. 2005). A possible solution is to “package” CO2 in a form that does not readily react with or exchange with seawater. Such forms might include high-density, supercritical CO2, CO2 clathrates, and CO2 emulsions that would reside on or near the ocean bottom for periods potentially far in excess of deep ocean water residence times. Additionally, injection of CO2 into geologic strata below the ocean floor also presents long-term sequestration potential (Schrag 2009) as, for example, currently practiced at the Sleipner facility in the North Sea. A major hurdle for any approach that uses molecular CO2 as the storage medium is the very energetically and financially costly process of forming concentrated molecular CO2 from more dilute, impure waste sources (Rochelle 2009). A second way that ocean physics can influence atmospheric CO2 is through the vertical advection or upwelling of nutrient-rich subsurface water to the ocean’s surface. Nutrients (e.g., P, N, and Si compounds) often limit marine photosynthetic biomass production and subsequent sinking (pumping) of carbon into the deep ocean and sediments (see “Biological Enhancement” section below). Methods of increasing nutrient delivery via upwelling have been proposed, harnessing wave or thermal energy to lift nutrient-rich water to the ocean surface (e.g., Lovelock and Rapley 2007).

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Concerns about the effectiveness of such approaches include the lifting and surface degassing of elevated CO2 that normally resides in subsurface water, thus potentially countering net CO2 sequestration from the atmosphere afforded by enhanced marine photosynthesis and subsequent biomass sequestration in the deep ocean.

Chemical Enhancement CO2 readily reacts with chemical bases such as hydroxides and carbonates via these reactions: OH þ CO2 ! HCO3 

(92.1)

CO3 2 þ CO2 þ H2 O ! 2HCO3 

(92.2)

Hydroxide and carbonate ions are present in elevated concentrations in seawater, contributing to the ocean’s natural alkalinity and carbon retention. Therefore, methods that increase the concentration of such ions will increase the ocean’s ability to absorb and store atmospheric CO2 primarily in the form of bicarbonate ions. Indeed, Kheshgi (1995) first proposed adding Ca(OH)2 to seawater to enhance air CO2 absorption and sequestration, showing that 1.8 mol of CO2 would be absorbed per mole of Ca(OH)2 added. However, the formation of Ca(OH)2 from CaCO3 (calcination of limestone) is energy intensive, and if fossil energy is used, the resulting CO2 generated is almost as large as the CO2 ultimately absorbed by a Ca(OH)2-enriched ocean. A possible way to reduce this carbon footprint is to employ capture and sequestration of these CO2 emissions (Geological sequestration chapter) or to use solar thermal (Nikulshina et al. 2006) or electrochemical (Rau 2008) calcination. Further concerns with this approach include the cost, safety, and ecological impact of transporting and distributing concentrated hydroxide in the ocean. It is also possible to absorb CO2 and dissolve limestone directly by contacting the latter with seawater and concentrated waste CO2, thus accelerating the natural absorption of CO2 by the carbonate weathering reaction (Rau and Caldeira 1999): CO2 þ H2 O þ CaCO3ðsÞ ! CaðHCO3 Þ2ðaqÞ Despite ultimately adding to the already supersaturated state of calcium carbonate in seawater, tests have shown that the dissolved Ca(HCO3)2 formed is resistant to abiotic precipitation as CaCO3 (Rau 2011), being strongly inhibited by other ions naturally present in seawater. This does not preclude such carbon loss by biological precipitation of CaCO3 (e.g., shell formation), but relative to the existing seawater carbon pool, such losses are significant only on geologic timescales (residence time of Ca2+ in seawater ffi 1 Myrs). Due to seawater demands, the process is best suited to mitigating coastal CO2 point sources where limestone reserves and seawater are in close proximity.

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An alternative use of CaCO3 for marine-based CO2 mitigation is to add limestone directly to seawater (Harvey 2008). While the surface ocean is supersaturated in CaCO3, subsurface waters are undersaturated and therefore corrosive to CaCO3. Sinking additional CaCO3 particles into the ocean will thus lead to their dissolution and hence additional alkalinity formation at depth, the amount depending on the size of the particles and the sinking path length offered by the undersaturated waters at a particular location. The resulting alkalinity addition to seawater increases the absorption capacity of CO2 (reactions 92.1 and 92.2), but to have an effect on atmospheric CO2, such water must be advected to the ocean surface and have contact with the atmosphere. Timescales for such vertical advection can range from 100 to >1,000 years depending on depth, location, and ocean physics, i.e., the potential effect on air CO2 is not immediate. One concern of this approach is the unknown ecological consequences of adding large volumes of mineral particles to the ocean. Similarly, the contacting of silicate minerals with seawater has been considered Koehler et al. (2013) as a means of accelerating natural silicate mineral weathering reactions, e.g., 4CO2 þ 4H2 O þ Mg2 SiO4ðsÞ ! 2MgðHCO3 Þ2ðaqÞ þ H4 SiO4ðaqÞ However, the rates of such reactions are orders of magnitude lower than that of carbonate weathering, thus requiring much larger masses of finer particles to potentially have a near-term impact on atmospheric CO2. In order to speed up mineral weathering to effect air CO2 capture, conversion, and storage by the ocean, House et al. (2007) and Rau et al. (2013) proposed seawater-based electrochemical dissolution methods powered by renewable electricity. Concerns with all of the preceding mineral or mineral product additions to seawater include the environmental impact of increased mineral extraction, processing, and transportation. The quantity, impact, and fate of unreacted impurities in the minerals would need to be considered, as well as consequences of adding the resulting alkalinity to the ocean. Some assurance might be found in the fact that mineral weathering is a natural process within the hydrologic cycle that delivers Gts of solutes to the ocean annually (e.g., Fig. 92.1), and many of these ionic constituents are essential to marine life. In this regard, another potential environmental benefit is the elevation of calcium carbonate saturation state in seawater that results from accelerated mineral weathering. Recent evidence points to the depression of this saturation index as the central reason whereby ongoing ocean acidification reduces marine biological shell formation (Andersson et al. 2011). Accelerating certain forms of mineral weathering therefore not only would reduce pre- or post-emissions CO2 but could help offset the chemical and hence biological effects of CO2-induced ocean acidity. Rather than the ocean consuming and storing CO2 in molecular or other inorganic forms, an alternative marine CO2 mitigation strategy is to extract CO2 from seawater. For example, the electrochemical stripping of CO2 from seawater has been demonstrated as a potential precursor to synthetic hydrocarbon fuel production (Eisaman et al. 2012). While such carbon use could at best only approach

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carbon neutrality, non-emitting uses or storage of the extracted CO2 would leave the seawater undersaturated in CO2 and elevated in pH. This would force passive net CO2 removal from air to ocean and, prior to air/sea equilibrium, reduce ocean acidification.

Biological Enhancement Another way to effect net air/ocean CO2 removal is via photosynthesis, forming organic compounds (biomass), e.g., nCO2 þ nH2 O þ solar energy ! ðCH2 OÞn þ nO2 keeping in mind that respiration can reverse the process: ðCH2 OÞn þ nO2 ! nCO2 þ nH2 O þ energy Any sustained global increase in photosynthesis relative to respiration therefore produces a net atmospheric CO2 sink. Indeed, photosynthetic production of biomass in the surface ocean, coupled with the sinking of some of this biomass into the subsurface ocean, forms a natural “biological pump” of carbon from the atmosphere to the deep ocean and sediments. Since photosynthesis in large areas of the ocean is iron limited (Martin 1991), considerable research has focused on the possibility of adding soluble iron to the ocean to enhance the biological carbon pump. Mesoscale experiments have indeed shown that photosynthesis and CO2 drawdown can be stimulated by iron addition (Lampitt et al. 2008). However, the timescales and net atmospheric CO2 benefit attained by such addition are not easily measured due to difficulties in tracking net carbon export over large horizontal, vertical, and temporal scales. The addition of macronutrients such as nitrate and phosphate can also in theory enhance marine photosynthesis and hence carbon pumping in regions where these nutrients are limited (Matear and Elliot 2004). The major issues surrounding the use of ocean fertilization to stimulate the marine carbon pump include (1) selective benefit or suppression of certain marine species in response to fertilization and hence potential alteration of marine community structure and function, (2) uncertainties in the quantities of carbon removed per unit nutrient added and residence times of such carbon, and (3) the chemical and biological consequences of increased organic matter loading and hence respiration (O2 consumption and CO2 generation) in subsurface waters and sediments. Further research is needed to better understand the environmental costs, benefits, and desirability of ocean fertilization as a CO2 mitigation tool. Conversely, it might be possible to reduce respiration in the ocean by preserving carbon in more recalcitrant, organic forms, thus reducing CO2 production within the ocean and therefore reducing the flux of CO2 from the ocean to the atmosphere. Possibilities include manipulating the composition, size, or sinking rate of organic

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matter to reduce water column respiration and increase the usually very small fraction of organic carbon ultimately buried and sequestered in sediments (Lam et al. 2011). Alternatively, qualitative modification of a portion of the ocean’s massive pool of dissolved organic matter (700 Gt C) could render it more resistant to respiration and hence increase its large carbon sequestration potential (Jiao et al. 2011). In addition, exporting land biomass to ocean sediments, thereby reducing its respiration and CO2 release to the atmosphere, has been proposed as a method for increasing net ocean carbon sequestration. For example, packaging, transporting, and sinking land crop residue onto ocean sediments would provide effective carbon storage away from the atmosphere, especially in ocean regions where sediment respiration is already impeded by low oxygen concentrations (Strand and Benford 2009). The scheme simply enhances the natural “carbon pump” of photosynthetic removal of air CO2 by land plants, the riverine transport of a fraction of the resulting non-respired biomass and soil organic matter to the ocean, and the subsequent sequestration of this carbon in ocean sediments (Fig. 92.1). Concerns about this approach include (1) loss of organic carbon and nutrient inputs to soils, potentially requiring greater fertilizer amendments and altering soil properties; (2) the cost of packaging, ballasting, transporting, and sinking crop residues; and (3) impacts to deep ocean and benthic ecosystems and biogeochemistry.

Conclusions The ocean currently plays and will play a major role in moderating and ultimately reversing the human-caused increase in atmospheric CO2. Various ways of enhancing and accelerating this role have been considered, and at this early stage, additional ideas are likely to emerge. Further research is needed in order to better determine the capacity and effectiveness of such methods, and their environmental, monetary, and societal cost/benefit.

Cross-References ▶ Carbon Sequestration in Soil and Vegetation and Greenhouse Gases Emissions Reduction ▶ Ecological Carbon Sequestration in the Oceans and Climate Change ▶ Ocean Acidification and Oceanic Carbon Cycling

References Andersson AJ, Mackenzie FT, Gattuso J-P (2011) Effects of ocean acidification on benthic processes, organisms, and ecosystems. In: Gattuso J-P, Hansson L (eds) Ocean acidification. Oxford University Press, Oxford

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Archer D et al (2009) Atmospheric lifetime of fossil fuel carbon dioxide. Annu Rev Earth Planet Sci 3:117–134 Caldeira K et al (2005) Ocean storage. In: Metz B et al (eds) IPCC special report on carbon dioxide capture and storage. Prepared by Working Group III of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge Eisaman MD et al (2012) CO2 extraction from seawater using bipolar membrane electrodialysis. Energy Environ Sci 5:7346–7352 Harvey LDD (2008) Mitigating the atmospheric CO2 increase and ocean acidification by adding limestone powder to upwelling regions. J Geophys Res Oceans 113. doi:10.1029/ 2007JC004373 House KZ et al (2007) Electrochemical acceleration of chemical weathering as an energetically feasible approach to mitigating anthropogenic climate change. Environ Sci Technol 41:8464–8470 Jiao NZ et al (2011) The microbial carbon pump and the oceanic recalcitrant dissolved organic matter pool. Nat Rev Microbiol 9. doi:10.1038/nrmicro2386-c5 Kheshgi HS (1995) Sequestering atmospheric carbon dioxide by increasing ocean alkalinity. Energy 20:915–922 Koehler et al (2013) Geoengineering impact of open ocean dissolution of olivine on atmospheric CO2, surface ocean pH and marine biology. Environ Res Lett 8, 14,009. doi:10.1088/17489326/8/1/014009 Lam PJ et al (2011) The dynamic ocean biological pump: insights from a global compilation of particulate organic carbon, CaCO3, and opal concentration profiles from the mesopelagic. Global Biogeochem Cycles 25, GB3009. doi:10.1029/2010GB003868 Lampitt RS et al (2008) Ocean fertilization: a potential means of geoengineering? Philos Trans Royal Soc A 366:3919–3945 Lovelock JE, Rapley CG (2007) Ocean pipes could help the Earth to cure itself. Nature 449:403 Marchetti C (1977) On geoengineering and the CO2 problem. Climatic Change 1:59–68 Martin JH (1991) Iron, Liebig’s law, and the greenhouse. Oceanography 4:52–55 Matear RJ, Elliott B (2004) Enhancement of oceanic uptake of anthropogenic CO2 by macronutrient fertilization. J Geophys Res Oceans 109, C04001. doi:10.1029/2000JC000321 Nikulshina V et al (2006) CO2 capture from air and co-production of H2 via the Ca(OH)2-CaCO3 cycle using concentrated solar power – thermodynamic analysis. Energy 31:1715–1725 Rau GH (2008) Electrochemical splitting of calcium carbonate to increase solution alkalinity: implications for mitigation of carbon dioxide and ocean acidity. Environ Sci Tech 42:8935–8940 Rau GH (2011) CO2 mitigation via capture and chemical conversion in seawater. Environ Sci Technol 45:1088–1092 Rau GH et al (2013) Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production. Proc Nat Acad Sci 110:10095–10100 Rau GH, Caldeira K (1999) Enhanced carbonate dissolution: a means of sequestering waste CO2 as ocean bicarbonate. Energy Convers Manag 40:1803–1813 Rochelle GT (2009) Amine scrubbing for CO2 capture. Science 325:1652–1654 Schrag DP (2009) Storage of carbon dioxide in offshore sediments. Science 325:1658–1659 Strand SE, Benford G (2009) Ocean sequestration of crop residue carbon: recycling fossil fuel carbon back to deep sediments. Environ Sci Technol 43:1000–1007

Additional Recommended Reading Gattuso J-P, Hansson L (2011) Ocean acidification. Oxford University Press, Oxford Stephens JC, Keith DW (2008) Assessing geochemical carbon management. Clim Change 90:217–242 Zeebe RE, Wolf-Gladrow DA (2001) CO2 in seawater: equilibrium, kinetics, isotopes. Elsevier, Amsterdam

Part X Social Aspects of Global Change Deborah S. Rogers

Social Aspects of Global Change, Introduction

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Deborah S. Rogers

It is not possible to address the drivers, impacts, or responses related to global environmental change without understanding the social dimensions. We are living in the Anthropocene: a time when the primary factors affecting the environment and causing change are human choices and activities. The impacts of global environmental change fall not only on the geosphere and ecosystems of the Earth but also on human societies. Virtually every possibility for responding to global environmental change – slowing, stopping, mitigating, reversing, or adapting – impinges on the social realm. Some of the most productive research on global environmental change, particularly studies which attempt to predict trajectories, impacts, and the consequences of possible responses, involves complex systems modeling – and human activities are a major part of such models. All meaningful policy options concerning global environmental change revolve around societal choices and their projected impacts. Yet to date, much of the study of global environmental change has been viewed as the prerogative of the natural sciences. While social scientists are sometimes brought in on certain defined questions, the big-picture framing of issues and questions has been the work of natural scientists, from atmospheric and oceanographic specialists through environmental chemists and toxicologists to ecologists. I acknowledge and laud the foresight and willingness of natural scientists to force these critical issues to the attention of the public and decision-makers, often at great personal and professional risk. However, social scientists must be brought to the table as full partners in the framing and development of the research agenda, as well as in conducting and interpreting studies and developing policy recommendations.

D.S. Rogers Institute for Research in the Social Sciences (IRiSS), Stanford University, Stanford, CA, USA e-mail: [email protected]; [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_55, # Springer Science+Business Media Dordrecht 2014

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This is absolutely crucial, if we are to have any hope of understanding how to work our way out of the current crisis. We must include the full range of social sciences and probably the humanities as well; it is not sufficient to include only orthodox economists who tend to construct models based on business-as-usual, profit-maximizing assumptions with a few “green” goals tacked on. Another crucial reason for bringing the social sciences to the table is an ethical and normative one: the goals of research and policy debates regarding global environmental change and the shift towards sustainability cannot be set solely by scientists or even science-policy specialists. Rather, those goals must reflect the wishes and values of societies, including minority communities, if they are to be broadly accepted and implemented by societies. Of course, such goals must be set within the reality of what science and technical research tells us is possible, but the imposition of top-down goals by research and policy elites is both unrealistic and unethical. Social scientists can help ascertain the wishes and values of societies and communities, particularly as they are understood through participatory action research and participatory assessments (see the global Equity & Sustainability Field Hearings as described by Rogers and Bala´zs 2013). The purpose of this book section entitled “Social Aspects of Global Change” is to provide an overview of the kinds of topics and perspectives that social scientists bring to the table when approaching the subject of global environmental change. The astute reader will notice some big differences between the ways that social scientists approach topics, compared to those of natural scientists. Social scientists address the ethical and normative dimensions of problems head on, rather than attempting to purge their research of “bias” by framing questions as purely objective. Social scientists are dealing with a subject that is more complex and difficult to quantify – human nature and choices – and thus there are fewer widely accepted factual data and more disagreement among researchers. In the absence of widely accepted approaches, it often becomes necessary to outline the theoretical basis underlying each analysis. Many (but certainly not all) social scientists are skeptical about the use of quantitative models to analyze social questions. Articles and books by social scientists tend to be far wordier because of the need to explain theoretical frameworks or insert parenthetical explanations, caveats, and other hedges when data and conclusions are not simple or definitive. We certainly do not have a global scientific consensus on the human dimensions of global environmental change analogous to that developed by the IPCC (Intergovernmental Panel on Climate Change) on the physical dimensions, although an attempt to distill a set of accepted social sciences findings has been proposed by, for example, the International Human Dimensions Programme on Global Change. You will not, therefore, find a list of definitive answers in this section. But you will find a good overview of many of the major questions and current understandings. It would be a mistake to assume these chapters are simply opinion pieces. The chapters of this section bring to our attention crucial social aspects based on a vast body of research and thinking in many fields.

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Clark’s chapter on “▶ Defining and Measuring Human Well-Being” sets the stage for understanding the relationship between the environment and human societies. He outlines various approaches to the concept of human well-being, suggests that the idea of “sustainable human development” can help resolve the apparent tension between poverty reduction and environmental conservation and sustainability, and calls for a more comprehensive account of human well-being in order to bridge the gap between the intangible (happiness, rights, capabilities) and tangible (meeting needs, income, resources) aspects of well-being. Three chapters consider the ethical dimensions of the impacts of global environmental change on humans. Mazor’s chapter on “▶ Environmental Ethics” introduces the reader to the topic through two central questions: how should we determine the right level of overall degradation of some common global natural resource, and what is the fair way to allocate the rights to damage that resource? Wagner’s chapter on “▶ Human Rights, Rights of the Earth, and Global Change” asserts that human rights can protect both people and the environment on which we depend, including the rights to life, health, and culture; to water and a healthy environment; to indigenous cultural survival; and to participate in decision-making, access relevant information, and fair judicial and legislative remedies. Luttermann’s chapter on “▶ Linguistic and Cultural Homogenization in the Face of Global Change, a Subarctic Example” raises ethical concerns about the impacts of global change, both environmental and social, on the diversity of human cultures. She illustrates her concerns with a concrete example of subarctic indigenous peoples in Canada, who have experienced major cultural and socioeconomic change due to extensive hydroelectric development, with little consultation about their needs and aspirations. A pair of related chapters by Wisner and Fordham delve into the practical and ethical aspects of risk, vulnerability, and response – these are urgent questions as societies experience worsening and increasingly frequent environment-related disasters. Their chapter on “▶ Vulnerability and Capacity” explains that, while triggered by natural hazards, disasters are never truly “natural” but are a result of hazard events interacting with people who are prepared or unprepared and who have access to the resources to reduce risk or are deprived of such resources. Their chapter on “▶ Managing Risk and Responding to the Unknown” tackles the complex problems of “disaster management” and “disaster risk reduction,” concluding that global implementation of the latter has not had the desired results due to problems with governance structures, availability of financial resources, and power dynamics between local communities and the regional and national governments and NGOs that support or partner with them. Meuleman’s chapter on “▶ Governance Frameworks” assesses the strengths and weaknesses of three main governance approaches: hierarchical (emphasis on top-down thinking and hegemony), network (emphasis on pluralism, dialogue, and partnerships), and market (emphasis on individualism and autonomy). He concludes that governance frameworks should be tailor-made to specific problems and situations and be implemented at multiple levels and scales.

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Bluffstone’s chapter on “▶ Pollution and Pollution Control Through an Economic Lens” examines the economic incentives (in our current neoliberal economic system) to degrade environmental resources and free ride off those who protect them. He proposes four general solutions within that system: elimination of environmentally harmful subsidies, technology standards, performance standards, and incentive-based or economic instruments such as cap-and-trade or various fees and taxes on pollution or damaging products. Finally, the book section includes four chapters that address mechanisms of societal change that could be effective in responding to global environmental change. Blackmore’s chapter on “▶ Knowledge, Learning, and Societal Change for Sustainability” observes that in complex situations such as management of scarce natural resources, stakeholders need to develop shared knowledge and understanding and harmonize their actions. She points out that learning about sustainability does not necessarily lead to action because the abilities of individuals and groups to act are often constrained by other societal factors. Ross, Richerson, and Rogers’ chapter on “▶ Mechanisms of Cultural Change and the Transition to Sustainability” provides a contrasting model, outlining the various mechanisms of evolutionary cultural change, including guided variation (choices made from among alternatives), biasing forces (such as conformity or emulating success or prestige), and differential success (variation and natural selection). They describe how we might harness the mechanisms of cultural evolution to favor ecologically and socially beneficial change, primarily through altering the referential time frame, status or prestige outcomes, institutional incentives and constraints, and political and economic interests that are served by certain behaviors or beliefs. Rogers’ chapter on “▶ Socioeconomic Equity and Sustainability” proposes that socioeconomic inequality is one of the primary drivers of environmental degradation, even while that damage is one of the main ways in which socioeconomic inequality is manifested. She argues that socioeconomic inequality is a major barrier that must be addressed before we can make progress on solutions to global environmental problems and transitions towards sustainability. Last but not least, Brulle’s chapter on “▶ Engaging Civil Society” explains that because civil society stands outside of the “dominant logics” of the economy and the nation-state, democratic action by civil society can play a critical role in guiding of our economic and administrative systems towards sustainability. However, he asserts, this cannot happen unless we foster a broad-based democratization of the political arena, openly acknowledge the current dire status of the environment, and develop an alternative vision of an ecologically sustainable society to serve as an inspiration to social movements capable of effecting social change. What is missing from this compilation of chapters? It would have been good to include a pointed discussion of how power dynamics play out in all the issues addressed in these chapters, an analysis of realistic alternative economic systems and goals other than the profit-oriented neoliberal model, and an assessment of how

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we human societies got ourselves into the current mess. Furthermore, it would be wonderful to find a way to bring in the voices of ordinary people from around the world: poor, rich, or middle class; well informed or devotees of the worst of popular media – we need to know what people of diverse cultures and socioeconomic circumstances are thinking. A global survey of social scientists and other researchers involved in global environmental change studies was conducted in 2011 by the International Human Dimensions Programme on Global Change. The primary finding was that most respondents feel that the social dimensions of the topic are very important but under-addressed. The highest-priority research areas identified by respondents included: 1. equity/equality and wealth/resource distribution 2. policy, political systems/governance, and political economy 3. economic systems, economic costs, and incentives 4. globalization and social and cultural transitions. Over 80 % of these scientists would like to see additional funding and opportunities for such research, and 90 % support an assessment of social sciences and humanities research findings applicable to global environmental change. It is our intention that this compilation of chapters will represent one small piece of the essential move towards bringing the social sciences to the table as full partners in the search for understanding and solutions regarding global environmental change.

References Duraiappah AK, Rogers DS (2011) Survey of social sciences scholars on engagement in global environmental change research. International Human Dimensions Programme on Global Environmental Change (IHDP), Bonn Rogers DS, Bala´zs B (2013) Poverty, inequality, and the distribution of wealth. In: Pogge T, Ko¨hler G, Cimadamore AD (eds) Poverty & the Millennium Development Goals (MDGs): a critical assessment and a look forward. Zed Books, London (forthcoming)

Defining and Measuring Human Well-Being

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David A. Clark

Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Measuring Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Income and Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “List-Orientated” Views: Basic Needs, Human Rights, and Capabilities . . . . . . . . . . . . . . . . . . . . . Measuring Human Well-Being in Multiple Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sustainable Well-Being and the Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

Human well-being is a complex concept that has been contested across the social and political sciences. This chapter considers three broad approaches to the concept and measurement of human well-being along with their respective merits from a cross-disciplinary perspective. The three broad approaches in question embrace utility (happiness, desire fulfillment, and preference), material well-being (most notably, income and resources), and “list-orientated” views (needs, rights, and capabilities). The final part of the chapter explicitly links human well-being with environmental issues and various notions of sustainable development. It is suggested that the idea of “sustainable human development” can help resolve the apparent tension between poverty reduction (involving more consumption) on the one hand and environmental conservation and sustainability on the other. Above all, a more comprehensive account of human well-being is required to bridge the gap between mental and physical states and to take note of the environmental and material basis of sustainable well-being.

D.A. Clark Centre of Development Studies, University of Cambridge, Cambridge, UK e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_66, # Springer Science+Business Media Dordrecht 2014

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Keywords

Well-being • Utility • Income • Basic needs • Human rights • Capability approach • Social indicators • Environment • Sustainable development

Introduction Human well-being is a complex concept that embraces many different ideas and perspectives. Many notions of well-being can be found in philosophy, psychology, and economics as well as social and political science generally. The fact that many discussions of well-being take place within the narrow confines of specific intellectual disciplines serves only to increase the fog surrounding the concept. For this reason, cross-disciplinary efforts to shed new light on the concept and meaning of human well-being are particularly welcome – especially when these efforts combine theory and practice with rigor and care. Some notable attempts to combine different streams of work on well-being can be found in the human development and environmental literatures. Human well-being is difficult to define and even harder to measure. In fact, “define” is perhaps the wrong word to use, given the many different overlapping and competing ways in which the concept has been specified and employed. In everyday usage, well-being is associated with mental and physical health including aspects of “healthy living” such as diet, exercise, and inner harmony.1 In philosophy and social science, well-being is usually defined more broadly to include happiness, the satisfaction of desires, and “living and fairing well” or flourishing (i.e., the realization of a “good” form of life). According to the Oxford English Dictionary (1989), well-being is “the state of doing or being well in life” which covers a “happy, healthy, or prosperous condition” and the “moral or physical welfare” of a person or group.2 For all their variety, most concepts of well-being in philosophy and the social sciences share some common characteristics, although some of these have been queried. For example, well-being is often applied purely to a person’s self-interest (what is “good” for them) rather than “other regarding” goals and commitments (what is “good” for others). Yet it is not hard to find examples of trade-offs in personal well-being among family and friends (e.g., Dolan et al. 2008, pp. 111–122)

1

The World Health Organization defines health in terms of well-being: “Health is a state of complete physical, mental and social wellbeing and not merely the absence of disease or infirmity” (WHO 1948, p. 1). Of course, it is possible to challenge such concepts. Many people choose lifestyles with unhealthy elements (drinking alcohol, smoking cigarettes); and on occasions even apparently “healthy” activities can be harmful (over dieting, excessive exercise) (see Clark 2002, 2005). 2 Secondary definitions refer to the “satisfactory condition (of a thing)” and “individual instances of welfare.” The focus here is entirely on human well-being. I also set aside the discussion of wellbeing and morality (except insofar as moral conduct is thought to contribute to living and faring well). See Griffin (1986), Crisp and Hooker (2000), and Crisp (2008) on morality and well-being.

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or of altruistic acts (e.g., involving concern for the environment) that benefit the society at large (e.g., Sen 1977; Meeks 1991). Some notable attempts have therefore been made to develop concepts and measures of agency that capture valuable goals and achievements beyond personal well-being (e.g., Sen 1985a; Crocker 2008; Alkire 2008). In addition, most concepts of human well-being are multidimensional and incorporate positive and negative aspects of life. Multidimensionality recognizes that many different achievements and activities spanning diverse spheres of life contribute to human well-being. It is possible to perform well in some of these dimensions (good health, high level of education, satisfactory job) without performing so well in others (poor personal relationships, breathing polluted air). The flipside of well-being is sometimes referred to as “ill-being” or disadvantage. Some commentators recognize the importance of at least some antagonistic elements of life for human well-being (Scivotsky 1976, p. 62; Braybrooke 1987; Clark 2005). For example, Martha Nussbaum (1995, p. 80) states, “It is a characteristic of human life to prefer recurrent hunger plus eating to a life with neither hunger nor eating; to prefer sexual desires and its satisfaction to a life with neither desire nor satisfaction....” It is worth remembering that the mainstream tendency to reduce well-being to income or happiness is not necessarily at odds with these insights; broader concepts of well-being and freedom can usually be found behind these narrow metrics (see Clark 2002, pp. 19–21).3 It is usual to distinguish between subjective and objective forms of well-being in the literature. Subjective well-being is usually concerned with how a person thinks or feels about their life (Kahneman et al. 1999, p. ix; Diener et al. 1999, p. 277; Dolan et al. 2008, p. 95), whereas objective well-being focuses on external tangible conditions (Diener 1984, p. 12; Griffin 1986, p. 32; Cummins 2000), such as the person’s “physical state” or the quality of their surrounding environment (e.g., Sen 1985b).4 These distinctions, however, are misleading insofar as most accounts of human well-being include both objective and subjective elements. For brevity, this chapter briefly considers three main approaches to human well-being: utility (happiness, desires, and preference), income and resources, and “list-orientated” views (needs, rights, capabilities) which typically include some mental states (in this chapter I set aside the discussion of primary goods (e.g., Rawls 1971) and prudential values (Griffin 1986; Qizilbash 1998) due to space constraints).

3 Jeremy Bentham’s (1789) account of happiness as the sole basis of goodness devotes an entire chapter to cataloging 14 distinct types of pleasure and 12 kinds of pain. Some of the sources of these pleasures and pains are reminiscent of various capabilities, needs, and rights. There is a strong case for installing “time” in terms of the duration of relevant experiences (Clark and Hulme 2010) and “sustainability” (discussed presently) as additional features of wellbeing. 4 In contrast to the former, the latter usually takes the form of an independent assessment of human flourishing or need. An analogous distinction relates to “hedonic” and “eudaimonic” well-being (see Ryan and Deci 2001).

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Utility Subjective concepts and measures of well-being view goodness in terms of utility, i.e., happiness or the satisfaction of desires. The roots of classical utilitarianism (the happiness view) are normally traced back to Jeremy Bentham’s (1789) Introduction to the Principles of Morals and Legislation, although the same idea can be found in ancient Greek philosophy. Bentham observes that “Nature has placed mankind under the governance of two sovereign masters, pain and pleasure. It is for them alone to point out what we ought to do. . .” (p. 1). Consequently, well-being consists of the greatest happiness, measured according to the duration and intensity of pleasure and pain (▶ Chap. 4). Classical utilitarianism has enjoyed a revival in recent years partly due to Richard Layard’s (2006) influential book, Happiness: Lessons from a New Science (see also Oswald (1997) and Frey and Stutzer (2002), among others). Layard reaffirms the view that the best society is the happiest society (pp. 112–113) and reiterates the old argument that what makes people happy is generally good for them (pp. 23ff). According to Layard, the greatest happiness principle is “fundamentally humane, because it says that what matters ultimately is what people feel” (p. 5). Less convincingly, he goes on to argue that “unlike all other goods, happiness is ‘self evidently good’” (p. 113, my emphasis). It can therefore be used as an overarching principle of arbitration to value other goods, to assess rules or institutions, and to judge the goodness of actions (pp. 113, 124–125). One worry is that maximizing the total sum of utility will generate inequalities and undermine the well-being of the vulnerable. Specifically, Amartya Sen (1980) has argued that Benthamite utilitarianism discriminates against people who are relatively less efficient in converting income into happiness. This is because a strict utilitarian would award more income to a “pleasure wizard” than a grump with a marginal utility disadvantage at the relevant point. This could raise serious problems for many people with disabilities or extraordinary needs who require more income and resources (wheelchairs, ramps, expensive drugs) to achieve the same basic human functions (moving around, mental and physical health). Such people are “doubly worse off” according to Sen: they not only get less utility or pleasure from a given income but also end up with less income (p. 203).5 This criticism, however, as Sen recognizes, applies to the goal of maximizing the total utility of a society, rather than to the relevance of the “happiness” principle itself. In short, it does not comprehensively defeat the happiness view of wellbeing. Moreover, it might be argued that this criticism is too harsh. Although classical utilitarianism in its simplest form is often associated with maximizing

5

Gay Meeks has reminded me that Sen later recognizes this criticism will not apply if the person in question has an “undentable” cheery disposition. The argument that the disabled will become “doubly worse off” also depends on the implicit assumption that other people’s utility functions will not be adversely affected.

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the total sum of utility, Bentham himself spoke of “the greatest happiness of the greatest number” (this quote is from Bentham’s (1776) first published work and does not reappear in Morals and Legislation). Similarly, in his reinterpretation of the happiness view, Layard argues that the greatest happiness principle is “inherently pro-poor” as the poor hate poverty and have the most to gain in happiness terms from a rise in income (pp. 8, 33, 120–121). Another criticism involves recognizing that different forms of pleasure and pain ought to be weighed differently. This is reminiscent of Thomas Carlyle’s “philosophy of the swine” objection, which holds that basic utilitarianism places all pleasures on an equal footing, irrespective of whether they happen to be the lowest animalistic pleasures of sex or the highest intellectual or aesthetic forms of enjoyment (see Crisp 2008, p. 7; Dorsey 2013). Such concerns date back to Aristotle, who grumbled that the “most vulgar” in society, who seek only pleasure, choose a life comparable to that of “grazing animals” (Nicomachean Ethics, 1095b17–1096a4). A related criticism recognizes that utility does not address what Cohen (1993, p. 12) calls “offensive tastes”: the pleasure or satisfaction derived from discriminating against other people or violating their liberties (see also Rawls 1971; Sen and Williams 1982). Nor does the happiness view recognize that some choice-worthy activities (such as risking one’s life to save a drowning person) may not be remotely pleasurable (see Sen 1985a; Nussbaum 2011, p. 126). One way of dealing with these problems is to make some adjustments to the relative weights of pleasure and pain.6 Another landmark in the literature is John Stuart Mill’s (1861) Utilitarianism, which helps to address pig philosophy and offensive tastes. Instead of viewing happiness as a simple homogenous state, Mill distinguishes between “higher” and “lower” pleasures, which suggests that utility should be judged – and ultimately measured and weighed – in terms of quality as well as duration and intensity. Among the higher pleasures are qualities such as nobility and the gratification associated with intellectual pursuits and the cultivation of the mind (pp. 139ff). Mill is adamant that “It is quite compatible with the principle of utility to recognize the fact that some kinds of pleasure are more desirable and more valuable than others” (p. 138). Yet it is often suggested that by introducing “quality,” Mill’s version of utilitarianism represents a step away from formal hedonism, under which pleasure is gauged in terms of duration and intensity alone (Crisp 2008, p. 7). Moreover, by arguing that some pleasures are more valuable and more worthwhile

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At the extreme we might regard some types of utility (e.g., the pleasure or satisfaction derived from subjecting another person to a lesser liberty) as “wrong” and argue the case for striking these pleasures or desires from utility functions (e.g., Rawls 1971, p. 31). Jim Griffin argues that similar criticisms apply to the desire fulfillment view of utility which is considered presently. He considers the case for excluding “immoral desires” such as those based on sadistic wishes (Griffin 1986, Chap. 2).

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than others, Mill’s approach runs the risk of becoming grossly paternalistic (as Layard 2006, p. 23 argues).7 There are, of course, other objections to the happiness view that are even harder to defend against. For example, it is often said that there is more to well-being than achieving happiness or avoiding pain. Other things matter too, such as health, basic liberties, close personal relationships, self-respect, and physical security. Although the happiness principle may be able to help us value and even choose between some goals and objectives, it is difficult to see how the view that nothing else has independent value (e.g., Layard 2006, pp. 112–113) can be sustained. At the heart of this view is the belief that “health, autonomy and freedom are ‘instrumental goods’. . . [because] we can give further more ultimate reasons for valuing them” (p. 113). However, the fact that we value the happiness derived from these goods does not exclude the possibility that we may value health, autonomy, or freedom in itself. The available evidence, although not easy to interpret, tends to support this intuition. In response to open questions about “what constitutes a good form of life?” and “why?” people typically mention a range of important ends and cite different reasons for valuing them (including, but not limited to, the pursuit of happiness) (see Clark 2002, 2005). The realization that well-being is inherently multidimensional has prompted one Nobel Prize-winning economist and philosopher to argue that the relevance of nonutility information “is the central issue involved in disputing Welfarism” (Sen 1982, p. 363). Another approach involves reinterpreting utility more broadly to capture the fulfillment of actual desires. Instead of viewing utility as “happiness” or “pleasure,” it is now effectively represented by a person’s preferences (Broome 1991, p. 3). A focus on actual desires has certain advantages. It recognizes that well-being is not a homogenous state (even if it does not adequately get to grips with multidimensionality8), respects personal autonomy and choice (the individual’s preferences are paramount), and leaves no room for paternalism (in defining “good” and “bad” activities or forms of life). It also allows economists to observe actual desires insofar as preferences are revealed through choice.9 Actual desires, however, may extend beyond personal well-being to include the quality of other people’s lives. This raises the tricky issue of how far, if at all, “other regarding” desires should 7

Consider Mill’s (1861) classic conclusion: “It is better to be a human being dissatisfied than a pig satisfied; better to be a Socrates dissatisfied than a fool satisfied. And if the fool, or pig, is of a different opinion, it is because they only know their own side of the question” (p. 140). Sugden (2006, pp. 43–4) reminds us that Mill’s utilitarianism should not be confused with his liberalism: Mill holds that social evils such as drunkenness and gambling should be permitted (as long as no harm comes to others), even though these activities are harmful to the agent’s own happiness and well-being. 8 The adaptation argument is considered shortly. 9 The “revealed preference” approach has helped to make economics a respectful empirical science, although it has been criticized by some economists (e.g., Hahn and Hollis 1979, Chap. 1; Meeks 1991). In particular, Sen (2002, esp. Chap. 3) has expressed concerns about the “internal consistency of choice” by maintaining that some choices violate basic axioms of rationality such as transitivity.

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count – assuming, of course, that it is even possible to separate self-regarding and other-regarding desires (Griffin 1986, pp. 24–25; Qizilbash 1998, p. 58–59).10 A more common objection is that actual desires may be “faulty” or mistaken in some way: people may be ill-informed (lack relevant information) or might make logical mistakes (Griffin 1986, pp. 12–13; Qizilbash 1998). Some desires may also be prone to addiction (Parfit 1984, p. 497) which erodes willpower. In short, preferences may need correcting and choices may not reflect true interests. These difficulties have pushed some advocates of utilitarianism in the direction of an informed desire account of well-being. In this approach, desires count toward utility only insofar as they are “rational” and “informed.” Of course, the extent to which a person can be fully rational and informed is debatable. Human beings not only lack access to relevant information, they are also subject to cognitive limitations which make it difficult to process and make sense of large amounts of information (Simon 1982; see Qizilbash 1998, pp. 59–60). Moreover, even properly informed desires can be queried. In a well-known example, John Rawls (1971) considers the fanciful case of a fully informed and gifted mathematician whose sole enjoyment in life is counting blades of grass. Rawls contends that if we accept that this activity really is in the mathematician’s nature, then it must follow that any rational life plan for this person must revolve around counting blades of grass – a conclusion that is counterintuitive and conflicts with other principles of well-being (pp. 379–380). Nor is it clear that irrational desires should be completely discounted. Jim Griffin (1986, p. 25) cites the case of a “compulsive hand washer,” whose desire is groundless, although its fulfillment still generates utility. Other difficulties discussed at length by Griffin (1986) include the fact that people may have to go through “daunting improvements” to appreciate certain desires. Developing a taste for caviar, fine literature, classical music, opera, or polo may all fall into this category. Following on from this is the question of how to strike a balance between actual and informed desires. To what extent should tastes be developed? Refining tastes also implies “blurring” the distinction between values and desires. Do desires even matter anymore, if they must be informed, weighed, and appreciated? Griffin also argues that the desire approach cannot provide a “global” or “unitary” account of a person’s well-being. Totting up desires may facilitate short-term comparisons and trade-offs but is far less helpful when it comes to saying that one way of living, on the whole, is better or worse than another. A person may prefer a life with lower total utility and fewer awful years to one with a higher utility score punctuated by dramatic peaks and troughs (“good” and “bad” events). The relative contribution of fulfilling any particular desire also depends on the blend of desires actually achieved. A diverse or well-rounded form of life may be more valuable than an incomplete life that lacks some fundamental end (such as autonomy, health,

10

In particular, there may be a case for excluding immoral or sadistic desires such as “hate, envy, spite, prejudice and intolerance” (see Griffin 1986, pp. 24, 25–26) – especially if these desires are permitted to affect other people’s well-being.

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or love) even if the latter scores highly in other spheres. In sum, the distribution and composition of utilities matter. Two further arguments relating to adaptation and social comparisons, on the one hand, and the “experience machine,” on the other, are often invoked to criticize variants of utility as concepts and measures of human well-being. The adaptation argument features prominently in the work of Jon Elster (1983), Amartya Sen (1985b), and many others. The basic proposition is that a person’s happiness, desires, and choices adjust to reflect circumstances and possibilities. Specifically, Sen (1992, p. 55) is concerned that the poor and disadvantaged may learn to “take pleasure in small mercies and to cut down personal desires to modest – realistic – proportions” to avoid bitter disappointment and to cope with the harsh realities of life. A person’s preferences may also be corrupted by social conditioning or blatant forms of inequality, exploitation, and injustice (see also Nussbaum 2000). Adaptation can take many different forms and typically varies across time and place (see Clark 2012). Social psychologists and economists tend to emphasize hedonic adaptation.11 Hedonic adaptation tries to explain why an increase in income only leads to a temporary rise in happiness or satisfaction. Over time, the initial effect on utility is countered by rising income aspirations and frustrated expectations. The result is the “hedonic treadmill” which obliges people to repeatedly strive for higher incomes in a mistaken and futile attempt to increase long-term happiness.12 Two mechanisms typically drive higher income aspirations: social comparisons with significant others (“keeping up with the Joneses”) and prior experience (fuelling expectations that income will rise again). The important point to note is that adaptation – in its various guises and forms – can turn utility metrics into unreliable guides to personal well-being. Robert Nozick’s (1974) experience machine represents another challenge. Imagine a machine that can simulate any desire and leave the subject with the impression that they are actually living an extremely happy and satisfying life. For argument sake, assume that the subject has no obligations to other people and can choose to either leave or reprogram the machine at regular 2-year intervals. Should the person in question plug in? Does the case for plugging into the machine change if the person is faced with a stark choice between virtual bliss and real hardship? In making a decision, we have to consider what else matters apart from experience. Nozick suggests that, in fact, we also want to “do” and “be” certain things. We do not just want the experience of doing something or the illusion of having done it. We also want to be someone, a certain kind of person, with our own 11 See, for example, Brickman and Campbell (1971); Diener, Lucas, and Scollon (2006); and Layard (2006, Chap. 4). The hedonic treadmill is consistent with the “Easterlin Paradox” – the finding that rapid growth in the advanced economies since the 1950s is associated with stable or declining happiness scores (Easterlin 1974). 12 In theory, the hedonic treadmill also works in reverse (a decline in income produces lower aspirations), although there is some evidence to suggest that adaptation is asymmetric: people adapt more to a rise in income but less so to a decline in income (see Clark 2012).

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character and identity, rather than an “indeterminate blob” lying dormant inside a machine.13 One reason why the experience machine seems persuasive is that Nozick may only need to show that not everyone would plug in, not that no one would, for his underlying argument to have some force.

Measuring Utility There have been many attempts to measure utility in economics and psychology. Following on from Bentham, initial attempts to measure happiness focused on what has become known as experienced utility – continuous hedonic flows of pleasure and pain.14 An example is Edgeworth’s (1881) farsighted proposal for a “hedonimeter” that would be able to directly monitor experiences “according to the verdict of consciousness” (p. 101).15 Actual attempts to measure instant utility focus on integrating momentary episodes of pleasure and pain experienced in real time. This normally involves gauging mental reactions in a laboratory setting by asking the subject to rate the quality of their experiences on a set scale (with a neutral middle point) by pulling a lever, turning a dial, or pressing a button. Another type of experienced utility is remembered utility – the way in which the subject recalls mental reactions once the experience is over. Retrospective assessments of past episodes of utility are more practical for policy purposes than real-time measures, which are generally confined to controlled environments over short-lived periods of time. Several studies have compared instant utility with remembered utility by asking the subject to rate their overall experience following the initial experiment. These studies suggest that while people remain fairly good at classifying past experiences as pleasurable or painful, their retrospective assessments are subject to various forms of “systemic bias” (the neglect of the duration aspect of experience, the overemphasis of relatively intense experiences) that hamper measurement (see Kahneman and Krueger 2006). In contrast, decision utility relates to revealed preference and the choices people make rather than their subjective experiences. In economics, decision utility is inferred from market behavior or stated preference studies in order to estimate the utility associated with different choices and outcomes. The main limitations of this

13

Nozick is also concerned that an experience machine would limit the world to a manmade construct that prevents the exploration of deeper realities (although the experience can be simulated). 14 The distinctions between experienced utility (including instant and remembered forms) and decision utility employed in this section have origins in the writings of Daniel Kahneman (e.g., Kahneman et al. 1997) and also feature in several of the chapters collected in Kahneman, Diener, and Schwartz (1999). Kahneman’s use of these terms has evolved over the years. 15 Layard (2006, pp.17–20) and Colander (2007) describe some of the breakthroughs in neuroscience and brain wave analysis that make the hedonimeter more of a practical possibility than a farfetched proposal.

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approach have already been mentioned: inconsistent preferences, evolving preferences, “other” regarding preferences, and various forms of adaptation including interdependent preferences. A further criticism recognizes that merely observing human behavior and choice is unlikely to tell us much about the constituent components of well-being in contexts where actual opportunities are limited (Clark 2002, pp. 103–104). Given the drawbacks of decision utility as a measure of well-being and the limited potential for utilizing instant measures of utility, the remainder of the discussion will focus on other measures of utility featured in the subjective well-being (SWB) literature.16 Global measures of SWB (not to be confused with international measures) typically ask about perceptions of life as a whole.17 A common example of a “happiness” and “life satisfaction” question taken from the sixth wave of the World Values Survey (2010–2012)18 reads as follows: • Taking all things together, would you say you are (read out and code one answer): 1 Very happy 2 Rather happy 3 Not very happy 4 Not at all happy • All things considered, how satisfied are you with your life as a whole these days? Using this card on which 1 means you are “completely dissatisfied” and 10 means you are “completely satisfied” where would you put your satisfaction with your life as a whole? Many of these surveys exclude a neutral middle point (as in the above examples) or avoid reading out a “neither/nor” option, to encourage respondents to distinguish between positive and negative experiences.19 Single-item measures of SWB are often criticized as less reliable than multi-item measures which are based on responses to more than one question. This is because single-item measures cannot be tested for internal consistency, tend to produce skewed results (with most responses falling into positive categories), and rely on the subject being able to provide a single integrated response covering many dimensions of well-being.20

16

In addition to remembered utility (retrospective happiness), other measures might include perceptions of current or future happiness as well as “life satisfaction” which Kahneman believes captures something more than experienced utility (see Jarden 2011). 17 The following discussion sets aside domain-specific questions that focus on subjective impressions of particular aspects of life (health, relationships, housing, work, finances, children, etc). 18 See WVS (2011) and questions V10 and V21. For a catalog of single-item happiness and life satisfaction questions derived from leading surveys, see Dolan, Peasgood, and White (2008, appendix A). 19 The British Household Survey and Russian Longitudinal Monitoring Survey both have scales with neutral middle points. 20 Studies show that single-item measures possess “moderate reliability” over time and correlate with external factors and other subjective well-being measures. For further discussions, see Diener (1984) and Krueger and Schkade (2008).

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More generally, responses to SWB questions can be influenced by momentary mood, personal traits, cultural factors, and different understandings of “happiness” and “satisfaction.” Responses can also be affected by preceding survey questions, interviewer bias, and conscious distortion (see Diener (1984, pp. 14–17, 22–24) for further discussion of these issues; see also Bertrand and Mullainathan (2001) and Clark (2002)). For these reasons, a lot of effort has been devoted to improving existing methods, measures, and checks. Some economists now argue that it may be better to compare SWB measures than to rely on revealed preference if people are subject to the kinds of “bounded rationality” discussed above and their decisions and choices fail to closely reflect their own happiness (e.g., Kahneman and Krueger 2006, p. 3).21

Income and Resources Income and resource-based approaches are sometimes put forward as concepts and measures of human well-being. In economics the focus is normally on household income and consumption at the microlevel and GNP – or GNP per capita – at the macro and global levels. The limitations of GNP as a concept and measure of human well-being are well known (see Hicks and Streeten 1979; Sarkosy Report 2009). The apparent drawbacks are not surprising given that the statistic was designed to measure total economic production (see Hartwick 2006) rather than “economic welfare” or human well-being.22 In particular, GNP is not concerned with the distribution of income, overlooks nonmarketed activity (such as domestic work), fails to pick up some informal sector activity (which is vast in developing countries), and makes no allowances for leisure time, defense spending, or environmental degradation (all of which affect the quality of life).23 None of these criticisms, however, logically imply that the material basis of well-being should be shunned. Income and growth may ultimately be necessary, if not sufficient by themselves, for sustained human well-being and development (Sen 1999; Clark 2002, 2006).

21

Many attempts have been made to measure subjective well-being at the national, regional, and global levels. Noteworthy examples include the UK’s so-called “happiness” index (Self et al. 2012), the Cambridge Well-Being Institute’s study of happiness levels across Europe (Huppert and So 2013), and the analysis of satisfaction data from the Gallup World Survey (Deaton 2008). In 2012 the first World Happiness Report was launched at the United Nations (Halliwell et al. 2012). 22 A fact long recognized by economists and their critics alike. See, for example, Hicks and Streeten (1979), Oswald (1997), and Daly (2006, p. 657). 23 Various adjustments to GNP have been proposed. A noteworthy example is William Nordhaus and James Tobin’s “Measure of Economic Welfare” discussed by Hicks and Streeten (1979) and Daly (2006).

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“List-Orientated” Views: Basic Needs, Human Rights, and Capabilities In the 1970s, increasing concern about the persistence of (monetary) poverty, inequality, and unemployment led some to call for the “dethronement of GNP” (Seers 1972) and “redistribution with growth” (Chenery et al. 1974) along with greater reliance on social welfare indicators. This gave rise to the basic needs approach – the forerunner of today’s human development paradigm. The original basic needs approach (BNA I) focused on access to minimal levels of basic goods and services, such as food, clothing, and shelter or access to water and sanitation (ILO 1976, p. 7). The emphasis on the material aspects of well-being was quickly broadened to cover “providing all human beings with the opportunity for a full [or ‘minimally decent’] life” (BNA II) which involves meeting basic needs (Streeten et al. 1981, p. 21; Stewart 1996, p. 46, 2006).24 The shift in emphasis toward opportunity and choice makes it is harder to charge later versions of the BNA with paternalism or commodity fetishism.25 Another prominent approach to well-being champions the notion of human rights. At the heart of this approach is “the fundamental belief that the protection of human dignity and equality is a responsibility of society at all its different layers and levels” (de Gaay-Fortman 2006, p. 261). Human rights have a long history, although their endorsement and implementation at the global level received a major boost with the founding of the United Nations in 1945, the Universal Declaration of Human Rights in 1948, and subsequent international covenants and summits. Given that human rights are internationally recognized and firmly entrenched as requirements for human dignity, they are typically regarded as “indispensable,” “indivisible,” and “inalienable” aspects of human well-being. They are sometimes divided into first generation rights which embrace civil and political liberties and second generation rights which appeal to economic, social, and cultural entitlements. Second generation rights generally receive less attention and more criticism as “universal components” of human rights. Human rights are sometimes criticized for having “dubious foundations” or unclear origins. Jeremy Bentham (1843) famously dismissed rights altogether as nonexistent rhetorical “nonsense upon stilts” (p. 53). One difficulty is that the approach does not adequately define corresponding duties to protect rights (a controversial area in itself), although the notion of “imperfect obligations” arguably helps (see Vizard 2010). Another worry is that a too-exclusive rightsbased approach might allow rights to “trump” everything else, so that a relatively small-scale right holds sway even if it involves disastrous consequences on another front (Dworkin 1984). Rights-based approaches are also difficult to implement 24

A minimally decent form of life is typically defined in terms of health, nutrition, and literacy levels (Stewart 1996, p. 46). While BNA II endorses broader goals, practical applications tend to focus on material goods and services (Stewart 2006, p. 16). 25 Elsewhere I have argued that some other accounts of need (especially “human need,” “genuine needs,” and “authentic needs”) are susceptible to paternalism (Clark 2002, 2012, Chap. 3).

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(given the inherent limitations of legal and political systems and the fact that global poverty undermines economic entitlements) and can be “easily twisted” in order to exclude certain people or groups (see de Gaay-Fortman (2006) and Sen (2004) for an overview and assessment of these criticisms). Some scholars have therefore called for the development of an explicit theory of human rights to address these concerns (e.g., Sen 2004). The conceptual foundations for an objective approach to well-being are provided by Amartya Sen’s (1985b, 1999, 2009) capability approach (CA). The CA has become increasingly influential in recent years and is firmly entrenched in critiques of welfare economics (utility, income, resources), although its roots can be traced back to Aristotle, Adam Smith, and Karl Marx (among others). It maintains that there is more to life than achieving happiness or realizing desires. While it is important to take note of utility, there are many other things of intrinsic value. It also embraces Aristotle’s argument that “wealth is evidently not the good we are seeking; for it is merely useful and for the sake of something else.”26 Moreover, neither utility nor income/resources may be reliable proxies for well-being. Happiness and desires may adapt to reflect straitened circumstances (as we have seen), while income and wealth tell us nothing about the differential capacities of human beings to transform resources into key achievements. It is therefore necessary to focus directly on the freedom to achieve human capabilities, such as being able to live long, be well nourished, achieve literacy, take part in the life of the community, and achieve self-respect (Clark (2002, Table 3.1) provides a catalog of many of Sen’s examples of capabilities). Although Sen provides many isolated examples of capabilities, he refuses to endorse a fixed or definitive list as “objectively correct” (see Clark (2006) for an overview of the debates covered in this paragraph and appropriate references to this literature). Instead he seeks to promote agency and encourage participation by arguing that any substantive list of capabilities should emerge through the process of public reasoning and valuation – the precise form of which is not clarified (Sen 2009, pp. 241–243). Some critics, including Martha Nussbaum, have argued that Sen needs to be bolder. Surely any account of substance should endorse a coherent list of the constituent elements of a good life? In response, Sen argues that the flexibility and pluralism of the CA are important virtues; he also points out that the CA has considerable “cutting power” as it stands (given that it broadens the informational base for evaluating well-being). While the open-endedness and inclusiveness of the CA has much to recommend it, these very considerations have led some to question the possibility of making the approach operational, given the potential for disagreement among reasonable people regarding the selection and weighting of capabilities (Sugden 1993). This criticism, however, tends to conflict with the available evidence on value formation (e.g., Clark 2002; Clark and 26

The quotation here is from David Ross’s translation of Nicomachean Ethics, book I (Oxford World Classics), 1095b5–7, which is slightly different from the translation provided by Irwin cited in the bibliography. I have stuck with the Ross translation, as it is frequently referred to in the wellbeing literature by Sen and others.

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Qizilbash 2008) and predates many notable attempts to apply the CA (e.g., Comim et al. 2008; Chiappero-Martinetti 2009; Biggeri et al. 2011). A well-known attempt to develop an alternative approach that endorses a list is Martha Nussbaum’s (2000, 2011) “capabilities approach.” Nussbaum draws on Aristotle and the ancient Greek tradition to develop a list of ten “central capabilities” that form the basis of “fundamental entitlements” that the state is obliged to support and protect in accordance with “human dignity.” The capabilities on her list include (1) life; (2) bodily health; (3) bodily integrity; (4) senses, imagination, and thought; (5) emotions; (6) practical reason; (7) affiliation; (8) other species; (9) play; and (10) control over one’s environment – political and material. In theory, these capabilities are plural, qualitatively distinct, preserve an element of freedom (for responsible adults, at least), and are subject to scrutiny and revision. In practice, the way Nussbaum develops and refines her list of capabilities has been heavily criticized (Clark 2002, 2013; Okin 2003; Jaggar 2006). Like many other “lists” of the constituent components of well-being, it has been described as authoritarian, elitist, and objectionably paternalistic. Some studies have also shown that the lists of capabilities or needs emanating from philosophy and social theory sometimes conflict with the values and aspirations of ordinary people. Many of these lists also need to say more about the practical side of minimal and decent forms living, the importance of psychological achievements (confidence, peace of mind), and the role of leisure in promoting well-being (Clark 2003). Some accounts of well-being also need to tone down sharp contrasts between virtue (intellectual pursuits, opera, mineral water) and vice (television, pop music, and Coca-Cola) (Clark 2005).

Measuring Human Well-Being in Multiple Dimensions Over the years there have been many attempts to measure multidimensional aspects of human well-being. Many of these measures are based on composite indicators of well-being that seek to combine distinct elements, although other approaches allow for imprecision (in defining well-being) or favor a system of social accounting that permits the disaggregation of principal components and indicators. An early attempt to construct a composite measure of well-being emerged in the form of Morris and Liser’s (1977) Physical Quality of Life Index (PQLI). The index itself is essentially an average of three “basic need” indicators – life expectancy, infant mortality, and literacy. Although ahead of its time, a range of concerns were raised (see Hicks and Streeten 1979), many of which have resurfaced with reference to more recent composite measures. The PQLI has been largely eclipsed by the Human Development Index (HDI) which has been published annually for most countries since 1990 in the Human Development Report. The original HDI focused on three core dimensions of human well-being: living standards (GDP per capita), health (life expectancy), and education (literacy in 1990; literacy combined with mean years of schooling, 1991–1994; and literacy combined with gross enrolment from 1995). While the original index evolved from 1990, the most fundamental changes came with the introduction of

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what has become known as the “new” HDI in 2010 (see Klugman et al. 2011; UNDP 2010). These changes consisted of (1) the selection of new indicators for two dimensions (GNI per capita to represent living standards and opportunities; and mean years of schooling and expected years of schooling as proxies for education), (2) a switch from arithmetic to geometric means for calculating indices, and (3) refining the upper and lower boundaries used to normalize the index.27 Over the years the HDI has received a lot of attention and scrutiny. In particular, concerns have been raised about the selection and weighting of indicators, the computational methodology, the robustness of rankings, and the potential redundancy of the index (see Ravallion 2011; Klugman et al. 2011). Two problems with the HDI are worth flagging. First, persistent changes in the computation of the HDI and associated indicators means that even before 2010, the indexes published in annual reports are not strictly comparable. (Fortunately the 2010 and 2011 reports both provide a standardized HDI for selected years) (some rudimentary tools for exploring the HDI over time are available on the HDRO website, http://hdr.undp. org/en/data/explorer/). Second, overreliance on three core dimensions (not to mention the practice of averaging across these dimensions) suggests that the HDI may conceal at least as much as it reveals about the nature of human well-being and development. To quote Amartya Sen (2006), the HDI “is a quick and imperfect glance at human lives, which – despite the crudeness it shares with the GNP – is sensitive, to a significant extent, to the way people live and can choose to live . . . However, the breadth of the human development approach must not be confused with the slender specificity of the Human Development Index” (p. 257). One response is to develop a system of measurement capable of embracing the complexity and ambiguity of human well-being. Fuzzy set theoretic measures start to do this by allowing for approximate thresholds of income that fall within given boundaries. Mozaffar Qizilbash takes fuzzy logic a step further by allowing for vagueness among the dimensions of poverty and well-being as well as for approximate threshold levels (see Clark and Qizilbash 2008). The result is a framework that can distinguish those who are definitely poor, those who are definitely not poor, and those who are “neither/nor” (given the many plausible specifications of poverty and well-being). While this framework is closely related to the human development and capability approach, it does require a lot of data and may yield results that are not easy to compare if the selection of admissible dimensions and thresholds varies across people and cultures or over time (Clark and Hulme (2010) extend the framework to include time and duration). Another response involves developing a system of accounting for managing a diverse set of social indicators. This approach allows us to monitor many different 27

Several companion measures such as the Human Poverty Index, Gender-Related Index, and inequality-adjusted HDI have been developed (http://hdr.undp.org/en/statistics/indices/). Early attempts to develop a Political Freedom Index and Human Freedom Index were discontinued on the grounds that they were based on “qualitative judgments, not quantifiable empirical data” (UNDP 2000, p. 91).

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aspects of well-being simultaneously and rapidly spot any disparities in key indicators. Although social accounting systems offer no headline statistic to capture imagination and may be difficult to comprehend in cases where there are lots of overlapping or conflicting statistics, the initial concern regarding the availability of suitable data and relevant indicators is far less valid today than it was in the 1970s. Some contributions have explored criteria for selecting indicators with desirable properties (e.g., Atkinson et al. 2002; Clark 2008). Others have tried to develop a set of “capability indicators” intended to cover various aspects of well-being that can be derived from widely available survey data (Anand et al. 2009). The most well-known set of indicators and targets are embedded in the Millennium Development Goals (MDGs), which have been described as “the world’s biggest promise” (Hulme and Scott 2010). The MDGs consist of eight overarching goals: (1) eradicate poverty and hunger (2) achieve universal primary education (3) promote gender equality and empower women (4) reduce child mortality (5) improve maternal health (6) combat HIV/AIDS, malaria, and other diseases (7) ensure environmental sustainability (8) develop a global partnership for development (see White 2006). The most frequently quoted target is to halve the number of people living on less than a dollar a day, which involves monitoring three social indicators – the proportion of the population below US$1 per day, the poverty gap ratio, and the share of the poorest quintile in national consumption. In total, 48 indicators monitor aspects of well-being and development as diverse as dietary energy consumption, proportion of girls in education, proportion of women in work or political office, child mortality and vaccination, use of contraceptives, prevalence of communicable diseases (HIV, malaria, tuberculosis) and related deaths, aspects of pollution and deforestation, access to water and sanitation, and aspects of global cooperation (aid, trade, debt, access to essential drugs).

Sustainable Well-Being and the Environment Concern for the environment has grown at the local, national, and global levels. The focus on the natural and physical environment (industrial pollution, greenhouse gases, deforestation, land degradation, habitat destruction, changing weather systems, rising sea levels, and water shortages) has also expanded to include the quality of the social and built environments. Many of the debates refer to the limits of growth and consumption in a world of finite natural resources and an expanding population (currently 7 billion, projected to reach 9 billion by 2050) (The projected figure refers to the United Nations’ medium total population estimate (UN-DESA 2011, Table I.1)). A logical reaction has been to advocate sustainable forms of development, although the meaning of “sustainability” has evolved. The original notion of sustainable development refers to “development that meets the needs of the present

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without compromising the ability of future generations to meet their own needs” (Brundtland Report 1987, p. 43). Other concepts endorse sustainable consumption, sustainable living standards, social sustainability, and sustainable human development, inter alia (see Sen (2009, 2013), for example). The conceptualization of “sustainability” has important implications for managing the economy and environment as well as for human well-being. In environmental economics, models of sustainable development typically apply a positive discount rate to the consumption of future generations (e.g., Dasgupta and Heal 1979). Yet it can be shown that optimization may or may not be consistent with sustainability (see Anand and Sen 2000). In practice the connections between the environment and development are complex and run both ways (e.g., Pearce 2006, Fig. 5). Skeptics tend to worry that growth and consumption is “bad” for the environment. An extreme example is Herman Daly’s (2006) notion of “uneconomic growth” which occurs when the costs of growth at the margins are greater than the benefits. A more optimistic view is embodied in the “environmental Kuznets curve” (EKC), which suggests an “inverted u”-shaped relationship between growth and environmental degradation (World Bank 1992). The basic idea is that over the course of a country’s development, a turning point is reached that enables economic growth and technological breakthroughs to solve environmental problems. Critics have responded by questioning the empirical foundations of the EKC and by pointing out that it neglects the high cost of pollution (in terms of foregone wellbeing) already incurred (Pearce 2006, p. 165). Another strand of literature focuses on ways of improving interactions between the environment and human well-being. This increasingly means moving beyond environmental sustainability and conservation by embracing “social sustainability,” namely, “living in ways that can be sustained because they are healthy for people and communities” (Rogers et al. 2012, p. 3). The emphasis on social sustainability permits the inclusion of issues as diverse as crime, forced labor, mental illness, and social status within the environment–well-being dynamic (see Rogers et al. 2012). Knight and Tsuchiya (2008) have categorized some of the linkages between the environment, on the one hand, and physical and mental forms of well-being, on the other. Their dichotomy includes the psychological impacts of landscapes and natural beauty (including the grief experienced following environmental damage), the subjective benefits of living in a clean or safe environment, the advantages of green spaces for physical well-being (“outdoor gyms,” etc.), and the importance of ecosystem services and poverty alleviation (refuge collection, recycling, air quality controls, and support for clean water, fuel, and soil improvement). In practice, the complex linkages between the environment, growth, and human well-being underline the need to carefully and dispassionately weigh the available evidence from a variety of angles and perspectives. Part of the problem is that many environmental costs are either not measured or are overlooked. To fill this gap, Herman Daly and associates have developed an Index of Sustainable Economic Welfare (ISEW) that appears to break the strong correlation between growth and economic welfare previously observed for the United States (see Daly 2006, pp. 655–656). A broader measure (not limited to economic statistics derived from

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national accounts) is the Environmental Vulnerability Index (EVI) which combines fifty environmental, economic, and social indicators in an effort to capture the processes that undermine sustainable development (SOPAC 2005). Although the future of the EVI is uncertain, it does enable direct comparisons between 234 countries.28 Another approach employs a methodology that compares social and environmental indicators before integrating them into a single well-being/stress index covering 180 countries (Prescott-Allen 2001). Yet another approach has the virtue of combining objective, subjective, and environmental indicators (life expectancy, life satisfaction, and the ecological footprint) into a “Happy Planet Index” that tries to monitor sustainable well-being in 151 countries (see http://www. happyplanetindex.org/). One conundrum is the potential conflict between poverty alleviation and environmental protection. This runs along the following lines: the poor need to consume more to achieve sustainable livelihoods and well-being, but greater consumption will place pressure on natural resources and damage the environment. In response, it is sometimes argued that the poor only consume a fraction of the world’s resources (even if their consumption happens to be more costly at the margin). Another argument appeals to the principle of “ethical universalism” which demands impartiality with respect to the opportunities of different people and generations to “live worthwhile lives” (Anand and Sen 2000). This principle implies that the notion of sustainable development “would make little sense if the present life opportunities to be ‘sustained’ in the future were miserable or indigent” (p. 2030). The logic behind ethical universalism can be applied retrospectively too. Arguably today’s poor countries deserve the same latitude and freedom to industrialize and develop that the advanced economies enjoyed in previous generations (some of the chapters in Goldin (2014) touch on similar arguments.). Moving away from traditional concepts of environmental sustainability helps. Anand and Sen argue that “leaving the world as we found it would appear to be neither feasible nor necessarily sensible” (p. 2034). This is because resources can be substituted for one another and what we are in fact “obliged to leave behind is a generalized capacity to create well-being, not any particular thing or particular resource” (p. 2035). The notion of “sustainable human development” embraces this insight and helps address the aforementioned conundrum.29 The human development approach also recognizes that people are agents of change with values and ethical beliefs that enable them to engage constructively with the environment

28

At the time of writing, country ranking only appeared to be available through Wikipedia. The project website includes a useful summary of the EVI, including technical details of the mechanics of the index and a description of the 50 “smart indicators” utilized. (http://www.sopac.org/index. php/environmental-vulnerability-index). 29 The UNDP (2011) suggests that investing in equity is an important step toward sustainable human development for current and future generations.

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(Sen 2009, pp. 248–251; 2013). Above all, the disparate literatures surveyed in this chapter emphasize the need for an account of “comprehensive well-being” (Rogers et al. 2012) that can incorporate physical and mental states (Clark 2002, 2005) as well as notions of sustainability. Acknowledgments I am grateful to Gay Meeks for helpful comments on drafts of this chapter. In writing this chapter, I have benefited enormously from Gay Meeks’ “Philosophical Issues in Economics” lectures at Cambridge University (now part of the MPhil in Development Studies) and from interactions with talented students following this course. I am also indebted to Mozaffar Qizilbash for many helpful conversations over the years. The structure and shape of this chapter has been influenced by the writings of Jim Griffin, Amartya Sen, and Roger Crisp. The usual disclaimers apply. # David A. Clark, 2013.

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Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Caveat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Causes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Marginalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Political Ecology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

While triggered by natural hazards, disasters are never “natural.” The term “natural disaster” is current, universally used, but highly loaded and misleading. Disaster risk is a result of hazard events interacting with people who are prepared or unprepared and who have access to the resources to reduce risk or are deprived of such resources. Keywords

Vulnerability • Capacity • Risk • Natural hazard

B. Wisner (*) Aon-Benfield Hazard Research Centre, University College London, London, UK e-mail: [email protected] M. Fordham Department of Geography, Northumbria University, Newcastle-Upon-Tyne, UK e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_99, # Springer Science+Business Media Dordrecht 2014

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Definition Vulnerability can be defined as “the characteristics of a person or group and their situation that influence their capacity to anticipate, cope with, resist and recover from the impact of a natural hazard” (Wisner et al. 2004, p. 11; Blaikie et al. 2006, p. 30). In its glossary of disaster risk reduction terminology, the UN defines vulnerability as “characteristics and circumstances of a community, system or asset that make it susceptible to the damaging effects of a hazard” (UNISDR 2009). Sasakawa Laureate, Professor Omar Dario Cardona of Colombia, reminds us that “disaster only takes place when the losses exceed the capacity of the population to support or to resist them [and that] vulnerability cannot be defined or measured without reference to the capacity of a population to absorb, respond and recover from the impact of [an] event” (Cardona 2004, p. 43). He goes on to cite a large number of Latin American authors whose writings during the 1980s and 1990s converged on the notion that “vulnerability is socially constructed and is the result of economic, social and political processes” (ibid.). Ordinary people know this. Why else would poor, marginalized Mayans have referred to the 1976 earthquake in Guatemala as a “class quake” (Blaikie et al. 1994, p. 6)? People’s lives are understood by them at the experiential scale of “daily life” and the “quotidian.” Depending on who one is and where one lives and makes a living, daily life presents numerous risks and opportunities. Seasonal flooding in Bangladesh is both risk and opportunity (Schmuck 2012), and for women in Nigeria the grasshoppers that eat cassava (an important root crop) are an opportunity to provide their children with high-protein snacks, while for men these grasshoppers are perceived as a risk to income (Richards 1985). Here we see the way that women, one of the social groups often regarded as vulnerable to hazards, find opportunity in crisis and why labelling people “vulnerable” without acknowledging their capacity for active response can be disempowering and patronizing. Vulnerability and capacity are intimately bound up together in theory and in practice. Capacity can be defined as a set of perceptions (awareness, attitudes), varieties of knowledge and skill, and (of critical importance) access to resources that facilitate people’s ability to anticipate, cope with, resist, and recover from hazard occurrences. Thus, capacity is determined by much more than standard survey measures such as level of education or, in fact, mere income or what is sometimes called “indigenous technological knowledge” or “tradition.” Wisner distinguishes many kinds of local knowledge, including that passed on by elder generations, but go beyond answers to questions such as the When, Where, and How of hazard occurrence (Wisner 2011, p. 325). Besides such technical knowledge (the opportunistic mixing of traditional and modern), he discussed social knowledge that provides answers to the question, “Who is interested in addressing the hazard challenge?” and critical knowledge that is based on the question, “Why are we vulnerable and exposed to the hazard?”

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On occasion, a variety of authors, planners, practitioners, and trainers have found it useful to schematize the relationship among risk (R), hazard (H), vulnerability (V), and capacity (C) as follows (Wisner et al. 2012, p. 24): R ¼ H  ðV=CÞ:

Caveat Vulnerability should certainly not be confused with physical exposure to a hazard. It is often the case that highly vulnerable groups live in locations and on sites exposed to hazards such as steep, deforested slopes, or flood plains. However, less vulnerable people (those with more capacity) living in the same site may have the ability to anticipate, cope with, resist, and recover far better. In New Orleans as Hurricane Katrina approached, people with private vehicles escaped, leaving tens of thousands of elderly, low-income African-Americans and Whites behind. There was no public transportation provided for evacuation (Wisner 2006a). Conflating vulnerability and exposure is a variation of an old theme, the “naturalness” of disaster, which has been attacked for the past 35 years as blaming nature or the victims for the result of social, economic, and political processes that put some people more at risk than others (O’Keefe et al. 1976; Westgate and O’Keefe 1976).

Causes What are those social, economic, and political processes that result in differential vulnerability and capacity? How do those processes interact with environmental processes (ecology, geology, hydrology, climate, etc.)? Within limited space, an overview may be provided in three words: “marginalization” and “political ecology.”

Marginalization Access to resources for development and maintenance of capacity to cope with hazards is critical, as mentioned above. Many processes in society allocate access to resources among different groups and individuals: by caste, gender, or age; by socioeconomic class or inherited and presumptive “rights” to land, water, and pasture; and by the degree of participation in politics, voice, and the ability to enlist use of political power. As a result of these deeply rooted processes, the result is that some people are marginalized: they are caught in what Chambers (1983) once called the “deprivation trap.” They inhabit lands of marginal productivity and dangerous locations (because they have no alternatives and not because they do not perceive the risk), live on economically marginal income (relative to prices), and have little political power or access to those who do (Blaikie and Brookfield 1987; Wisner et al. 2004; 2012). The combination of drought and conflict in Somalia resulted in suffering not

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generically different from mass mortality and lifelong injury from the explosion of the Union Carbide factory in Bhopal, India, in 1984 (Hanna et al. 2005; Jasanoff 1994). In both cases, people sought locations and conducted livelihoods within the constraints of land prices and their access to other resources. They balanced safety and daily bread. Hardscrabble, working-class people lack locational and livelihood options, which keep them in harm’s way – suffering the consequences of mountaintop removal by coal companies in Appalachia (http://mountainjustice.org/facts/steps.php) or unable to flee towns on the Ohio River or in the city of Chester (near Philadelphia) that are chronically polluted by airborne effluents from waste incinerators. They lack the political voice to get regulators to do something about the pollution (http:// www.ejnet.org/chester/kurtz_article.html). Nizamabad district in eastern India has suffered many serious droughts. These have forced some women from poor farming households into the sex trade in the city of Hyderabad, an example of the complex spiral of negative impacts on the lives of women and other marginal groups in disasters (Paul 2012).

Political Ecology The field of political ecology provides a way of framing the interactions of society, nature, and location at a range of scales, from the micro to the macro, within the context of the use and abuse of social, economic, and political power. Political ecology is the grandchild of an approach called human ecology which, from the 1920s onwards, sought to study how human civilization and activities shape the landscape and vice versa. The latter, however, was devoid of an interest in power relations and generally focused on localities (the micro scale) without taking into account what today is called globalization and then should have entered the analysis as the influence of distant decision-makers in colonial metropoles. For example, the Sahel famine in West Africa (1968–1973) was conventionally attributed to drought and population pressure on scarce resources in a naturally semiarid zone. However, the roots of this crisis go back to the introduction of groundnuts (peanuts) by the French colonial powers to have a cheap source of cooking oil for the working class back in France. Groundnut growing spread into zones once occupied by livestock herders. The herders were pushed further into drier areas. The result was catastrophic hunger for both small farmers and herders when the rains repeatedly failed (Franke and Chasin 1980). In the industrial country context, distant bankers and investors, commissars, and Soviet planners made decisions that resulted in twin dust bowls in their respective hinterlands: in the United States in the 1930s (Worster 2004) and in the USSR in the 1950s (Goudie and Middleton 2006, pp. 181–184).

Assessment Many methods for assessment and measurement of disaster risk have been put forward during the 2000s, and that set of operational planning tools continues to

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grow (Birkmann 2006). These range from regional-scale mapping at the global level (Dilley 2006) to a variety of top-down economic and engineering-based measures at the national scale (Cardona 2006) to local scale, participatory assessment in which the affected people themselves organize, map, discuss, plan, and act (Wisner 2006b) – often with facilitation by civil society organizations (Thompson 2012; McCall and Peters-Guarin 2012). The Global Disaster Alert and Coordination System (GDACS) lists 25 sets of tools that are currently being used for disaster risk assessment, including remote sensing, historical analysis, modelling, fault tree analysis, participatory mapping, and a variety of interview methods (GDACS 2012). For example, in the Pacific, volcanologists have worked with local leaders and elders to map eruption and lahar hazards and to overlay these maps onto the mental maps provided by communities showing the time geography of daily life – where people are at different times of day, on different days of the week, and seasonally. Both top-down and bottom-up maps were then used by the residents to design a warning and evacuation plan (Jenkins and Haynes 2012, pp. 342–343). The epistemological elephant in the room is whether one can “measure the un-measurable” (Birkmann and Wisner 2006). Some believe that vulnerability and capacity are sufficiently dynamic and situational that it is impossible to measure them accurately, at least in any meaning of the term “measurement” that would satisfy an engineer or social scientist oriented toward positivism (i.e., the framework that challenges social inquiry to be fully “scientific” on the model of the physical sciences). Others respond from a pragmatic point of view that planners and policy makers and, indeed, local communities themselves need at least surrogates or indices that provide comparable assessments over time and across space (comparing localities and regions). That compromise might, indeed, be the way forward (GNDR 2011).

Conclusion Disasters are never “natural.” There are always root causes to be found by using the tools of political ecology – crudely, “following the money,” or less crudely, analyzing power relations at a variety of scales, from local to global. Vulnerability to hazards – both natural and technological (such as pollution) – is a function of the interaction of hazards, location (exposure), and capacity to anticipate and act to prevent, cope, and recover. Powerful, affluent elites in all societies would prefer to “blame nature” for events that cause great suffering among the poor and marginal with whom they share a territory. Despite having heard a crescendo of scholarly voices contesting the “naturalness” of disaster since the 1970s, it is possible that the discourse of climate change will provide elites with another opportunity to blame nature for disasters. Vigilance is needed to ensure that this does not happen.

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References Birkmann J (ed) (2006) Measuring vulnerability to natural hazards. United Nations University Press, Tokyo Birkmann J, Wisner B (2006) Measuring the un-measurable: the challenge of vulnerability. Source publication no. 5, UN-EHS, Bonn http://www.ehs.unu.edu/file/get/8338 Blaikie P, Brookfield H (1987) Land degradation and society. Longman, London Blaikie P, Cannon T, Davis I, Wisner B (1994) At risk: natural hazards, people’s vulnerability and disasters, 1st edn. Routledge, London Blaikie P, Cannon T, Davis I, Wisner B (2006) Vulnerabilidad: El Entorno Social, Politico y Economico de los Desastres. La Red and ITDG, Lima [Spanish trans: Blaikie et al (1994) At Risk, Routledge, London, p 9] Cardona OD (2004) The need for rethinking the concepts of vulnerability and risk from a holistic perspective. In: Bankoff G, Frerks G, Hilhorst D (eds) Mapping vulnerability: disaster, development & people. Earthscan, London, pp 37–51 Cardona OD (2006) A system of indicators for disaster risk management in the Americas. In: Birkmann (ed) op. cit., pp 189–209 Chambers R (1983) Rural development: putting the last first. Longman, London Dilley M (2006) Disaster risk hotspots: a project summary. In: Birkmann (ed) op. cit., pp 182–188 Franke R, Chasin B (1980) Seeds of famine. Allanheld Osmun, New York GDACS (Global Disaster Alert and Coordination System) (2012) Techniques used in disaster risk assessment. http://www.disasterassessment.org/section.asp?id¼20 GNDR (2011) If we do not join hands: views from the Front Line 2011. GNDR, London. http:// www.globalnetwork-dr.org/images/documents/vfl2011_report/VFL2011_Core_Report_en.pdf Goudie A, Middleton N (2006) Desert dust in the global system. Springer, Berlin Hanna B, Morehouse W, Sarangi S (eds) (2005) The Bhopal reader: remembering twenty years of world’s worst industrial disaster. Other India Press, Mapusa Jasanoff S (1994) Learning from disaster: risk management after Bhopal. University of Pennsylvania Press, Philadelphia Jenkins S, Haynes K (2012) Volcanic eruption. In: Wisner B et al (eds), pp 334–346 McCall M, Peters-Guarin G (2012) Participatory action research and disaster risk. In: Wisner B et al (eds), op. cit., pp 772–786 O’Keefe P, Westgate K, Wisner B (1976) Taking the ‘naturalness’ out of ‘natural’ disaster. Nature (London) 260 (15 April), pp 566–567. [Reprinted and anthologized In: Cutter S (ed) Environmental risks and hazards, Prentice-Hall, Englewood Cliffs, pp 94–96] Paul S (2012) Drought drives rural Indian women into city sex trade. AlertNet (Thomson-Reuters) 3 July http://www.trust.org/alertnet/news/drought-drives-rural-indian-women-into-city-sextrade/ Richards P (1985) Indigenous agricultural revolution. Hutchinson Education, London Schmuck H (2012) Flood. In: Wisner B et al (eds) pp 244–256 Thompson M (2012) Civil society and disaster. In Wisner B et al (eds) pp 723–735 UN International Secretariat for Disaster Reduction (UNISDR) (2009) Terminology. UNISDR, Geneva. http://www.unisdr.org/we/inform/terminology Westgate K, O’Keefe P (1976) Some definitions of disaster. Occasional paper 4, Disaster Research Centre, University of Bradford, Bradford Wisner B, Blaikie P, Cannon T, Davis I (2004) At risk: natural hazards, people’s vulnerability and disasters, 2nd edn. Routledge, London Wisner B (2006a) Hurricane Katrina: Winds of change. In: Ramsamy E, Tate G (eds) The black experience in America. Kendall/Hunt, Dubuque, pp 434–441

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Wisner B (2006b) Self-assessment of coping capacity: participatory, proactive and qualitative engagement of communities in their own risk management. In: Birkmann J (ed) Measuring vulnerability to natural hazard: towards disaster resilient societies. UNU-Press, Tokyo/New York/Paris, pp 328–340 Wisner B (2011) Environmental justice, health, and safety in urban South Africa: Alexandra township revisited. In: Johnston BR (ed) Life and death matters, 2nd edn. Left Coast Press, Walnut Creek, pp 311–332 Wisner B, Gaillard JC, Kelman I (2012) Framing disaster. In: Wisner B, Gaillard JC, Kelman I (eds) The Routledge handbook of hazards and disaster risk reduction. Routledge, London, pp 18–33 Worster D (2004) Dust bowl: the southern plains in the 1930s. Oxford University Press, New York

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Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What Is a Disaster? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Emergence of Disaster Risk Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . From “Civil Protection” to “Disaster Management” to “Disaster Risk Reduction” . . . . . . Disaster Reduction as Development and Vice Versa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DRR from the Top Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Hyogo Framework for Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Problems with Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DRR from the Bottom Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2015 and Beyond . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Known and the Unknown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

With historical roots in the command and control approach of “civil defense,” disaster management (DM) has grown ever more “civilianized” as the old military model has evolved into one that engages citizens. In turn, DM has moved increasingly from dealing only with response to events and recovery to proactive attempts to prevent or at least reduce the potential losses. This approach is called “disaster risk reduction” (DRR). However, implementation of this fine ideal faces numerous problems. So far in the hands of a UN agency, globalization of DRR has not had the desired results.

B. Wisner (*) Aon-Benfield Hazard Research Centre, University College London, London, UK e-mail: [email protected] M. Fordham Department of Geography, Northumbria University, Newcastle-Upon-Tyne, UK e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_56, # Springer Science+Business Media Dordrecht 2014

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Keywords

Disaster risk reduction • Decentralization • Participation • Citizenship • Hyogo framework for action

Definition What Is a Disaster? Human life is filled with uncertainties and risks. Some of these gain political salience and visibility to planners and policy makers in governments, international and UN agencies, and a variety of civil society groups and scientific think tanks. Risks such as traffic fatalities – although on a national basis in some countries they can number in the tens of thousands per year – generally have not been defined as a “disaster.” No one in the USA compares the lives lost in the World Trade Center attack (around 3,000) with the number killed each year on US roads (about 40,000). Likewise very high maternal mortality is seldom called a “disaster” (Index Mundi 2012; Newar and Sharma 2006). Rather than engaging in the messy question “what is a disaster?” (Quarantelli 1998), we will simply address the common denominator recognized in policy, planning, and practice communities: a disaster is a crisis in a place involving loss of ten or more lives and loss of property that requires assistance, from either an adjacent jurisdiction, national government, or an international declaration of emergency (EM-DAT 2012; compare UNISDR 2009). We would add to this fairly standard definition the disruption of people’s livelihoods (see chapter on ▶ Vulnerability and Capacity).

The Emergence of Disaster Risk Reduction From “Civil Protection” to “Disaster Management” to “Disaster Risk Reduction” Disaster risk reduction (DRR) is the desired outcome of policy, planning, and practice dedicated to reducing the vulnerability of people and their livelihoods, increasing their capacity to cope with extreme natural events (hazards), and putting in place policies and practices that facilitate vulnerability reduction and enhanced local capacity to cope (sometimes called “resilience”). DRR is a relatively recent concept and practice. From the end of World War II through the 1960s, societal planning for disaster took a centralized “command and control” approach based on military and paramilitary institutions (“civil defense” or “civil protection”), much of this driven by the threat of nuclear war during the 1950s and 1960s. Civilian disaster management (DM) began to emerge in the 1970s and 1980s in varying degrees in different parts of the world. Connections with environmental management, social services, and urban planning were tentatively made.

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DRR is supposed to take DM a step further by involving local communities and institutions of local government in assessing their own likely hazards and their resources and capabilities as well as vulnerabilities in relation to those locally prevailing hazards. DRR began to develop seriously from the mid-1990s and the midterm review of the UN’s International Decade for Disaster Reduction.

Disaster Reduction as Development and Vice Versa During the 2000s there has been a growing concern with an integrated and comprehensive approach to disasters that sees them not only within the purview of a specialized kind of agency but as continuous and intermingled inseparably with the local impacts of climate change and adaptations to climate variability, as well as intimately linked with environmental management and protection and economic, social, or human development. In most places, however, governments still tend to house these four sets of “problems” (and consequent activities, budgets, and human resources) in separate departments or ministries, usually with little coordination or cooperation among them. This has become known as the challenge of breaking down the boundaries of such “silos.”

DRR from the Top Down The Hyogo Framework for Action The global meeting on disaster risk reduction held in Kobe, Japan, was to coincide with the 10th anniversary of the Great Hanshin Earthquake of 1995 that had killed 6,000 and done US$ 120 billion damage to the city (Witherell 2011). It would have been a run-of-the-mill diplomatic and scientific talk shop had it not been for the timing. It took place less than a month after the catastrophic Indian Ocean Tsunami (“Boxing Day,” 26 December 2004). Many of the international agency and INGO participants came directly to Kobe from first response and assessment activities in the affected parts of Indonesia, Sri Lanka, India, and elsewhere. This introduced a sense of urgency. Nevertheless, the national representatives in their diplomatic sessions (not open to the public or other participants) negotiated a generally worded agreement that was not only nonbinding but which did not even specify concrete targets. Its compassionate though fuzzy headline goal was a “substantial reduction of disaster losses, in lives, and in the social, economic and environmental assets of communities and countries.” The agreement signed in Kobe was called the Hyogo Framework for Action (HFA). It defines five priority areas. Under each there are a series of nonbinding guidelines (http://www.unisdr.org/files/8720_summaryHFP20052015.pdf): 1. Ensure that disaster risk reduction (DRR) is a national and a local priority with a strong institutional basis for implementation. 2. Identify, assess and monitor disaster risks and enhance early warning.

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3. Use knowledge, innovation and education to build a culture of safety and resilience at all levels. 4. Reduce the underlying risk factors. 5. Strengthen disaster preparedness for effective response at all levels.

Problems with Implementation The problem with the HFA is not just conceptual – uncritical use of vague notions such as “culture of protection.” In fact, despite a total blind spot where it comes to what some believe to be the fundamental or root cause of disaster vulnerability, namely, access to resources and political power, each of these five priority areas does have some actionable, concrete implications. However, where it comes to implementation, the HFA and its custodian, the UN’s International Strategy for Disaster Reduction (UNISDR), are at the mercy of national elites, their material interests, and the internal politics in countries that influence what happens at subnational and local scale.

Diplomatic Immunity The UNISDR is diplomatically set up not to criticize member countries of the UN. It advises, advocates, and cajoles, but it does not directly monitor compliance with the HFA. It gets national reports on implementation of the HFA every 2 years, but the UNISDR does no fact checking. Whatever member countries report is what the UNISDR publishes. Decentralization For decades various UN agencies have called for decentralization of central government systems for disaster reduction. Departments in ministries exist; workshops and conferences are held at national and international level; bureaucrats are employed; laws are passed. But the impact on the risks run by ordinary people in villages and urban neighborhoods is little affected. The UNISDR merely assumes that decentralization is a fact – an achievement it can build upon. The reality is different. In many countries, there may be legal or formal decentralization of some functions, but if one “follows the money,” there is not a corresponding flow of resources downward through the system of governance. The HFA is laced with references to actions “at all scales,” but local government in particular often does not have the financial or technical resources required to implement the HFA. However, on the positive side of decentralization, more than 150 cities have signed up for a disaster reduction campaign that involves ten essential elements. Among them are Mexico City (Mexico), Durban (South Africa), Bogota (Colombia), Port-au-Prince (Haiti), Amman (Jordan), Albay and Cebu (the Philippines), Cairns (Australia), Chennai City (India), Colombo (Sri Lanka), Dhaka (Bangladesh), Kathmandu (Nepal), and Saint Louis (Senegal) (UNISDR 2011a).

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The “ten essentials” include coordinating with citizen groups, maintaining a hazard database, budgeting for DRR, protecting critical infrastructure including schools and health facilities, enforcing building codes, and protecting the natural environment (UNISDR 2012).

Community Participation Since at least 1994 and the first World Conference on Natural Disaster Reduction in Yokohama, Japan, there has been lip service paid to “community participation” in DRR. Communities feature prominently in the HFA. Yet what actually constitutes “participation”? The HFA has a low threshold. Research has revealed a “ladder of participation” whose lower rungs include mere “consultation” (Hart 1992; Arnstein 1969). The government plans to do something and comes along to inform residents of a locality, possibly fine-tuning according to their input. As one ascends this “ladder,” communities themselves are increasingly proactive and control more and more of the decision-making. Another way of thinking about this range of approaches is the bipolar “instrumental” versus “transformative” participation (Wisner 1988). At the transformative end of the spectrum, citizenship may be actualized in the form of participatory budgeting (PB), for example, where communities decide how to spend tax revenue and which infrastructure projects to prioritize (Participatory Budgeting Project 2012). This obviously can have a large influence on the impacts of hazards such as floods, landslides, earthquakes, and droughts. PB began in Porto Alegre, Brazil, but has now spread to other cities. Deeper Problems Returning to the concepts contained or implied by the Hyogo Framework for Action, deeper problems are revealed that would limit whatever was implemented, even if there were genuine “political will” at the national level and even if there were concrete targets and international monitoring of compliance. As hinted above, and as is made clear in the chapter on Vulnerability and Capacity, the fundamental, root cause of vulnerability to extreme natural events is the distribution of access to resources and political power in a society. Where people do not have access to land, water, markets, credit and safe locations, there is little they can do to avoid harsh impacts by extreme climate-related events such as drought, flooding, landslides, and coastal storm surges. The same is true as regards geophysical extremes such as earthquakes, tsunamis, and volcanic eruptions. The HFA does not touch issues of resource distribution or economic and political power when it conceives of “underlying risk factors.” The UNISDR lists 11 areas of action under this one priority – everything from “sustainable ecosystems and environmental management” to “protection of critical public facilities” – but there is no mention of access to resources or the role of political power in society. Far from recognizing the elephant in the room – societal distribution of access to resources and the distribution of economic and political power (main determinates of the ability to influence policy) – the HFA lists things such as “food security” that in turn are dependent on resources and political voice. Recent data from India

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shows that governments are only rewarded by voters if they are seen to be generous and efficient in providing disaster relief in the year before an election (Cole et al. 2012). However, the whole point of the HFA is to talk national governments round to investing in long-term prevention of disastrous consequences of hazards. Where is the motivation for governments to do that if voters do not seem to reward them for such investments?

DRR from the Bottom Up An alternative or perhaps complementary way of looking at DRR and its practice has emerged since the 1990s, as international and national NGOs and community-based organizations (CBOs) have become more active in preventing disaster or limiting (mitigating) the impacts of natural hazards rather than merely responding and attempting to assist in recovery. The approach is generically known as communitybased disaster risk reduction (CBDRR), although there are as many specific names and methods as there are practicing institutions. The approach involves working with communities as they define and map their own hazards and work through strategies for warning and for reducing possible impacts. Often this results in an action plan that is initially funded externally. For example, in Honduras, local systems of flash flood warning have been developed in which upstream residents monitor streamflow and report it to a center in the downstream town, where laptop-based models provide forewarning of likely flash flooding (IFRC 2006). Residents (who have earlier worked out evacuation routes and conducted drills) are alerted. Many lives have been saved. A very large body of experience with CBDRR has been built up over 20 years (see http://www.proventionconsortium.org/?pageid¼39 and http://www. preventionweb.net/english/themes/community-drr/). However, there are challenges to mainstreaming this bottom-up approach. First, there are deep-seated biases inherited by urban and educated administrators against what they perceive as the “superstition” and “ignorance” of ordinary people, especially the poor (Wisner 2010). Second, even when mutual respect has been established, there are many questions about what “community” actually is: who local elites are, who the invisible and voiceless residents might be, etc. Third, there are serious issues concerning power that inevitably emerge in the community-NGO relationship despite the use of the feel-good language of “partnership.” Fourth, even where care is taken to devolve responsibility and to practice “downward accountability” on the part of the NGO or INGO, the logic of the “project cycle” usually limits involvement to too short a time to fully root the initiative in the local community. Finally, overlapping all of the above are issues of economic sustainability. Once established, how will a bottom-up scheme be funded? This is especially salient in situations where local governments do not receive much support from the center and do not have many sources of income or statutory ways of raising their own revenue.

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2015 and Beyond In 2015 the Millennium Development Goals should have been attained as well as the delivery of “substantial reduction” of disaster losses under HFA. Already various stakeholders are busy drafting “post-HFA” and “post-2015” plans. Meanwhile, life is what actually happens while planners plan. Climate continues to change. Cities continue to grow. Forests and other natural resources continue to be despoiled by forestry, mining, and agribusiness interests. Small farmers and pastoralists continue to be displaced by “land grabs.” Money continues to accumulate in the Swiss bank accounts of corrupt politicians. It is also well known that the HFA’s recommended actions have simply not been “trickling down.” The Global Network of Civil Society Organisations for Disaster Reduction (GNDR) conducted two large-scale surveys at the local level in 2009 and 2011 that documented the failures of trickle-down or top-down “diffusion of innovation” (GNDR 2009, 2011). These last mentioned are deceptive paradigms, and the results speak for themselves. The second of these “Views from the Frontline” (VFL) surveys was based on 20,000 interviews in 69 countries and yielded statistically significant results (GNDR 2011). What governments report to the UNISDR and what local community representatives and local government officials report are worlds apart. While in the UNISDR’s Global Assessment Report (UNISDR 2011b) over half (48 of the 82) of the national governments self-reported “substantial or comprehensive” progress on risk governance indicators, none of the 69 countries participating on the VFL survey reported “substantial” progress at the local level (GNDR 2011, p. 31).

The Known and the Unknown All the above fall under the category of what one knows. The IPCC’s (Intergovernmental Panel on Climate Change) thorough study of extreme climate events and climate change emphasized the clarity that has been achieved since the first of the IPCC reports was published in 1990 (IPCC 2012). An unknown is what political upheavals and other changes and economic trends will interact with the “knowns” in the post-2015 world, affecting disaster risk. Conflict, climate change, fate of the euro and the US dollar, and the role of the rising economic powers such as the BRIC countries (Brazil, Russia, India, and China) are the major unknowns in the humanitarian and human development landscape. Unknowns introduce uncertainty, adding to the challenge of post-2015 DRR. Who before 2011 would have imagined the combination of earthquake, tsunami, and a cascade of nuclear accidents in Japan? While we know a very large amount about climate change and likely extreme climate events, what surprises await? In the face of these unknowns, it is all the more important that capacity for knowledge management and iterative planning be developed at the local

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government scale in partnership with communities. The HFA has not come near to putting such capacity in place. Might the UNDP, with its explicit focus on development, or some other configuration of agencies do better?

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Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Drivers of Pollution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Incentives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Eliminate Environmentally Harmful Subsidies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Technology Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Performance Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Incentive-Based or Economic Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

This chapter examines the drivers and incentives behind pollution emissions and pollution control. Ecosystem services tend to be produced from common pool resources, which are depletable and difficult to exclude users from, rather than other classes of resources. These characteristics are some of the main reasons we have such trouble managing valuable natural resources. Recognizing that strong incentives exist to degrade environmental resources and also free-ride off those who protect them is therefore a key starting point for improving environmental protection. Keywords

Common pool resources • Public goods • Pollution • Pollution control • Economic instruments

R. Bluffstone Department of Economics, Portland State University, Portland, OR, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_57, # Springer Science+Business Media Dordrecht 2014

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Definition Environmental resources have particular characteristics that make them difficult to manage and cause them to be subject to degradation. Recognizing these perverse incentives and devising ways to overcome them are therefore critical to successful environmental protection.

Introduction This chapter focuses on the economic forces and incentives that generate excessive pollution. It also discusses the possibilities for using incentives to mitigate pollution emissions and damages. The approach presented is standard in the economic literature and examines pollution drivers and solutions as microeconomic problems that are treatable at the individual, firm, and market levels. While standard in the economics literature, others have treated pollution issues very broadly, including focusing on population and economic output. We will briefly consider these alternative approaches in the conclusion to this chapter. From the perspective of economics, which looks at the world through the lens of resource use by humans (including production and direct enjoyment), pollution can be analyzed as either a bad or good thing. Pollution can be bad, because pollution is at its essence an extra cost imposed on the world by those engaged in economic activities. To use a classic example, pollution from a steel plant imposes additional cleaning costs on nearby laundries (Coase 1960). Of particular urgency today are the climate stability costs coal-fired power plants impose on the world. Such costs are often referred to as negative externalities and this way of thinking about pollution accords very well with many negative conceptualizations. It also corresponds well with analyses that focus on production and consumption as the root of pollution problems, because in this framework optimal production and consumption are always lower when externalities are internalized. But often a more useful way to think of “pollution” is that it is merely a pejorative term for the waste-assimilating services provided by the environment. The notion that the environment provides a variety of services to humans dates back at least to Krutilla (1967), but the idea really came to the fore as a result of the Millennium Ecosystem Assessment (2005). Services discussed in the Assessment include supporting, provisioning, regulating, and cultural (MEA 2005). Waste assimilation services are also mentioned in the Assessment and with good reason. It certainly would be inconvenient, not to mention costly, if one morning we all woke up and the environment no longer accepted our waste. How would those of us who drive cars get to work? What would we do with our garbage? With current technologies, how would we provide electric power on the same level as is currently available? Cast in this way waste disposal is just one of the many valuable ecosystem services the environment provides. The problem, of course, is that this service conflicts with other services environmental assets can provide. For example, disposing wastes into the air conflicts

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with the human health-providing services of clean air; clean air helps us avoid bronchitis. Using the air as a place to put our waste also conflicts with the service clean air provides to allow us to see long distances, impairing our view, etc. That such conflicts exist are unfortunate, but we should recognize that conflicts in use and the requirement that we give up something when we make choices about resource use are all standard fare. These principles apply equally well to buildings that cannot simultaneously be used for schools and houses, buses that cannot be used as food carts if they transport children to school, and environmental assets like forests, clean air, and lakes. What makes environmental assets different is that often uses are irreversible. For example, if a forest is used for timber, the biodiversity services of forests may be lost forever. The loss of one plot of forests may also affect biodiversity on other plots. These are features that are peculiar to environmental assets and services that are typically not present for standard capital. Such features can make environmental management especially tricky. Using the waste assimilation capacity of the environment to dispose wastes is typically considered inevitable as long as production and consumption of desirable goods and services carry with them wastes that must either be disposed or mitigated at high cost. Such conditions indeed in general make emissions of environmentally damaging wastes in some sense “optimal.” For example, suppose a product is particularly valued by society and at the relevant emission levels intertemporal environmental damages are low and abatement costs high (goods that are produced in competitive markets are typically valued using market prices, because they reflect the scarcity and opportunity cost associated with producing those goods. For goods like environmental services, public education, and public safety for which we typically do not have markets, prices do not exist. Determining those goods’ values is therefore more complicated, but the basic principle that they can be valued and weighed against any pollution produced is not dependent on the existence of prices). Under such circumstances, it clearly makes sense to emit some and perhaps a lot of pollution. An example could be carbon emissions from a fossil fuel power plant in a developing country city experiencing power grid brownouts. As of 2012, such cities include Addis Ababa, Kathmandu, and Kinshasa. Of course, we need to add some caveats. First, the above discussion does not consider the distribution of costs and benefits associated with pollution emissions but treats communities as a whole (indeed, finding reasonable ways to weigh the different parts of society who gain and lose from pollution emissions is surprisingly difficult). This can be a problem if the benefits of pollution or pollution reduction are concentrated, but the costs are dispersed. A fossil fuel-powered factory or power plant emitting carbon that affects the climate would be a common, but also poignant, example of pollution benefits being concentrated, but costs dispersed. In recent decades environmental justice concerns have come to the fore in which people worry that environmental amenities like parks and clean air are concentrated in affluent areas, while costs are spread across communities. Second, there is no reason to believe that all pollution and certainly not all levels of pollution should be emitted, because one can concoct alternative examples in which environmental damages are very high, abatement costs low, and product

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value low. An example would be crops grown with subsidized chemical inputs and underpriced water that emit high levels of pollution and harm endangered aquatic species. Under such circumstances, perhaps such crops should not be grown at all; even without considering environmental effects, the world could be a better place without the crops (if a product is highly valued, without imposing normative judgments on others’ consumption choices (e.g., transportation choice), finding examples where the optimal pollution level is no pollution is quite hard).

The Drivers of Pollution So the real question is not whether pollution should exist or whether we need to give something up to use the waste-assimilating services of the environment, but why might those services be overused relative to other uses? The answer has to do with the nature of environmental assets and the services they provide, as well as the awkward incentives that tend to be associated with environmental services. Goods and services may be categorized along two dimensions. The first is the degree to which they deplete as they are used – that is, can we all use a good simultaneously without interfering with each other (sometimes called rivalry in consumption)? The second dimension is excludability – is it technologically possible to exclude people from using or consuming a good? Table 97.1 presents these dimensions in the form of a matrix along with examples. The bottom right quadrant presents goods that are neither excludable nor depletable. These are classic public goods that once created do not deplete and users cannot be excluded. Such goods, if they are not created by nature, are generally provided by local, regional, and national governments. The top left quadrant includes goods that are both excludable and depletable. Another name for such goods is private goods, which encompass mostly all the goods we buy and sell on a daily basis. Examples include paper and computers, toothpaste, oil, pottery, tax preparation services, and massages. All these goods have the property that it is technologically possible to keep people from getting them, and only one person can enjoy them at a time. Such goods are highly compatible with market economies driven by profit opportunities. Such characteristics are very convenient for a number of reasons related to enforcement of what are typically referred to as “property rights” (Ostrom 1990). For example, excludability assures that those who are unwilling to contribute resources to provide a good will not get it; to get the good one must pay his/her way. Depletability/non-rivalry then assures that the user community is selfpolicing. Once such goods are created and “bought,” users defend their property rights, but producers need not be involved; with depletability, property rights – and the burden to defend them – pass from producers to consumers. At its most basic level, governments need not even be involved except perhaps to enforce contracts. Excludability and depletability assure that users cannot free-ride off the sacrifices of others and that the people who provide goods valued by the community can capture the benefits. Entrepreneurs will therefore be quite interested in providing

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Table 97.1 Types of goods Depletable

Not depletable

Excludable Private goods (e.g., massages, televisions, accounting services, toothpaste, paper, computers) Club goods (e.g., DVDs, CDs, books, education, movies in a theater, small parks, large swimming pools, roads)

Non-excludable Common pool (e.g., climate stability, flood protection from forests, coastal zone services, aquifers, biodiversity) Pure public goods (e.g., street lights, sunlight, ideas, news, music, national defense)

private goods and to some extent will also be involved in club goods, which are excludable, but not depletable. For example, the private sector actively competes with public schools and is very involved with creative industries like movies, books, and music. When excludability is difficult (e.g., music, news) there is a tension and the private sector takes steps to improve excludability. Cable television is an important example. As shown in Table 97.1, environmental goods tend to be common pool goods that can be degraded and are difficult to exclude. Environmental services and the assets that produce them therefore can degrade over time, particularly as more people draw on these resources under conditions of non-excludability. Such a combination of characteristics – depletability and non-excludability – is very unfortunate and represents the number one reason we struggle with environmental problems. A key way environmental assets like clean air, natural coastlines, underground aquifers, and forests are degraded is through pollution. Non-excludability makes excessive degradation almost inevitable, because pollution is linked to private goods production that individuals, households, and firms can fully appropriate. For example, diesel-powered trucks use the waste assimilation capacity of the air to produce incomes for trucking company owners, drivers, and laborers. These incomes are then converted into real goods like food, entertainment, computers, and services like music lessons. Without drawing on the waste-assimilating properties of the air, a critical input into trucking would be missing. Without controls, overuse is virtually assured.

Incentives Because environmental assets degrade and are held in common, there are always potential incentives for people to pollute “too much,” impose costs on others, and therefore save themselves money (this conclusion follows from any model assuming that individuals and firms work primarily to benefit themselves). Altruism, fairness, and desire for reciprocity are certainly key elements of economic behavior. These characteristics often keep polluters from emitting as much pollution as pure self-interest might dictate, but they are unlikely to completely offset self interest. The problem, of course, is that over-polluters excessively degrade other services provided by the air, such as climate stability, good views, and human health

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protection. There is therefore a need to bring polluters’ incentives into line with those of the broader society. The insight that the challenge is to align individual and societal incentives dates at least back to the 1920s when the French economist A. C. Pigou proposed that taxes be used for this purpose (Pigou 1952). Of course, incentives may be more complex than simply short-run personal gain. Individuals and firms often are altruistic or they may worry about their long-run reputations. Such issues complicate our behavioral model but probably do not undercut the fundamental conclusion that the overall society is likely to want less pollution than those who demand the waste disposal services of the environment. Imposing solutions to properly align incentives is often difficult, however, because benefits of pollution may be quite concentrated (e.g., within the trucking industry), but the costs are dispersed (e.g., across a whole city). Furthermore, the benefits of pollution are always fairly easily expressed in monetary terms or other standard economic metrics like jobs created. Costs of pollution like health effects, biodiversity loss, or reduction in swimming days are, by contrast, often very difficult to express in monetary terms (that said, an enormous literature on valuation of nonmarket goods has emerged during the past 30 years. For a discussion see Freeman (2003)). Environmental services other than waste assimilation services are therefore inherently at a disadvantage. There are four main ways to reduce incentives to overuse the waste-assimilating services of the environment. These methods are (1) elimination of environmentally harmful subsidies, (2) technology standards, (3) performance standards, and (4) incentive-based or economic instruments. Virtually all of these methods involve local, regional, and national governments, which across the world are our main institutions for coordination related to pure public, club, and common pool goods. In addition to coordinating on the environment, governments are also our main vehicle for coordinating around other important social problems like product safety, road safety, homelessness, crime, mental illness, and antipoverty efforts.

Eliminate Environmentally Harmful Subsidies It may be hard to believe, but around the world governments offer individuals and businesses a variety of subsidies that directly or indirectly encourage pollution. The first instrument to employ is therefore the elimination of environmentally harmful subsidies. Subsidies in general are to be viewed with caution, because they change incentives and if large and important enough can steer economies in directions that bear little resemblance to their areas of advantage. For example, rice subsidies in a food-deficit country drive down rice prices and stimulate rice consumption. This may be occurring when in fact international rice prices are high and the country has no advantage in (and may not even produce) rice. Local producers of substitute grains (e.g., wheat) then find their prices depressed, because consumers have switched to rice and they therefore plant less wheat; the absolutely wrong signals about rice and wheat scarcity are therefore given to consumers and producers.

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Perhaps the most pernicious environmentally harmful subsidies are those applied to energy, because energy overuse can have such serious environmental impacts. Energy is typically produced by burning fossil fuels, such as coal, oil, or natural gas, which in the burning process generates air pollution. Energy is also a critical input into a variety of economic activities. Such subsidies – and their side effects – once they are introduced therefore have a way of pervading many economic sectors. Perhaps the most important example of energy subsidies run amok was in the Soviet Union and its allied countries. Fed by energy prices that were state controlled, set to encourage use of the abundant energy resources of the Soviet Union and bearing little resemblance to scarcity values, these countries were some of the most energy intensive in the world. For example, the energy intensity of Poland (in kg oil equivalent/$US GDP) in 1980 was roughly three times that of France. Across Central and Eastern Europe, energy intensity was roughly twice that of the OECD. These low energy prices then spawned a variety of economic and environmental effects. For example, certain energy-intensive and highly polluting sectors of the economy like steel and cement became outsized compared with other countries. In the 1980s the Soviet Union produced 15 times the steel of the United States per $US of GDP. To support this commitment, the country had twice the steel production capacity of the United States with an economy 1/8th as large (Sachs 1997). To western European and American eyes, Central and Eastern Europe and the former Soviet Union often still feel as if too great a use is made of steel and cement. The overuse of energy and distorted economic structure created very high pollution levels and serious environmental and human health problems. For example, East Germany produced more than four times the SO2 of France, 15 times the emissions per capita, and 30 times the emissions per $US of GDP (French 1990). The same was basically also true for Poland and Czechoslovakia. As a result, the area where these three countries intersected came to be known as the “Black Triangle.” In the Black Triangle pollution concentrations sometimes were over ten times the World Health Organization limits, and much greater incidences of a variety of diseases were documented. All this was possible only because of energy subsidies.

Technology Standards Technology standards specify the technologies firms, households, and markets must use to meet legal environmental requirements. This approach is very prevalent, at least partly because it is understandable and monitoring is relatively easy (Sterner 2003). Technology standards are very important for regulating pollution from vehicles and in the United States date from the 1970s. Examples of such instruments include requirements to use lead-free gasoline, low sulfur diesel, and catalytic converters that reduce smog-inducing nitrogen oxide emissions. Other examples include requirements that industrial facilities

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and municipalities have wastewater treatment plants with specific technical features. Primary and secondary treatment would be examples of such requirements.

Performance Standards Performance standards do not specify specific technologies but instead identify pollution standards that are consistent with environmental objectives. Examples include requirements that power plants limit SO2 or particulate emissions to 0.5 mg/m3 and food processing firms limit BOD emissions to 25 mg/l. Performance standards are potentially preferred to technology standards all else equal, because they offer polluters more compliance flexibility regarding how to meet environmental outcomes. Flexibility is desirable, because polluters can choose from all possible technological options rather than just the ones approved by regulators. Having options creates incentives for polluters to find cheaper and better ways to reduce emissions. At any point in time, costs are lower than when technologies are specified, and over time incentives to develop better technologies are created. Such dynamic incentives can be expected to further lower costs or allow more environmental protection to be accomplished for a given set of investments. If they are higher cost, why then are technology standards used at all? Technology standards are most appropriate when monitoring of pollution emissions is difficult. Vehicles are an ideal application – though in coming years technological change may force a revision of that conclusion – because it is difficult to monitor vehicle maintenance and driving behavior. These factors typically have been important determinants of vehicle emissions, but since they are largely unobservable, technological requirements stand in for measurements of emissions.

Incentive-Based or Economic Instruments But even performance standards may be considered relatively rigid if broader measures than firm, facility, plant, or source-level pollution are most relevant (for simplicity from now on such lower-level pollution units will be referred to as facilities). For example, if the regulatory objective is to control air pollution emissions in a particular airshed, perhaps performance standards should be at the airshed rather than facility level. When higher level controls are most appropriate, higher degrees of flexibility can be offered that further drive down costs and increase incentives for technical change. Some instruments do not require that facilities even meet emission requirements as long as other facilities compensate (the literature on incentive-based, market-based, or “economic” instruments for pollution control is enormous and will not be truly overviewed in this short chapter. For more information, please see Thomas Sterner’s excellent volume on policy instruments (Sterner 2003.)).

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For example, pollution charges, which charge per unit of pollution emitted, are widely used in China and Europe. Though many variations exist, pollution charges often do not even specify upper pollution bounds (Bluffstone 2003), but on the other hand, they also provide incentives to drive pollution as low as possible, given the charge level. Pollution charges also generate revenues that are typically earmarked for environmental protection. Sometimes for technical reasons, it is infeasible to charge based on pollution emissions. In such circumstances charges are often levied on polluting products like plastic bags, tires, gasoline, natural gas, and electricity or on the polluting content of inputs. For example, governments may charge for pollution from burning coal based on the sulfur and dust content of the coal used. These types of charges are the most common environmental charges used in Europe and the United States. Environmental charges vary widely across countries but are typically a low percentage of government budgets (Sterner 2003). Pollution trading is an important incentive-based, flexible alternative to environmental charges. Sometimes called cap-and-trade, pollution trading specifies the total allowed pollution, allocates those allowances through a variety of methods depending on the system, and then allows polluters to trade their rights to pollute. This instrument offers a key advantage over environmental charges, because the overall emissions are fixed. Regulators therefore can be confident that overall goals will be reached, but due to the opportunity to trade the burdens of pollution, reduction will be allocated as cost effectively as possible. The US acid rain program was the first to demonstrate the efficacy of such an approach. It is credited with reducing SO2 emissions from regulated sources by 40 % and NOx emissions by 50 % during the period 1995–2007. The program also dramatically reduced compliance costs while generating an estimated $142 billion in benefits from $3.5 billion spent on compliance (Napolitano et al. 2007). Cap-andtrade is also used in Europe to control carbon emissions, and a law initiating a carbon trading program was recently approved in California (for details on the California program, see the California Air Resources Board website at http://arb.ca. gov/cc/capandtrade/capandtrade.htm. For information on the European Trading Scheme, see http://ec.europa.eu/clima/policies/ets/index_en.htm). Information can also be used to control pollution emissions. The US Environmental Protection Agency publishes the toxic release inventory, which publicizes the emissions of 600 toxic chemicals from large facilities in the United States. Participants in markets like the stock market know that toxic emissions can sometimes trigger litigation and often signal inefficient production methods. Evidence suggests that because of the TRI firms try to reduce their emissions to avoid appearing as major emitters (for more details on the Toxic Release Inventory, see http://www.epa.gov/tri/). In developing and transition countries, where monitoring and enforcement capacity are even more scarce than in the developed world, information-based incentive mechanisms are particularly important. Indeed, in two coauthored published papers, I found that firms in Central and Eastern Europe more readily

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Table 97.2 PROPER program ratings Rating Gold Green Blue Red Black

Requirements World class technology. Waste minimization/pollution prevention Above legal standards. Good maintenance and management Complies with environmental limits Below legally required limits Serious environmental damage caused. No pollution control efforts

adopted environmental management systems like ISO14001 if information about their pollution emissions was publicly available. The PROPER program in Indonesia utilizes information to particular advantage. It uses simple environmental ratings to give the public information on the environmental performance of firms. As shown in Table 97.2, firms can get five rankings ranging from gold to black. These rankings are given by government inspectors and publicized. Evidence suggests that firms that have low rankings are motivated to increase their rankings at least to blue level. Movements from blue to green and gold are less common (Sterner 2003).

Conclusions This chapter examined the drivers and incentives behind pollution emissions and control. That environmental goods tend to be a common pool rather than one of the other three types of goods is the main reason we have such trouble managing and preserving valuable natural resources. Recognizing that strong incentives exist to degrade environmental resources and also free-ride off those who protect such resources should be a key starting point for improving environmental protection. How to reduce pollution to appropriate levels? Common pool resources are typically subject to government control and therefore political processes. Efforts to contain pollution will always be at a disadvantage vis-a`-vis uses of the environment for waste assimilation, because while the costs to reduce pollution may be well known, environmental goods tend to not be marketed and therefore we are unlikely to know the unit value of environmental assets. Furthermore, we may even have difficulty measuring environmental services. Suppose problem-free breathing is a key service from air with less SO2. What would it take to measure this service? We first need to know how much a reduction of, for example, 1,000 t of SO2 per year in an airshed reduces atmospheric SO2 concentrations. Such estimations can be done but are involved. Supposing we know that the reduced emissions will reduce concentrations by 1.5 mg/m3, how many incidents of asthma, bronchitis, and coughs will be eliminated? What are the values of those incidents? These are answerable questions, but they are much more difficult to answer than the question “how much does it cost to install flue gas desulfurization that will reduce SO2 emissions by 1,000 t?”

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The trick then is for policymakers to create regulatory structures in which polluters have incentives to optimize pollution emissions in line with social values. Because pollution abatement truly can be expensive and societies become more and more ambitious about environmental protection over time, there is also an urgent need to create incentives for cost-effective reductions and technological change that will push costs down over time. Incentive-based economic instruments try to increase environmental protection cost effectively. To the extent possible they seek to create incentives for polluters to search for innovative pollution reduction methods and implement only those that are worth doing. Often discussion of these instruments refers to “getting the prices right,” because they try to mimic the price incentives of market systems. An obvious example is pollution charges, which “price” pollution. Sometimes – as in the case of information-based voluntary pollution control systems – the government can play a fairly limited role, because firms have strong incentives to reduce pollution. Often, though, such incentives are not sufficient to protect key environmental services and more proscriptive measures like technology standards and emissions limits are needed. In general, therefore, a combination of instruments is required to be sure a rich variety of services are provided by environmental assets. This chapter briefly summarizes some of what is known and believed to be generalizable about economic theory and instruments of pollution control. A second more general approach focuses on the related long-standing (at least since 1972) view that economic growth and increased consumption are the root causes of pollution problems, and therefore, reduced growth or even degrowth should be the heart of any solutions. A specific approach currently gaining in popularity is the incentive-based “payment for ecosystem services,” intended to counterbalance other profit motives by factoring in the economic value of functioning ecosystems but also critiqued as representing an inappropriate monetization of nature. Humans’ economic relationships with the environment are large multifaceted problems that demand a variety of approaches. Using theory and evidence to better understand the circumstances in which increases in human consumption are compatible with environmental protection is certainly one of the key issues of our day. Given what we already know about the nature of environmental assets and the potential for overusing waste assimilation services, better understanding economic incentives and appropriate instruments for pollution control are at least as important.

References Bluffstone R (2003) Environmental taxes in developing and transition economies. Public Financ Manag 3(1):143–175 Coase R (1960) The problem of social cost. J Law Econ 3:1–44. Reprinted in Oates W (1992) The economics of the environment. Edward Elgar, London

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Freeman AM (2003) The measurement of environmental and resource values. Resources for the Future, Washington, DC French H (1990) Green revolutions: environmental reconstruction in Easter Europe and the Soviet Union Worldwatch Paper No. 99. Worldwatch Institute, Washington, DC Krutilla J (1967) Conservation reconsidered. Am Econ Rev 57(4):777–786 Millennium Ecosystem Assessment (2005) Ecosystems and human well-being: synthesis. Island Press, Washington, DC Napolitano S, Schreifels J, Stevens G, Witt M, LaCount M, Forte R, Smith K (2007) The U.S. Acid Rain Program: key insights from the Design, Operation, and Assessment of a Cap-and-Trade Program. Electr J 20(7):47–58. http://www.epa.gov/airmarkets/resource/docs/US%20Acid% 20Rain%20Program_Elec%20Journal%20Aug%202007.pdf. Accessed 1 Jan 2012 Ostrom E (1990) Governing the commons: the evolution of institutions for collective action. Cambridge University Press, New York Pigou AC (1952) The economics of welfare, 4th edn. Macmillan, London Sachs J (1997) In: Bluffstone R, Larson BA (eds) Preface in controlling pollution in transition economies: theories and methods. Edward Elgar, London Sterner T (2003) Policy instruments for environmental and natural resource management. Resources for the Future, Washington, DC

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Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Governance Frameworks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Governance: A Relational Concept with Three Basic Styles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hierarchical Governance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Market Governance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Network Governance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Typical Problems of Environmental Governance Frameworks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Weaknesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Incompatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Cultural Dimension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Multi-Sector, Multi-Actor, and Multilevel Governance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Knowledge Base of Environmental Governance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Integrated Approaches to Global Environmental Governance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transition Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Environmental Metagovernance and Transgovernance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions and Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

This chapter introduces a broad view on global environmental governance frameworks, illustrated with some successful and failed attempts. As there are many definitions of governance, I first introduced an analytical model that captures all different strands of thinking. All governance definitions have their

L. Meuleman VU University Amsterdam, Amsterdam, The Netherlands Public Strategy for Sustainable Development, Brussels, Belgium e-mail: [email protected]; www.ps4sd.eu Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_59, # Springer Science+Business Media Dordrecht 2014

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merits and weaknesses and contribute to the overall set of frameworks for global environmental governance. Next, key issues like the multi-sector, multi-actor, multilevel, and cultural dimension are discussed. Keywords

Governance frameworks • Environmental governance • Metagovernance • Transgovernance

Definition Governance frameworks represent the totality of instruments, procedures, and processes designed to tackle a societal problem. They should be adapted to legal, cultural, and physical conditions of the problem environment and internally consistent; the normative assumptions (values, hypotheses) should be clear.

Governance Frameworks A governance framework can be defined as the totality of instruments, procedures, and processes designed to tackle a group of societal problems. Such frameworks are different for transport, energy, agriculture, and environmental issues, for example. They also differ in time and place, as they are expressions of policy theories in a certain time and location, and of value patterns typical for or politically en vogue in a certain nation or region or in an international organization like the World Bank or the United Nations Environmental Programme (UNEP). Combined with the fact that legal instruments can take many years of preparation to be in force, it should be no surprise that once a governance framework is established, it may be outdated or at least suboptimal. Therefore, modern governance theory emphasizes a long-term orientation, flexibility, robustness, and resilience of governance frameworks. Besides the fact that long-term thinking is typically scarce in politics as it may not deliver within a 4- or 5-year political cycle, these principles require a difficult trade-off with other principles such as reliability and stability. Governance frameworks, therefore, are constructed, and the challenge is not to find the one-and-only best approach, but a best fit: an approach which works best in a given situation, problem frame, and sociopolitical value context. Peer pressure between nations, however, has led to some convergence of national governance frameworks, because the idea of “best practices” which can be applied anywhere is popular. Such convergence is also happening on the global level. In the field of environmental governance, the relevance of transnational and international institutions is growing, and there are meanwhile more than 500 multilateral environmental agreements.

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Governance: A Relational Concept with Three Basic Styles The majority of governance definitions have several features in common. Governance is less about the content of policies (the what?) or about the vision behind policies (the why?), but concentrates on how to achieve objectives. Governance therefore is not about policy but includes polity (the institutions and instruments) and politics (the processes). In addition, governance is about the art of governing, and this includes the relations with those who are “governed,” regardless if they are considered as subordinates, partners, or clients. Therefore, it is a relational concept. Most governance definitions are value-laden. “Good governance” builds on the values of legitimacy, effectiveness, transparency, control, and efficiency. Many governance definitions (such as network governance, reflexive governance, adaptive governance) implicitly build on the view that actors value empathy, trust, and cooperation more than, for example, legitimacy, authority, or coercion. Further on, we will show that different styles of governance are linked to relational values, which define how people value other people’s values. A final common feature of the governance approaches we will discuss in this chapter is that their focus lies on public problems and opportunities. Environmental governance does not have to be confined to the public sphere, but this is the topic of this chapter. The following broad definition embraces these common characteristics. Governance is (after Meuleman 2008): The totality of interactions in which government, other public bodies, private sector and civil society participate (in one way or another), aimed at solving public challenges or creating public opportunities.

Three typical styles of environmental governance can be distinguished: hierarchical governance, market governance, and network governance. These styles are seldom found in a “pure” form but usually appear in combinations.

Hierarchical Governance Historically, the classical style of governance is hierarchy, defined by Max Weber. Hierarchical governance was the main approach of governments, at least since Napoleonic and Prussian times. Weber believed that governmental tasks could be split up in subtasks and that decision-making should be organized through top-down, rational processes based on legal instruments and without involvement of what we nowadays call “stakeholders.” Hierarchical governance has a range of characteristics which together compose a very strong logic (Table 98.1). Environmental governance emerged in the early 1970s, in a time in which governments were mainly organized by hierarchical principles, and the primary tools were laws

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Table 98.1 The logic of hierarchical governance (after Meuleman 2008) Governance dimension Culture/way of life Theoretical background Mode of calculation Primary virtues Motives Roles of government Strategy style Perception of actors Organizational orientation Aim of stocktaking actors Organization structure Flexibility Roles of knowledge Type of knowledge Coordination method Control through Communication style Leadership style Relation type Competences Values Aim of management development Problem type Type of instruments

Hierarchical governance Hierarchism Rational, positivism Homo hierarchicus Reliable Minimizing risk Government rules society Planning and design Subjects Top-down, formal, internal Anticipation of protest/obstruction Line organization, centralized Low Supporting authority Authoritative Imperatives Authority Giving information Top down Dependent Legal, financial Legitimacy, accountability, justice Increase obedience Crises, disasters, legal issues Laws, regulations, compliance

and regulations. This had a tremendous positive impact on environmental policy, because it enabled the establishment of a comprehensive legal framework based on standards, norms, and permits. Especially in urbanized areas, air pollution, fresh water contamination, wastewater and waste management, and noise were problems which were tackled with specific laws, first in industrialized countries. On the global level, legally binding agreements were developed. With the emergence of the “new modes of governance” we will discuss below, hierarchical governance instruments have become less fashionable. It is increasingly difficult to establish global legally binding agreements, as we have seen with climate change governance. The more decentralized approach also shows in the environmental policy of the European Union. The EU refrains from regulations which apply immediately and focuses on environmental directives which have to be transposed by the member states. This gives the EU countries the opportunity to adapt the directives to their particular situation.

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Market Governance In the 1980s, inspired by the popularity of neoliberal economics in Anglo-Saxon countries like the UK (Thatcher) or the USA (Reagan), a strong movement emerged in many Western nations which advocated running governmental organizations like businesses. The basic assumption was that private companies were more efficient and better organized and that governments should copy the management mechanisms used in companies and the competition within markets. Market governance is not the same as “leaving everything to the (economic) market,” as market actors also rely on “level playing fields” and other game rules produced by governments. Market governance has led to outsourcing and privatization of traditionally public tasks like energy production, health care, and the delivery of drinking water, but it is much more than that: It is a belief about how governments should work. Whereas hierarchical governance departs from a view of government “ruling” society, market governance considers governments as service providers for their “clients,” i.e., citizens and business. Market governance rapidly became popular in a range of countries and in international organizations like the World Bank and resulted in the establishment of many more or less independent government agencies, in result-oriented management (in fact, it introduced the term management as a novelty in public-sector organizations), and in cost-benefit analysis as a crucial method to measure success. In countries with a strong hierarchical culture like Germany or France, this style has never become as popular as in the UK and the Netherlands, for example. Market governance was sometimes merged with hierarchical principles in the so-called New Public Management movement: devolvement of tasks (market style) combined with sophisticated control and reporting mechanisms (hierarchical style). Like hierarchical governance, market governance comprises a large set of characteristics which together form a typical logic (see Table 98.2). The popularity of market governance made new tools for environmental governance available, such as the introduction of environmental taxes. A successful “early mover” was the Netherlands. Its Water Pollution Act introduced charges on the emission of wastewater, which led to a rapid decrease of such pollution in the Netherlands (Bressers and Lulofs 2010): The charges on water pollution came into existence as a side effect of the 1970 Surface Water Pollution Act that aimed at improving the strongly deteriorated quality of surface water. (. . .) So the law permitted water boards to introduce charges in order to cover their annual costs. The charges were meant as a mechanism to raise resources to finance. (. . .) Within a few years almost every water board had raised the rates to a level that it paid businesses, emitting their wastewater into the sewage system, to reduce pollution.

Another environmental policy instrument that follows the logic of market governance is the emission trading system (ETS). As with the Dutch water pollution taxes, this mechanism puts a price on pollution.

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Table 98.2 The logic of market governance (after Meuleman 2008) Governance dimension Culture/way of life Theoretical background Mode of calculation Primary virtues Motives Roles of government Strategy style Perception of actors Organizational orientation Aim of stocktaking actors Organization structure Flexibility Roles of knowledge Type of knowledge Coordination method Control through Communication style Leadership style Relation type Competences Values Aim of management development Problem type Type of instruments

Market governance Individualism Rational choice theory Homo economicus Cost-driven Maximizing advantage Government delivers services to society Getting competitive advantage Customers, clients Bottom-up, suspicious, external Finding profitable contract partners Decentralized, autonomous, agencies High Competitive advantage Cost-effective Competition Price Influencing, PR Empowering Independent Economy, marketing Self-determination, self-realization Efficient decision-making Routine problems, nonsensitive issues Service, contract, product

The popularity of market governance had a negative impact on environmental policy-making. In the 1990s and 2000s, it became more difficult to establish new environmental legislation. Market governance dislikes centralized regulation and prefers mechanisms that have a reputation for working well in corporate governance. Several scholars have argued that it is risky to leave out classical hierarchical principles in the governance mixture (Olsen 2006), especially with regard to environmental governance (Hey 2008).

Network Governance In the 1990s, public participation in the context of policy preparation emerged as a logical expression of the changing times. The emancipation of the general public, higher education levels, and the establishment of many large and small environmental advocacy groups put pressure on governments to listen better and in an earlier stage, to the interests of “stakeholders.” It was therefore logical that the

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Table 98.3 The logic of network governance (after Meuleman 2008) Governance dimension Culture/way of life Theoretical background Mode of calculation Primary virtues Motives Roles of government Strategy style Perception of actors Organizational orientation Aim of stocktaking actors Organization structure Flexibility Roles of knowledge Type of knowledge Coordination method Control through Communication style Leadership style Relation type Competences Values Aim of management development Problem type Type of instruments

Network governance Egalitarianism Social constructivism Homo politicus Flexible, discretion Satisfying identity Partner in a network society Learning style; chaos style Partners Informal, reciprocity, open-minded Better results and acceptance Soft structure, few rules and regulations Medium Shared good Agreed knowledge Diplomacy Trust Organizing dialogue Coaching, supporting Mutual dependent Social sciences, process management Community, empathy, harmony Learn to “muddling through” Complex, multi-actor, wicked problems Consensus, agreements, covenants

Environmental Impact Assessment Directive of the EU (1985) contained provisions for public involvement in an early stage of project permitting procedures. In 1998, the United Nations Economic Commission for Europe (UNECE) established the Aarhus Convention on public participation, access to environmental information, and access to justice, to which 45 European nations now have subscribed. A new style of governance emerged which is characterized by cooperation rather than coercion or competition, by trust rather than authority or price, and by interdependency rather than dependency or independency (see Table 98.3). Network governance is about dialogue and partnerships, which is very different from the top-down approach of hierarchical governance or the individualist attitude of market governance in which there are only buyers and sellers. Network governance has become popular among political scientists, even to the extent that some argue that hierarchy does not play an important role anymore. However, there is ample empirical research showing that hierarchy is “alive and kicking” and in many respects still the backbone of governmental action (Hill and Lynn 2005).

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Like the two other basic governance styles, network governance has brought new tools for environmental policy-makers. A good example is the introduction of covenants: voluntary agreements based on trust and partnership between governments and economic sectors such as the packaging industry. Network governance also embraced new negotiation methods, like the “Mutual Gains Approach,” in which actors with contradictory positions investigate together how they can help with each other’s interests, leading to so-called “win-win” package deals (Susskind and Field 1996).

Typical Problems of Environmental Governance Frameworks Networks, markets, and (hierarchical) bureaucracies are rivalling ways of allocating resources and coordinating policy and its implementation (Rhodes 2000, p. 345). Therefore, distinguishing hierarchical, market, and network governance and the tensions and trade-offs between them (Fig. 98.1) can help in understanding why (environmental) governance approaches sometimes just do not work. The governance triptych of Fig. 98.1 in combination with the characteristics of the three styles shown in Tables 98.1, 98.2, and 98.3 reveals three problems that have to be addressed: • All styles have their typical weaknesses and perversions. • The characteristics of the governance styles can be incompatible when combined. • The strong logic of the styles turns them into belief systems and panaceas.

Weaknesses The first problem concerns the weaknesses of each governance style. Hierarchical governance has several weaknesses, such as the tendency to create “red tape” (too much bureaucracy), not being able to deal with complexity and uncertainty (because the idea is based on a clear and fixed division of tasks), and creating opposition (because actors who have something important at stake are not listened to). The hierarchical style of communication has one direction, from sender to receiver, which is also not useful when the success of a policy depends on understanding and acceptance by affected groups. Climate change governance is an example of an environmental approach which is primarily hierarchical, which is argued to have been an important reason of the unsatisfactory results of the 2009 Copenhagen climate summit (Meuleman 2010). The focus on global, legally binding agreements and central organization is, however, in line with the most common framing of the problem: Climate change has been successfully defined as a global disaster which can only be solved with centralized measures and global norms (such as the 2 objective). An alternative would have been to frame climate change as a “wicked problem” (Rittel and

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Fig. 98.1 Tensions between the three environmental governance styles

Hierarchical governance

Network governance

Market governance

Webber 1973). Wicked problems are situations with a complex structure and where there is consensus neither on values nor on knowledge. A hierarchical vision of climate change brings about the risk that its governors become addicted to command, and see only emergencies instead of complexity (Grint 2010). Addiction to command and abuse of power are possible “perversions” of hierarchy: Power is addictive and there are examples of governors prolonging the existence of a crisis team because it has the advantage of quick and easy decisionmaking. Market governance, on the other hand, can produce many of the problems which are usually termed as “market failure.” The use of market mechanisms in public policies can lead to a loss of democratic control over independent agencies, to a priority on efficiency rather than on effectiveness, and to monopolies. The creation of “markets” for emissions trading has already resulted in the giving away of many emission permits for free by the same governments which established the system. The focus on financial issues may also lead to the perversion of corruption. Network governance also has its typical deficiencies. The dialogue on improving soil governance in the Netherlands in the late 1990s resulted in endless talks with no results, other than the shared conclusion of most parties that the Environment Ministry was their common enemy. Another common problem is the lack of clear lines of responsibility: In a multiparty process, everyone can blame the others if it fails. The key value of trust is also a risk: As a Dutch saying goes, “trust leaves by horse but arrives by foot.” The ultimate problem of network governance is that it is sensitive to manipulation.

Incompatibility The second problem regards the incompatibility of certain characteristics of the three main governance styles. A major reason why the conflict potential is high is that the three styles express different types of relations with other parties: dependency (hierarchy), interdependency (network), or independency/autonomy

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(market) (Kickert 2003, p. 127). A hierarchical “command and control” style of leadership will seldom lead to a consensus (network style) – even if this was the only feasible outcome of a policy process which the government was not able to “steer” with legal instruments. Decentralization or outsourcing (a typical market governance strategy) makes actors more autonomous. They become frustrated when detailed control mechanisms are introduced (hierarchical governance). The coexistence of “new modes of governance” with compulsory regulation, or hierarchy, is problematic. Sometimes attempts at a network approach are undermined by hierarchical governance inside one and the same public-sector organization. From the perspective of the classical hierarchical governance style, network governance is problematic because “governments, like the church, will find networks messy and carp at the mess” (Bevir et al. 2003, p. 206). Internal competition with the traditional hierarchical governance style is one of the reasons that the introduction of network governance sometimes fails. This competition can lead to obstruction from other public-sector organizations or other parts of the same organization and to unreliable behavior (not keeping promises, or sudden withdrawal of a negotiation mandate).

The Cultural Dimension The third problem is that each of the three basic governance styles – hierarchical, network, and market governance – has its own internal logic. If we define a culture as “the values, attitudes, beliefs, orientations, and underlying assumptions prevalent among people in a society” (Huntington 2000, p. xv) and consider cultures also as a dynamic pattern of assumptions in a given group (Schein 1987, p. 9), the three styles express cultures or “ways of life” (Thompson et al. 1990). They are looking glasses through which one can see only part of reality. The central value of hierarchical governance is authority; therefore authoritative and legitimate results are sought. The central values of network governance are empathy and trust, and therefore the results are preferably based on consensus. Market governance is based on competition and price, which makes it logical that the best results are the most competitive and cheapest products. This internal logic is so attractive that many public managers and politicians adopt one of the styles as their belief system or doctrine. To them, it presents a truth that has to be accepted without proof. Cases of environmental policy-making in the UK, the Netherlands, and Germany show that the governance style closest to the national culture was the first to be tried as the dominant style (Meuleman 2008). Only when this did not work were other styles considered and a situational mixture emerged. It is also fair to assume that different governance styles express how people consider other people’s values. Five relational values which express different relation types are (In’t Veld 2011):

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• Hegemony: “My values are superior to those of other people.” • Separatism: “I don’t want to be confronted with the implications of other people’s values.” • Pluralism: “Other people’s values may be valuable, and I am co-responsible for protecting them.” • Tolerance: “I find my values superior to other people’s values, but I abstain from interventions because of sympathy.” • Indifference: “I find my values superior to other people’s values, but I abstain from interventions because I am not interested.” To draw a broad typology, hegemony and separatism are related to the top-down and authoritarian thinking of hierarchical governance, pluralism, and tolerance to the empathy, trust, and respect of network governance, and indifference to the individualism and autonomy of market governance. Hegemonic thinking is congruent with top-down governance, and cultural pluralism seems to fit better to the character of many environmental challenges. If the complexity of an environmental problem leads to choosing network governance, pluralism or at least tolerance is a value to be expected. If hierarchical governance is chosen as the main style, its congruency with hegemony and separatism should be taken into account: It can destroy trust and innovation power. If a market-based approach is chosen, indifference towards values and traditions related to market governance can become a bottleneck for implementation. For “wicked” environmental problems, tolerance and pluralism should be expected to be productive approaches. The cultural dimension of environmental governance is not only relevant on the side of the “governors” but has also implications for which approach works where and why (or why not). Cultural pluralism is often seen as threatening environmental and sustainability governance; thus, the dominant attitude is, and has been, the need for assimilation of cultural and ethnical minorities, often euphemized as “integration” (Verweel and De Ruijter 2003). This policy of assimilation has created social tensions between different cultural groups in many countries. If we consider that environmental governance should be grounded in cultural values as drivers for social transformation, an alternative approach could be to not focus on communality – commonly shared values – but on compatibility (De Ruijter 1995). Communality is often politically framed as “integration,” as in Western immigrant policies, for example. In reality, this is a rather hegemonic assimilation. The compatibility principle recognizes that there are (in principle valuable) differences, which may cause tensions and incompatibilities, but that these differences should be regulated in one way or another. Developing a positive attitude towards cultural diversity in environmental governance and investing in compatibility of values and practices rather than on assimilation can lead to a rich variety of solutions to similar problems, instead of current governance practice in which centrally proposed solutions are often accepted in some cultures and rejected in others.

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Multi-Sector, Multi-Actor, and Multilevel Governance Environmental governance is multi-sector governance, as almost all economic sectors contribute to environmental pollution. After the initial set of legislation on the different environmental sectors (water, air, soil), the next step was to introduce environmental standards for economic sectors like the agriculture, transport, and industrial sectors. This “external integration” of environmental governance was supported by principles like the precautionary principle and the polluter pays principle. In the European Union, these principles and the principle that the environment should be integrated in all policies were formalized in the EU Treaty and in many sectoral EU policies. Environmental governance became part of all sectoral policies. This of course became disputed when in 2008 a financial-economic crisis emerged. Although this led to a lower priority for the environment in many EU member states, the European Commission maintained the conviction that environmental integration would lead to better economic and social outcomes in the long run. In 2011, for example, the Commission proposed that the post-2013 common agricultural policy should include a provision that 30 % of the income support for farmers would be used for environmentally friendly measures. The 2011 “Roadmap to a Resource Efficient Europe” includes a target to phase out environmentally harmful subsidies (including tax exemptions) by 2020. It depends on the regional or national context if environmental governance is also a multi-actor governance. In nations with a well-established civil society and with organized influence of the private sector and labor organizations on governmental policies, during the 1980s and 1990s a strong call emerged to include their interests in an early stage. This movement led to various initiatives. In some countries with a corporatist tradition, interactive policy-making emerged. On the UN level, the Aarhus Convention on public involvement and access to justice was a breakthrough. In the EU, after the Environmental Impact Assessment (EIA) Directive, in 2001 a Strategic Environmental Assessment (SEA) Directive for plans and programs was introduced. EIA and SEA have prevented much environmental degradation and have led to a better quality of decision-making. This is not only true in Europe but also in North America, where EIA was first established. Meanwhile, there are also developing countries which have procedures for EIA and/or SEA, for example, South Africa. The 1992 Rio Declaration gave another boost to including actors other than governmental authorities in decisions that could have an environmental impact by introducing national multi-stakeholder sustainable development councils. In the EU, such councils were established in most member states but with mixed success (Niestroy 2012). The success of such councils is dependent on, among other things, the existence of a civil society tradition, which was not the case, for example, in the former Eastern European accession countries. In nations with a well-established civil society and with organized influence of the private sector and labor organizations on governmental policies, during the 1980s and 1990s a strong call emerged to include their interests in an early stage.

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This movement led to various initiatives. In some countries with a corporatist tradition, interactive policy-making emerged. On the UN level, the Aarhus Convention on public involvement and access to justice was a breakthrough. In the EU, after the Environmental Impact Assessment (EIA) Directive, in 2001 a Strategic Environmental Assessment (SEA) Directive for plans and programs was introduced. EIA and SEA have prevented much environmental degradation and have led to a better quality of decision-making. This is not only true in Europe but also in North America, where EIA was first established. Meanwhile, there are also developing countries which have procedures for EIA and/or SEA, for example, South Africa. The 1992 Rio Declaration gave another boost to including actors other than governmental authorities in decisions that could have an environmental impact by introducing national multi-stakeholder sustainable development councils. In the EU, such councils were established in most member states but with mixed success (Niestroy 2012). The success of such councils is dependent on, among other things, the existence of a civil society tradition, which was not the case, for example, in the former eastern European accession countries. Since the 2001 White Paper on Governance, the EU has established as normal practice a broad public consultation for new policy processes. Such consultation takes place at the start of the internal Commission’s Impact Assessment procedure that looks at environmental, economic, and social impacts. Multi-actor environmental governance faces several challenges. One is the extent to which all interest groups are reached. To improve this, the EU supports civil society organizations with grants aimed at capacity-building, e.g., through the European Social Fund. Still, however, financially powerful actors, for example, the car industry, can exercise a strong lobby impact on policies. On the global level, the UN language is rich on inclusiveness. In Rio 1992, nine “major groups” were introduced, which have since been invited to discussions on global environmental and sustainability governance. An emerging issue is what role these groups should fulfil: Could it be more than advocacy and include also being part of the solution by entering partnerships with governmental and business actors? Another challenge is the question of capacity-building of civil society organizations in nations which do not have a tradition of this. Multilevel governance is a concept that addresses the need for linkages between different levels of decision-making. Usually the global, regional (supranational, e.g., European, Southern American), national, subnational, and local levels are distinguished, although the governance structure of nations differs widely: Sometimes there is no subnational governance, and in other cases the local level is weak. In some developing nations, the local level may have a formal and an informal side. In South Africa, for example, local governmental authorities and local tribal chiefs both have a say in decisions. Multilevel governance can be organized in a hierarchical way by transposing central agreements from the global down to the local level or in the form of multilevel partnerships (network governance). A market governance approach would be to decentralize decisions as much as possible, which is sometimes expressed in the formula “local when possible, central when needed.”

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According to Weiss and Thakur (2010), the UN has become the lead actor on global environmental governance and especially climate governance. There are more than 500 multilateral environmental agreements (MEAs) between nations registered with the UN, including 61 on atmosphere; 155 on biodiversity; 179 on chemicals, hazardous substances, and waste; 46 land conventions; and 197 on water issues (Kanie 2007). They form a crucial part of global environmental governance.

The Knowledge Base of Environmental Governance There are several comprehensive research projects on global environmental governance on which scholars from around the world collaborate. These projects address in an in-depth way issues similar to those we touch upon in this chapter. In addition to this growing body of knowledge on global environmental governance, the quality of the science base for such governance should be considered here. In 2000, the European Environmental Agency (EEA) published an important report on the environmental, social, and economic consequences of nonaction. The report “Late Lessons from Early Warnings” contains case studies on asbestos and other examples of failures to apply the precautionary principle. In 2012, a new volume with “Late Lessons” was published. One of the reasons for political nonaction even when scientific evidence is abundant is the tendency to focus on the short-term political election cycle. The roles of knowledge differ with the different governance styles. According to the hierarchical view, knowledge for policy-making should be authoritative. The broad political call for “evidence-based policy-making” seems to reflect this approach. However, who decides what “evidence is? We have seen that the authority of bodies like the Intergovernmental Panel on Climate Change (IPPC) is no longer taken for granted. Network governance assumes that valid knowledge is agreed knowledge; this explains a growing practice of forms of “joint fact finding”: stakeholder involvement in the knowledge base for environmental governance. It also stimulates open source knowledge and innovation, which has been made possible by the Internet and its communities. Market governance protagonists consider knowledge as a market good that should be cost-effective and may produce competitive advantage; the latter is a reason for intransparency. The view on the role of science in global environmental governance has been mainly hierarchical, but is moving towards a more inclusive one, which promises renewed trust in “scientific evidence.” In parallel, there is a trend towards more so-called transdisciplinary approaches, in which various disciplinary sciences (and sometimes practical or indigenous knowledge) are combined. In addition, there is a tendency to include a broader set of social science disciplines (e.g., behavioral sciences, anthropology, and sociology) as support for environmental governance, in addition to the natural sciences and economics. Ex ante assessment mechanisms and methods for measuring progress form an important dimension of the knowledge base of global environmental governance.

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In both domains, the involvement of the public and stakeholders is increasing. The EU strategic environmental impact assessments contain provisions for public involvement in an early stage. There are also proposals on the table for social cost-benefit analysis to include an interactive phase.

Integrated Approaches to Global Environmental Governance Transition Theory There are large environmental challenges that seem to require systemic change in addition to small steps. Climate change, water management, energy use and production, and food production are examples. The concept of “transition management” has emerged as an answer. This term suggests that such system changes can be “managed” and that the transition contains clear and predictable steps. However, it is widely accepted that this would be the exception and that the governance of transitions does not consist of one-size-fits-all approaches. Theory on environmental transitions has developed, and a promising approach (which is descriptive rather than prescriptive) is the niche-regime-landscape model. Innovations are considered to emerge on project level, in “niches.” If these innovations are successful, associated rules and other supporting mechanisms may constitute “regimes.” Gradually, a transition “landscape” will emerge in which niches and regimes are loosely linked (Grin et al. 2010).

Environmental Metagovernance and Transgovernance We have seen that hierarchical, network, and market styles of governance usually form combinations and that these combinations are not automatically successful. The success depends on the type of problem and on the culture and tradition of the region in which the environmental problems are tackled. The concept of metagovernance is defined to help design and manage governance combinations through combining, switching, and maintenance strategies and by including a thorough analysis of the governance environment (i.e., the influencing factors, including the views and powers of stakeholders and the general public) (Meuleman 2008). In the emerging concept of transgovernance, six social science concepts are combined in order to create a larger “toolbox” for sustainability governance (In’t Veld 2011; Meuleman 2012). For complex environmental challenges, this approach may also be helpful. The building blocks of this approach are: • Knowledge democracy (the move in politics, science, and media towards more interactive forms, while the old forms coexist) • Second modernity (the imperative that in our complex societies we should move from “or” to “and,” by increasing variation and by allowing redundancy) • Reflexivity (all social systems are in perpetual change and adapt to new circumstances)

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• Configuration theory (actors are usually “multiply included” in groups with a certain conviction, and innovation tends to not come from the center, but from those at boundaries of groups) • Transition theory (see above) • Governance theory (in particular metagovernance) Transgovernance could help overcome some of the typical misconceptions and often-repeated dead-end solutions, like the idea that only legally binding agreements can be successful or that cultures and traditions are a hindrance rather than part of the solution. In the discussion on whether the often-observed “fragmentation” of global environmental governance is a sign of duplication or complementarity (Ivanova and Roy 2007), transgovernance would probably favor the latter.

Conclusions and Outlook In this short chapter we have introduced the main characteristics and challenges of global environmental governance. We did not enter specific discussions on environmental problem-solving on biodiversity, land use, water, waste, and air, for instance, as our approach to governance is that governance frameworks should be tailor made not only to specific problems but also to specific situations. This situational approach to governance is also not specific for the global level alone, but applies to all levels, layers, and scales. There are several emerging themes that should be emphasized here; they were all addressed during the Rio + 20 UN conference on sustainable development in 2012. The first is the huge environmental challenges of megacities and other increasingly urban areas. This urban dimension might require a whole new field of governance approaches. Part of the solution might be the trend that local and subnational authorities engage in environmental governance on their own initiative and often in networks, regardless of global or national action is taken. This trend may be an expression of what is called “globalization”: Globalization makes people look for identification in their own (local) environment (“localization”) and stimulates interest in local food and other products while at the same time giving them access to knowledge about and communications with other such localities around the globe. Another trend with potentially large implications for global environmental governance is the increase of private-sector involvement. More than national governments or global agents, larger companies are observing that their resources (raw materials and energy) are becoming scarcer and more expensive and are moving towards long-term thinking. If they are open to partnerships with governments, science, and civil society organizations, new opportunities for global environmental governance may emerge. The third trend that could be game-changing is the increasing role of social media and social networks on the Internet. If social networks can be instrumental in regime change, as we have seen in Maghreb countries in 2011, there is no reason why they could not also be instrumental in environmental governance.

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References Bevir M, Rhodesand RAW, Weller P (2003) Comparative governance: prospects and lessons. Public Adm 91(1):191–210 Bressers H, Lulofs K (2010) Charges and other policy strategies in Dutch water quality management. CSTM Center for Clean Technology and Environmental Policy University of Twente, Enschede De Ruijter A (1995) Cultural pluralism and citizenship. Cult Dyn 7(2):215–231, Sage: London EU (1985) Directive on the assessment of the effects of certain public and private projects on the environment. Codified version 2011/g2/Eu,OJL 26,28.1.2012 Grin J, Rotmans J, Schot J (2010) Transitions to sustainable development. Routledge, New York Grint K (2010) The cuckoo clock syndrome: addicted to command, allergic to leadership. Eur Manag J 28(4):306–313, ISSN 0263–2373 Hey C (2008) Rediscovery of hierarchy: the new EU climate policies. Paper presented at the European University Institute, Florence, 20–21 June 2008 Hill CJ, Lynn LE Jr (2005) Is hierarchical governance in decline? Evidence from empirical research. J Public Adm Res Theory 2005 15(2):173–195 Huntington SP (2000) Cultures count. In: Harrison LE, Huntington SP (eds) Culture matters. How values shape human progress. Basic Books, New York, pp xvii–xxxiv In’t Veld RJ (2011) Transgovernance: the quest for governance of sustainable development. IASS, Potsdam Ivanova M, Roy J (2007) The architecture of global environmental governance: pros and cons of multiplicity. In: Swart L, Perry E (eds) Global environmental governance: perspectives on the current debate. Center for UN Reform Education, New York, pp 48–66 Kanie N (2007) Governance with multilateral environmental agreements: a healthy or ill-equipped fragmentation? In: Swart L, Perry E (eds) Global environmental governance: perspectives on the current debate. Center for UN Reform Education, New York, pp 67–86 Kickert WJM (2003) Beneath consensual corporatism: traditions of governance in the Netherlands. Public Adm 81(1):119–140 Meuleman L (2008) Public management and the metagovernance of hierarchies, networks and markets. The feasibility of designing and managing governance style combinations. Dissertation, Springer/PhysicaVerlag, Heidelberg Meuleman L (2010) Metagovernance of climate policies: moving towards more variation. Paper presented at the Unitar/Yale conference ‘Strengthening Institutions to Address Climate Change and Advance a Green Economy’, Yale University, New Haven, 17–19 Sept 2010 Meuleman L (2012) The cultural dimension of sustainability metagovernance. In: Meuleman L (ed) Transgovernance: advancing sustainability governance. Springer, Heidelberg Niestroy I (2012) Sustainable development councils at national and sub-national levels stimulating informed debate: stocktaking. Stakeholder Forum, sdg 2012 series. http://earthsummit2012. org/sdg2012/sdg2012-think-pieces#niestroy Olsen JP (2006) Maybe it is time to rediscover bureaucracy. J Public Adm Res Theory 16(1):1–24 Rhodes RAW (2000) The governance narrative: key findings and lessons from the ESRC’S Whitehall programme. Public Adm 78(2):245–263 Rittel HW, Webber MM (1973) Dilemmas in a general theory of planning. Policy Sci 4:155–169 Schein E (1987) Organizational culture and leadership. Jossey-Bass, San Francisco Susskind L, Field P (1996) Dealing with an angry public: the mutual gains approach to resolving disputes. Free Press, New York Thompson M, Ellis R, Wildavsky A (1990) Cultural theory. Westview, Boulder Verweel P, De Ruijter A (2003) Managing cultural diversity. J Today 2:1–20 Weiss T, Thakur R (2010) Global governance and the UN. An unfinished journey. Indiana University Press, Bloomington

Linguistic and Cultural Homogenization in the Face of Global Change, a Subarctic Example

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Contents Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Example: Language and Culture Loss Among Canada’s Subarctic Indigenous People . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Human cultures have always evolved in response to internal and external influences. There are numerous documented languages that have come and gone. However, languages and their associated cultures are being lost at an ever-increasing rate in recent generations. Of the estimated 6,000 languages currently spoken globally, it has been predicted that 50 % of these will be no longer used by the end of 2100 (UNESCO (2012) Atlas of the world’s languages in danger. UNESCO. http://www.unesco.org/culture/languages-atlas.Data. Accessed Mar 2012). Languages that have evolved in specific biomes often embody a wealth of knowledge and understanding of the local ecosystems and give rich expression to patterns of life that have been closely connected to these environments. Although the reasons for the demise of smaller localized cultures are complex, the forces of global economics and industrialization that often impose massive landscape-level environmental changes along with social, cultural, and linguistic expectations are one major influence. Subarctic cultures in Canada have experienced major cultural change due in part to extensive hydroelectric development throughout their homelands.

A. Luttermann Golden, BC, Canada e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_85, # Springer Science+Business Media Dordrecht 2014

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Keywords

Global language loss • Cultural change • Environmental change • Hydroelectric development

Definitions Language: In this section, “language” means the forms of human communication that may be spoken and/or written including vocabulary that is used according to certain structures and conventions. It also refers to nonverbal expressions of meaning that are an integral part of any unique language. Culture: The term “culture” is used here in its anthropological sense to refer to systems of shared ideas, beliefs, values, customs, behaviors, and manufactured environments that are common to the members of a particular people or society. These are passed on from one generation to the next and evolve through time.

Introduction Language in a basic sense is a system of communication among people, but it is also a fundamental expression of any groups’ cultural and historical identity. In most cases, unique languages that have evolved within specific geographic locations among people whose livelihood was tied to local ecosystems document a wealth of knowledge of the natural history of that region. They often possess extensive vocabulary that identifies and describes elements of the natural world as well as ecosystem relationships over time (Davis 2009). Languages also convey a diversity of ways of conceptualizing the world around us. Language loss is thus an indicator and a driver of cultural loss. The rate of global cultural change has increased exponentially over the past two centuries, with imperialism, mass migration, military conquest, and technology development all leading to the cultural domination of most localized societies. These cultures and their forms of expression are increasingly challenged by influences that are sometimes imposed, sometimes sought out, and sometimes embraced willingly. The mechanisms and intentions are myriad and complex; however, the reality is that the diversity of human cultures that have evolved over millennia, and the languages that define them, is dissolving into a larger homogeneity at an everincreasing rate. Of the world’s estimated 5,000–7,000 languages currently spoken, it is predicted that as many of 50 % of these will be extinct by the year 2100 (Hage`ge 2000). A project of the United Nations Educational, Scientific and Cultural Organization is charting the status of languages around the world (UNESCO 2012). The measures

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Fig. 99.1 Estimates of the relative vitality of the world’s languages (UNESCO 2012)

905 231 577

extinct since 1950 526

critically endangered severely endangered

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definitely endangered vulnerable

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of vitality assigned are based on several factors that relate not only to the absolute number of speakers at present but also to how the language is being used, passed on to the next generation, and supported by the surrounding society (Fig. 99.1). Reasons for the wide range in estimated number of languages currently spoken include the fact that many languages do not have a written form, but rather are passed on orally. There remains a lack of ethnographic and linguistic research to accurately identify the richness and diversity of the world’s languages. The value of maintaining human cultural diversity is a subject of debate (Harrison 2007). To some, language loss is a considered process of “natural selection” and survival of the fittest in the face of modernization. The contention is that if we all spoke the same language and lived in similar ways, we would get along better and have fewer misunderstandings. It is also argued that a common language can give us a greater ability to communicate about destructive forces and rally together to challenge and temper the more negative drivers of global change. To others, this loss of cultural and linguistic diversity is akin to loss of biological diversity and threatens the long-term fitness of our species and the health of our planet’s ecosystems. The cultural hegemony that Peoples around the world are currently subject to can include a loss of connection with and knowledge of local ecosystems, leading to a further loss of value and concern when these places are affected by landscape-level habitat conversions, contamination, and loss of biodiversity.

Example: Language and Culture Loss Among Canada’s Subarctic Indigenous People Stories of how smaller, more isolated cultures have been influenced by global change are unique to each region but share some similarities. In many cases, environmental change has been induced by large-scale industrial developments that are constructed, operated, and controlled by people from other places. Throughout Canada’s subarctic regions, these industries have brought their own cultural practices, norms, and expectations.

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“What is methylmercury?” An Innu-aimun translator and community consultation researcher asks me. “How can we explain that to the elders in Innu-aimun?” We are working on putting together some information about the environmental effects of large-scale hydroelectric development in the Innu traditional homeland of Nitassinan. This is a boreal and subarctic region that is now divided into the Canadian provinces of Newfoundland and Labrador and Que´bec. We come up with a description of what this compound is and why its levels increase in water and wildlife when large areas of boreal forest vegetation and soils are flooded by artificial reservoirs created for hydroelectric development. Bacteria in aquatic systems methylate the inorganic mercury naturally present in the ecosystem, changing it into a form that can be incorporated into biological tissue. Methylmercury is a neurotoxin in relatively small quantities. It bioaccumulates up the food chain and makes it potentially hazardous for humans to consume too many large fish of certain species from those bodies of water for several decades following flooding. Most of us anywhere have little understanding of this chemical process and its potential effects, whatever language we speak. We work on translating this information for the Innu elders, because they are being forced by government and industry to consider the relative costs and benefits of massive hydroelectric projects in their homeland. But the young people will just try to understand it in English. It is easier for them. They mostly learn how to read only in English. Innu-aimun was not a written language throughout most of its evolution as the language of the people of the eastern Canadian subarctic (Burnaby 2004). Many speak Innu-aimun at home with their parents and grandparents, but it is not the dominant language in the broader society around them. It is considered to be a “vulnerable” language according to the UNESCO language vitality index which means that most children currently speak the language but mainly at home. Innu-aimun has detailed descriptive language for rivers, countless features of the landscape, and the seasonal changes in water flow, plants, and animals found in the water and on the shores. Extensive areas of the Innu homeland have already been flooded or bulldozed, and rivers have been diverted. Major and minor landmarks have been altered or destroyed. As the land changes, so does the culture and the language. There will be new jobs and economic development, but the language of the workplace in this region is English or French. So, too, is the language of the bank, the post office, the grocery store, television and computers, and virtually every other part of the culture and society introduced over the years by the missionaries, traders, settlers, national and regional governments, and developers. The hunting and travelling patterns of Innu began to change to some extent back in the early 1700s in response to the fur trade. Since then, the abundance of wildlife has also been influenced by the number of European settlers moving into the region. In the 1950s and 1960s, the Innu seminomadic hunting, gathering, and trapping lifestyle began a dramatic shift with the introduction of government programs such

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as compulsory schooling, roads, telephones, electricity, travel by air, and government-provided health care (Mailhot 1997). A gradual shift to wage labor opportunities came along with all of these new elements of life. However, not until the advent of large industrial developments, such as the mines and hydroelectric facilities, has the land been so altered by human activities. Innu can still hunt and fish if they choose to, but the locations where one can find abundant, healthy wildlife with not too much human competition, are becoming more and more limited. The issue of contamination of fish with methylmercury leads to a loss of confidence in the safety and purity of the environment; a loss of comfort in eating wild or country foods. The “safe” and convenient comfort foods become processed products from the grocery store. The knowledge of how to hunt, fish, and travel on the land is effectively being lost along with family traditions of the hunting camp. Other forms of contamination such as oil spills from military training operations are also of concern. For many Innu, their unique culture and language are inextricably tied to the natural landscape within which it developed over thousands of years. It is not thought possible by Innu to understand this environment or Innu culture by reading about it in books. You have to live off the land to know it. But now the land is changing in major ways and people can no longer live in the old way. It is not even possible for the older people to recognize the rivers and lakes that were once there before the dams, roads, transmission lines, mines, and company towns were built in the 1960s and 1970s. Now more dams, mines, and roads are planned, etc., maybe even aluminum smelters. There is no end to the changes. This scenario has been repeated in numerous regions across Canada’s boreal and subarctic where massive hydroelectric projects have been built over the past 40 years. The Pimicikamak of northern Manitoba express their experience of these huge landscape transforming developments: “In the past, we always had to deal with a natural variability in the flows of the rivers, but there were mostly predictable patterns. Now the rivers are regulated by the hydroelectric company. You feel like your whole land and culture is controlled. We don’t know what is going to happen next. And now with climate change, that could affect how the hydro company uses the water even more.” (Philip Beardy, Pimicikamak Okimawin, Cross Lake, Manitoba 2012)

In the view of many Pimicikamak, the hydroelectric systems affect their lives in ways that are deep and complete. Optimism for the future of their culture is severely affected by the changes to the land: “The water is spiritual. Everything is spiritual. Right now the spirits are regulated by man. The beaver, the muskrat, the fish. . . they don’t know when the water levels are going to go up and down. We get notices about it, but we don’t know when it is going to start.” “We don’t have our freedom anymore.” I don’t want any more dams. “I wish there were dams that could be built without affecting the environment. But that is not possible. I am concerned about my children and grandchildren.”

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My late Dad told me, “Don’t spend your time on trapping, fishing and hunting – that will all be destroyed by the dams. The land, the resources, the wildlife will be destroyed. Go south and get an education instead.” He told me stories about how beautiful the land was, the water was clear, there were lots of beaver, moose and ducks. He told me about where he was born – how beautiful it was. I am glad I had the opportunity to travel and hunt on the land with my late Dad. Many times he would say, “I am lonesome”. “Why are you lonesome?” I would ask. “I am lonesome for my land – that was my livelihood. It will all be destroyed in the future”. He worked at the hydro project for some years when it was beginning, but they didn’t tell him what they were going to do in the end, why they were doing that work on the water.” “This is all a question of sovereignty and language.” (Jackson Osborne, Pimicikamak, Cross Lake Manitoba, 2012)

Of the 65 distinct indigenous languages and dialects spoken across Canada, only 3 – Cree, Inuktitut, and Ojibway – are considered to be viable over the long term. Nineteen are already nearly extinct as there are only a few elderly people left who speak these languages (Lewis 2009). In some cases, land rights agreements with aboriginal peoples in Canada are recognizing the environmental and cultural impacts of industrial projects and providing funding to revitalize cultural and linguistic traditions. This is despite the argument made by some industrial proponents that the language and culture would have been threatened by exposure to global culture anyway through media such as television and the Internet, regardless of local development and environmental changes. There are efforts to preserve indigenous culture and language. For example, not long ago, aboriginal children across Canada were punished for speaking their mother tongue in the residential schools they were forced to attend in great numbers to prepare them for assimilation into the modern Canadian culture (Miller 1996). Now, schools and hospitals are trying to encourage the use of Innu-aimun. For the new hydroelectric projects and mines proposed, there are promises to design working schedules and cafeteria food to appeal more to Innu cultural norms. Nevertheless, the better part of the economic and social structure of the new developments is patterned on the global industrial model. That quickly becomes the dominant culture, and here – as elsewhere around the world – unique cultures and languages are losing ground.

References Davis W (2009) The Wayfinders: why ancient wisdom matters in the modern world. Anansi Press, Toronto Harrison KD (2007) When languages die: the extinction of the world’s languages and the erosion of human knowledge. Oxford University Press, Oxford Lewis MP (2009) Ethnologue: languages of the world, 6th edn. SIL International, Dallas. http:// www.ethnologue.com/. Accessed Mar 2012 Mailhot J (1997) In the Land of the Innu: The People of Sheshatshit. Translated by A. Harvey. ISER Books, St. John’s

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Miller JR (1996) Shingwauk’s vision: a history of native residential schools. University of Toronto Press, Toronto UNESCO (2012) Atlas of the world’s languages in danger. UNESCO. http://www.unesco.org/ culture/languages-atlas.Data. Accessed Mar 2012

Additional Recommended Reading Burnaby B (2004) Linguistic and cultural evolution in an unyielding environment. In: Nesbit WC, Cahill MF, Jeffery GH, Philpott DF (eds) Cultural diversity and education: interface issues. Memorial University of Newfoundland, St. John’s Curl D (2005–2009) Innu aimun, Innu language. Memorial University, St. John’s. http://www. innu-aimun.ca/ Enduring Voices – Documenting the Planet’s Endangered Languages http://travel.nationalgeographic.com/travel/enduring-voices/ Hage`ge C (2000) Halte a` la mort des langues. Odile Jacob, Paris Harrison KD (2010) The last speakers: the quest to save the world’s most endangered languages. National Geographic Books, Washington, DC Nettle D, Romaine S (2000) Vanishing voices: the extinction of the world’s languages. Oxford University Press, New York Smith R (2005) Global English: gift or curse? English Today 21:56–62 UNESCO Endangered Languages: United Nations Educational, Scientific and Cultural Organization http://www.unesco.org/new/en/culture/themes/endangered-languages/

Human Rights, Rights of the Earth, and Global Change

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Martin Wagner

Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Human Rights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Environmental Rights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Substantive Environmental Rights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Procedural Rights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Filling the Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transboundary Harms and Environmental Rights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The International Environmental Obligations of Nongovernmental (Corporate) Actors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . La Oroya, Peru . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Climate Change and the Inuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Large Hydroelectric Dams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

Humanity has become a threat to the environment that sustains us. Global climate change, ocean acidification, air and water pollution, and other forms of environmental harm threaten ecosystems and human communities all over the planet. Human rights can protect both humans and the environment on which we depend. Long-recognized rights like the rights to life, health, and culture, as well as newer rights like the rights to water and a healthy environment, defend humans who depend on a healthy environment. Indigenous and cultural rights protect those who depend on the environment for their spiritual, cultural, or physical survival. Rights to participate in decisionmaking, to access relevant information, and to judicial remedies serve to

M. Wagner International Program, Earthjustice, San Francisco, CA, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_60, # Springer Science+Business Media Dordrecht 2014

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safeguard other fundamental rights. Ultimately, the scope of our power to harm the environment requires us to recognize and protect the rights of future generations and of Mother Earth herself. Keywords

Human rights • Cultural rights • Environmental rights • Future generations

Introduction “Remember, you have been given absolute power to bind and to loose, but the greater the power, the more terrible its responsibility.” Dostoevsky, The Brothers Karamazov.

The Earth’s environment has always changed. But the relatively new power of human beings to change the Earth and its environment on a massive, even planetary, scale has led some scientists to propose that we have entered a new era in the geologic history that they have termed the Anthropocene. Global climate change is perhaps the most obvious of these changes, but there are others: the contamination of shared resources such as air and water, the loss of entire ecosystems and species due to human encroachment or toxic pollution, and the spread of environmentally risky practices around the world through the mechanisms of global commerce. In addition to causing these changes, however, humans are also among the victims. Rising seas force communities and, soon, entire nations from their homes. Air pollution causes cancer, asthma, and other diseases. Drought and water pollution make it impossible for some people to access fresh water for drinking or to grow crops to eat. These few examples – and indeed the entire contents of this publication – make clear that global environmental changes affect human beings. But these effects are not evenly distributed. Around the world, indigenous peoples, the poor, women, and children are hit the hardest by environmental damage, while those who control and benefit from human-driven environmental change can shelter themselves from its worst effects. Polluting industries and toxic dumps are often located in the poorest nations and communities, where protective laws are weak or unenforced. The wealthy can move away from degraded environments, shelter themselves from heat and storms, or buy healthy food, clean water, and health services.

Human Rights Human rights are one of the most important tools available to those otherwise powerless to protect themselves from harm caused by other human beings. International human rights are humanity’s attempt to codify and guarantee the protections most essential to human life and well-being. In the words of the Universal

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Declaration of Human Rights, “recognition of the inherent dignity and of the equal and inalienable rights of all members of the human family is the foundation of freedom, justice and peace in the world”1. Human rights transform ethical and moral values into legal obligations that can guide the actions of governments and other powerful actors. Human rights law imposes on nations the obligation to “respect and ensure” the rights guaranteed in the human rights treaties and to take the steps necessary to give effect to the rights recognized2. In particular, this means that governments must: • Refrain from interfering with people’s enjoyment of human rights. • Prevent human rights violations by third parties.3 • Provide an effective remedy in the event that guaranteed rights are violated.4 • Cooperate internationally to achieve full enjoyment of human rights.5 In addition to imposing obligations on governments, human rights give individuals and communities authority and a voice they would not otherwise have. Before the advent of modern human rights and the associated institutions, individuals had no place in international law, which applied only to states and could only be enforced by them. If domestic laws and processes did not protect individual interests (and they frequently do not), individuals had no standing to hold their governments accountable under international law. Human rights changed that, creating rights and institutions that allow individuals to stand on equal footing with governments and to call them to account when they fail to guarantee fundamental rights.6 Human rights and the institutions that enforce them also provide a venue and voice for those injured by serious environmental harm. Because rights have a moral weight and emotional resonance other claims lack, putting an issue into the

1

Universal Declaration of Human Rights, Preamble, available at http://www.un.org/en/documents/ udhr/index.shtml. 2 See, e.g., International Covenant on Civil and Political Rights (ICCPR), Art. 2; International Covenant on Economic, Social and Cultural Rights (ICESCR), Art. 2. 3 See, e.g., Human Rights Council, General Comment 31, “Nature of the General Legal Obligation on States Parties to the Covenant,” } 8, U.N. Doc. CCPR/C/21/Rev.1/Add.13 (2004) (Under the ICCPR, “the positive obligations on states parties to ensure Covenant rights will only be fully discharged if individuals are protected by the state, not just against violations of Covenant rights by its agents, but also against acts committed by private persons or entities.”). 4 See ICCPR, supra note ii, Art. 2(3); Theo van Boven, “The Administration of Justice and the Human Rights of Detainees: Revised Set of Basic Principles and Guidelines on the Right to Reparation for Victims of Gross Violations of Human Rights and Humanitarian Law,” } 4, E/CN.4/Sub.2/1996/17 (May 24, 1996). 5 See, e.g., ICESCR, supra note ii, Art. 2(1) (All State parties undertake to “take steps, individually and through international assistance and cooperation, especially economic and technical” to realize the rights guaranteed by the Covenant.”). 6 See Louis B. Sohn, The New International Law: Protection of the Rights of Individuals Rather than States, 32 Amer. U.L., Rev. 1, 12–13 (1982) (footnotes omitted).

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context of human rights gives victims and their advocates a rhetorical tool they otherwise would not have and can help draw global attention to their plight.

Environmental Rights Human rights play two crucial roles with respect to environmental harm. Under the most traditional view of human rights, they are an important protection for those who are or may be harmed by environmental damage. There is growing understanding, however, that protecting human rights is a legitimate and valuable way to protect the environment itself. Until we recognize that the environment itself is entitled to rights, the rights of those who depend on the environment are an important proxy for the rights of the Earth and its ecosystems. For example, protecting the rights of indigenous and other communities who depend on forests for their cultural and physical survival requires ensuring the vitality of forests. The effects on humans and the effects on the environment are thus equally important components of the concept of environmental rights. The first official recognition that environmental harm could affect human rights came in the late 1900s. In the 1972 Declaration of the UN Conference on the Human Environment (the Stockholm Declaration), 114 nations acknowledged officially for the first time that the environment is “essential to [mankind’s] wellbeing and to the enjoyment of basic human rights – even the right to life itself.” Basic environmental health is necessary to the enjoyment of human rights, including the right to life.7 In 1982, the UN’s World Charter for Nature proclaimed, “Mankind is a part of nature and life depends on the uninterrupted functioning of natural systems which ensure the supply of energy and nutrients.”8 In the 1992, Rio Declaration on Environment and Development recognized that “[h]uman beings. . . are entitled to a healthy and productive life in harmony with nature” and recognized the importance of controlling “any activities and substances that cause severe environmental degradation.”9 Although these were important statements of general principle, they were of little practical value because they did not define what interests are protected or what actions give rise to concern. A clearer definition of environmental rights began to take shape as courts, international institutions, scholars, and activists applied the concept of human rights to real-world situations of environmental harm. These rights can be roughly divided into two categories: substantive environmental rights and procedural environmental rights.

7

Stockholm Declaration of the United Nations Conference on the Human Environment, Principle 1, G.A. Res. 2997, U.N. GAOR, 27th Sess., U.N. Doc. A/Conf.48/14/Rev/1, 11 I.L.M. 1416 (1972). 8 World Charter for Nature, Preamble, G.A. Res. 37/7, 28 Oct. 1982. 9 Rio Declaration on Environment and Development, U.N. ESCOR, Principles 1, 14, U.N. Doc. A/CONF.151/26 (Vol. I) (1992).

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Substantive Environmental Rights Environmental Implications for Existing Rights In 1994, after several years of fact-gathering, and in consultation with 17 other internationally renowned jurists, a United Nations human rights expert issued a report finding that environmental damage affects numerous specific rights, including the rights to life, health, food, safe and healthy working conditions, housing, self-determination and sovereignty over natural resources, information, popular participation, freedom of association, and cultural rights.10 In 1997, the Inter-American Commission on Human Rights examined the environmental effects of petroleum exploitation in fragile Amazon rainforests upon which indigenous peoples depended for their health and subsistence. The Commission recognized that “[s]evere environmental pollution may pose a threat to human life and health, and in the appropriate case give rise to an obligation on the part of a state to take reasonable measures to prevent such risk, or the necessary measures to respond when persons have suffered injury.”11 As courts and scholars have applied human rights to more and more specific instances of environmental harm, the list of human rights that may be undermined by environmental harm has grown. For example, air and water pollution that poisons people with toxic substances may violate their rights to personal integrity, life, and health. Dams that force people out of their homes may violate their right to property. The destruction of traditional lands may violate indigenous peoples’ rights to culture and means of subsistence. The rights at issue in any case of environmental harm will depend on the specific circumstances of the case. The Right to a Healthy Environment Defining environmental rights solely on the basis of other rights (like the right to life or health) has some significant shortcomings. For example, environmental protection may at times compete with the enjoyment of certain individual rights, such as the right to property. An approach that relies exclusively on existing rights that have not historically included any explicitly environmental rights could result in the sacrifice of environmental interests in the case of a conflict. One solution to this problem has been the recognition of a separate environmental right: the human right to a healthy environment. As an independent right, the right to a healthy environment has equal status to other rights and cannot be subordinated to other rights in the case of conflict. It must instead be balanced against other competing rights in a more nuanced manner. For example, restrictions on the use of property may be appropriate when the right to a healthy environment is at issue. 10

Review of Further Developments in Fields with which the [UN] Sub-Commission [on Prevention of Discrimination and Protection of Minorities] has Been Concerned: Human Rights and the Environment, Final Report Prepared by Mrs. Fatma Zohra Ksentini, Special Rapporteur, UN Doc E/CNB.4/Sub.2/1994/9, paras. 161–234. 11 Report on the Situation of Human Rights in Ecuador, OEA/Ser.L/V/II.96, Doc. 10 rev. 1, 24 Apr. 1997, Ch. VIII.

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The right to a healthy environment was first formally recognized in the 1972 Stockholm Convention.12 In her 1994 report based on an examination of “some 350 multilateral treaties, 1,000 bilateral treaties and a multitude of instruments of intergovernmental organizations,” the UN Special Rapporteur on Human Rights and the Environment concluded that under customary international law, “[a]ll persons have the right to a secure, healthy and ecologically sound environment.”13 Since then, a growing number of national constitutions and global and regional international agreements include a right to a healthy environment. As of 2012, 177 of the world’s 193 UN member nations recognize [a right to a healthy environment] through their constitution, environmental legislation, court decisions, or ratification of an international agreement. The only remaining holdouts are the United States, Canada, Japan, Australia, New Zealand, China, Oman, Afghanistan, Kuwait, Brunei Darussalam, Lebanon, Laos, Myanmar, North Korea, Malaysia, and Cambodia. Even among these laggards, some subnational governments recognize the right to a healthy environment, including six American states, five Canadian provinces or territories, and a growing number of cities . . . . Regional human rights agreements recognizing the right to a healthy environment have been ratified by more than 130 nations spanning Europe, Asia, the Americas, the Caribbean, Africa, and the Middle East.14

The Rights of Mother Earth The human rights approach to global environmental change is, by definition, human-centered. Whether the emphasis is on human rights that depend on a healthy environment for their fulfillment (such as the rights to life, health, or a means of subsistence) or on a separate right to a healthy environment, the emphasis is on what humans need, individually or collectively. It is on humans’ rights to a certain kind of environment.

12

Stockholm Declaration on the Human Environment, supra note vii, Principle 1 (Humankind “has the fundamental right to freedom, equality and adequate conditions of life, in an environment of a quality that permits a life of dignity and well-being, and he bears a solemn responsibility to protect and improve the environment for present and future generations.”). 13 Human Rights and the Environment: Final Report by Mrs. Fatma Zohra Ksentini, Special Rapporteur at 8, 79–80, Annex I, princ. 2, U.N. ESCOR, Hum. Rts. Comm., U.N. Doc. E/CN.4/ Sub.2/1994/9 (1994). 14 David Boyd, The Constitutional Right to a Healthy Environment, Env’t: Science and Pol’y for Sust. Dev’t, July-Aug. 2012, available at http://www.environmentmagazine.org/Archives/Back% 20Issues/2012/July-August%202012/constitutional-rights-full.html. Regional agreements also recognizing the right to a healthy environment include the Banjul [African] Charter on Human and Peoples’ Rights. Banjul Charter on Human and Peoples’ Rights, June 26, 1981, art. 24, 21 I.L.M. 58, 63 (1982) (“All peoples shall have the right to a generally satisfactory environment favorable to their development.”) (50 nations have signed); and the Additional Protocol to the American Convention on Human Rights in the Area of Economic Social and Cultural Rights (the Protocol of San Salvador), opened for signature Nov. 14, 1988, Art. 11, O.A.S.T.S. No. 69, 28 I.L.M. 156 (1989) (“Everyone shall have the right to live in a healthy environment.”).

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For those who recognize the inherent value of the environment independent of its relationship to humans, this human-centered approach is overly narrow and inadequate to the task of protecting the environment. When the human impacts of environmental harm are minimal, unrecognized, or unacknowledged, humancentered approaches are useless. This is particularly true in systems like the United States where environmentally harmful conduct may only be challenged in court by individuals with an economic or personal interest threatened by the environmental harm in question.15 A different approach, centered on the environment itself, proposes rights of the environment. Forty years ago, Professor Christopher Stone suggested that trees and other natural objects should have their own right to challenge another’s conduct in court.16 Although this concept has not taken hold in the United States, in many nations with constitutional provisions protecting the right to a healthy environment, “administrative processes and courthouse doors are now open to citizens who lack a traditional economic or personal interest but seek to protect society’s collective interest in a healthy environment.”17 In 2008, Ecuador went one step further, becoming the first nation to grant constitutional rights directly to the environment itself. The 2008 Ecuadorean constitution proclaims: Nature or Pachamama,18 where life is reproduced and exists, has the right to exist, persist, maintain and regenerate its vital cycles, structure, functions and its processes in evolution. Every person, people, community or nationality, will be able to demand the recognitions of rights for nature before the public organisms.19

In 2010, Bolivia followed suit with a law entitled “The Rights of Mother Earth.” Bolivia’s law established that Mother Earth – defined as “the dynamic living system made up of the indivisible community of all life systems and living beings, which are interrelated, interdependent, and complementary, and that share a common destiny”20 – has rights to life, diversity of life, clean air and water, ecological balance, restoration when harmed by human activities, and to be free of toxic contamination.21 The law gives Mother Earth legal status and creates obligations 15

This principle was established in the case of Sierra Club v. Morton, 405 U.S. 727 (1972). In a dissent in Sierra Club v. Morton, Justice William O. Douglas proposed that natural resources should themselves have standing allowing suits to be brought on their behalf. Id. at 741 (Douglas, J., dissenting). 16 Stone, Christopher D., Should Trees Have Standing? Toward Legal Rights for Natural Objects, 45 S. Cal. L. Rev. 450 (1972). 17 David Boyd, The Constitutional Right to a Healthy Environment, supra note xiv. 18 “Pachamama” means “Mother Earth” in the language of the Quechua and Aymara peoples of the Andes. 19 Constitution of the Republic of Ecuador, Article 71 (English translation available at http://pdba. georgetown.edu/Constitutions/Ecuador/english08.html). 20 Ley Corta de Derechos de la Madre Tierra, Art. 3, http://www.ftierra.org/ft/index.php? option¼com_content&view¼article&id¼4288:rair&catid¼152:cc&Itemid¼210. 21 Id. Article 7.

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on the part of the government and the people of Bolivia to defend Mother Earth’s rights. With the support of Ecuador and a handful of other countries, Bolivia has proposed that the United Nations similarly recognize the rights of the planet.

Indigenous and Cultural Rights International human rights institutions have recognized that “for historical reasons and moral and humanitarian principles, protecting especially the indigenous populations is a sacred commitment of the States.”22 In its 1997 Report on the Human Rights Situation in Ecuador, the Inter-American Commission on Human Rights noted that, under international law, “special protections for indigenous peoples may be required for them to exercise their rights fully and equally with the rest of the population,” and “to ensure their physical and cultural survival.”23 These considerations are directly relevant to environmental harm because of the particular importance of the close cultural, spiritual, and physical relationship many indigenous peoples have with the environment. In the words of the UN Human Rights Committee, “[C]ulture manifests itself in many forms, including a particular way of life associated with the use of land resources, especially in the case of indigenous peoples. That right may include such traditional activities as fishing or hunting and the right to live in reserves protected by law.”24 The UN Declaration on the Rights of Indigenous Peoples implements this by requiring states to conserve and protect the environment of indigenous peoples’ territories and to prevent the storage or disposal of hazardous materials there without their free, prior, and informed consent.25 The International Covenant on Civil and Political Rights provides that “ethnic, religious or linguistic minorities . . . shall not be denied the right, in community with the other members of their group, to enjoy their own culture, to profess and practice their own religion, or to use their own language.”26 For indigenous and other 22

Inter-American Commission on Human Rights, Resolution on the Problem of Special Protection for Indigenous Populations, OEA/Ser.L/V/II.29, doc. 38, rev. (1972) quoted in Situation of the Human Rights of Indigenous Persons and Peoples in the Americas, Inter-Am. C.H.R., OEA/Ser.L/ V/II.108, Doc. 62 (2000) at 1, n.1, available at http://www.cidh.oas.org/indigenas/intro.htm. See also, International Labour Organization Convention 169 concerning Indigenous and Tribal Peoples in Independent Countries (1989), available at http://www.ilo.org/dyn/normlex/en/f? p¼1000:12100:0::NO::P12100_ILO_CODE:C169; UN Declaration on the Rights of Indigenous Peoples (UNDRIP), UN GA Res. 61/295 (2007), available at http://www.un.org/esa/socdev/unpfii/ documents/DRIPS_en.pdf. 23 OEA/Ser.L/V/II.96, Ch. 10. 24 General Comment 23, ICCPR Article 27, U.N. Doc. HRI/GEN/1/Rev.1 at 38 (1994), para. 7. 25 UNDRIP, supra note xxii, Article 29. See also Convention Concerning Indigenous and Tribal Peoples in Independent Countries (ILO Convention No. 169), June 27, 1989, art. 15.1, available at http://www.ilo.org/dyn/normlex/en/f?p¼NORMLEXPUB:12100:0::NO:12100:P12100_ILO_CODE: C169 (“The rights of the peoples concerned to the natural resources pertaining to their lands shall be specially safeguarded.”). 26 ICCPR, supra note ii, Art. 27.

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peoples, group culture is often inseparable from the condition of their physical surroundings. For example, traditional subsistence practices like hunting are frequently central to cultural identity and to the transmission of cultural values to new generations. In such circumstances, widespread environmental harm may undermine the right to practice and enjoy the benefits of their culture.

The Rights of Future Generations Environmental rights must also acknowledge the rights of future generations. A healthy environment is as essential to the human rights of future generations as it is to the present one, yet future generations are powerless to prevent the present generation from overusing resources for its own benefit. In the context of the environment, the rights of future generations are recognized in the concept of sustainable development, which has been defined as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.”27 The 1972 United Nations Conference on the Human Environment concluded that “[humanity] bears a solemn responsibility to protect and improve the environment for present and future generations.” Many indigenous cultures recognize a “Seventh Generation” principle, whereby future generations have environmental rights that bind and guide the decisions of present generations.28 The 1998 Aarhus Convention recognizes that “every person has . . . the duty, both individually and in association with others, to protect and improve the environment for the benefit of present and future generations.”29

Procedural Rights Environmental rights, like environmental laws and regulations, are only effective if they are enforced. In the 1992 Rio Declaration on Environment and Development, over 150 nations recognized that “[e]nvironmental issues are best handled with the participation of all concerned citizens, at the relevant level.”30 Procedural rights are thus an important element of the protection and realization of environmental rights. Procedural environmental rights are generally considered to encompass three rights, to which those affected by potential environmental harm – or any concerned

27

“Report of the World Commission on Environment and Development,” General Assembly Resolution 42/187, 11 December 1987. 28 See N. Bruce Duthu, Native American Law, Climate Legacy Initiative Background Paper No. 3, http://www.vermontlaw.edu/Documents/CLI%20Policy%20Paper/BP_03%20-%20(Duthu).pdf. 29 Convention on Access to Information, Public Participation in Decision-Making and Access to Justice in Environmental Matters, Preamble, June 25, 1998, 38 I.L.M. 517 (1999), available at http://www.unece.org/env/pp/treatytext.html. 30 Rio Declaration, supra note ix, Principle 10.

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persons in a regime that recognizes an independent right of the environment – are entitled: • A right to information about activities that may harm the environment • A right to participate in decision-making about such activities, including an opportunity to be heard by the relevant decision-makers before potentially harmful activity occurs • A right to seek redress in courts or other institutions with power to remedy violations of environmental laws or rights, both before and after environmental damage occurs31

Filling the Gaps Two important questions at the developing edge of human rights scholarship and jurisprudence are of particular relevance to environmental rights. These are whether human rights and their corresponding obligations apply to environmental harm with a transboundary cause or effect and whether human rights obligations apply to nongovernmental actors, particularly corporations.

Transboundary Harms and Environmental Rights As John Muir wrote, “When we try to pick out anything by itself, we find it hitched to everything else in the Universe.” The environment does not stop at national borders. Ecosystems span national frontiers. Species migrate across borders. The climate system of the entire planet is affected by the health of the Amazon rainforests and the integrity of polar ice caps. Similarly, environmental harm does not recognize national boundaries. Air or water pollution in one nation can flow into another. Carbon dioxide emitted in one country contributes to global warming everywhere. Importantly, those causing environmental harm also travel freely across borders. All around the world, corporations are polluting or overusing natural resources in countries other than those in which they are incorporated, many of which are poor developing countries whose environmental commitments are overwhelmed by the economic power of large foreign corporations. The international nature of the environment and environmental harm calls for an international response. As described above, environmental rights are an important part of such a response. However, many international human 31

The strongest articulation of these rights is in the 1998 Aarhus Convention on Access to Information, Public Participation in Decision-making, and Access to Justice in Environmental Matters, but it has antecedents in human rights instruments such as the 1966 International Covenant on Civil and Political Rights, which guarantees every citizen the right and opportunity to “take part in the conduct of public affairs.” ICCPR, supra note ii, Article 25.

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rights agreements have been interpreted to limit governments’ human rights obligations to victims within their territory and subject to their jurisdiction. 32 Although this limitation almost certainly reflects an earlier time in which transboundary activities were less common, in today’s world of transnational corporations and growing understanding of the transboundary effects of actions such as the emission of greenhouse gases or the destruction of habitats essential to migratory species, “it would be unconscionable to so interpret [the ICCPR] as to permit a State party to perpetrate violations of the Covenant on the territory of another State, which violations it could not perpetrate on its own territory.”33 Although international institutions have recognized states’ obligation to refrain from action that violates human rights beyond their borders,34 the practical application of that obligation has been extremely limited and has seldom been applied to environmentally harmful activities. However, because international law requires all nations “to ensure that activities within their jurisdiction and control respect the environment of other States or of areas beyond national control,”35 it is logical and reasonable that the same requirement should apply with respect to environmentally harmful activities that affect human rights.

The International Environmental Obligations of Nongovernmental (Corporate) Actors Most environmental harms are not caused directly by governments, but are instead caused by nongovernmental corporate actors. Although international institutions have recognized the responsibility of incorporating governments to prevent

32

For example, the International Covenant on Civil and Political Rights requires governments “to respect and to ensure to all individuals within its territory and subject to its jurisdiction the rights recognized in the present Covenant.” ICCPR, supra note ii, Article 2.1. See also International Convention on the Elimination of All Forms of Racial Discrimination, 660 U.N.T.S. 195, Article 3; Convention Against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, 1465 U.N.T.S. 85, Article 2; Convention on the Rights of the Child 1577 U.N.T.S. 3, Article 2; International Convention on the Protection of the Rights of All Migrant Workers and Members of their Families, 2220 U.N.T.S. 3, Article 7; European Convention on Human Rights, Council of Europe Treaty Series, No. 5, Article 1; American Convention on Human Rights, 1144 U.N.T.S. 123, Article 1. 33 Saldias de Lopez v. Uruguay, UN GAOR, 36th Sess., Supp. No. 40, UN Doc. A/36/40 (1981), at 183. 34 See UN Office of the High Commissioner for Human Rights, 2009 Report CC-HR at 28, para. 86, available at http://daccess-dds-ny.un.org/doc/UNDOC/GEN/G09/103/44/PDF/G0910344.pdf? OpenElement. 35 Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, 1996 I.C.J. 226, 241–242.

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violations of some human rights by those corporations within their jurisdiction and control,36 such indirect responsibility is inadequate to prevent many corporate activities that threaten environmental rights. Because the power and influence of multinational corporations are often strong disincentives against regulation by the governments of the nations in which they operate, human rights obligations should apply directly to the corporations themselves. Although international human rights institutions have acknowledged that corporations should respect human rights,37 international law must evolve to recognize an independent, mandatory obligation on the part of corporate enterprises to respect human rights no matter where they operate.

Conclusion Human capacity to cause massive environmental damage – and thereby to threaten the well-being and survival of humans and other species – is undeniable. Our ability to cause irreversible harm calls on us to exercise our greatest wisdom to avoid such harm. Human rights are a profound expression of the collective wisdom of humanity. The happiness and survival of current and future human generations, as well as of the other species and ecosystems with which we share our planet, depends on respect for environmental rights in all aspects of individual and collective human activity. Box 1: Environment and Human Rights: Examples

La Oroya, Peru

For many years, a US-owned metal smelter located in the small Andean town of La Oroya, Peru, emitted almost ten times as much lead each year as emitted annually by all coal-fired power plants in the entire United States. Lead, mercury, and other toxins emitted into the air and water made their way into the bodies of residents of La Oroya, leaving 99.7 % of the children in the city with blood lead contamination levels requiring immediate medical treatment and

36

See 2009 Report CC-HR, supra note xxxiv at 28, para. 86. See also, e.g., Committee on Economic, Social and Cultural Rights, General Comment No. 14 (2000), The right to the highest attainable standard of health (article 12 of the International Covenant on Economic, Social and Cultural Rights), E/C.12/2000/4, 11 August 2000, Para 39 (“To comply with their international obligations in relation to article 12, States parties have to respect the enjoyment of the right to health in other countries, and to prevent third parties from violating the right in other countries, if they are able to influence these third parties by way of legal or political means, in accordance with the Charter of the United Nations and applicable international law.”). 37 See http://www.ohchr.org/documents/issues/business/A.HRC.17.31.pdf.

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almost certainly injuring their brains for life. These injuries violate the rights of the people of La Oroya to life, health, and physical integrity, among others.38

Climate Change and the Inuit Nowhere on Earth has global warming had a more severe impact than the Arctic. Rapid warming is devastating the culture and lives of the Arctic’s Inuit people. Sea ice has thinned and receded, causing hunters to fall through the ice and animals on which the Inuit depend for food to move farther from shore. Reduced sea ice makes ocean storms more severe and melted permafrost accelerates coastal erosion; these changes have forced some coastal villages to relocate. Loss of ice and flooding from rapid spring thaws makes travel more difficult and dangerous, while poor snow quality prevents travelers from using igloos to be safe during storms. Increased temperatures have heightened the risk of previously rare health problems in both the Inuit and in the animals on which they depend. Because the subsistence culture that is central to Inuit cultural identity depends on the cold, Arctic warming undermines the Inuit’s right to practice and enjoy the benefits of their culture, as well as numerous other rights such as the rights to life, health, property, physical security, and their own means of subsistence.39

Large Hydroelectric Dams In many parts of the world, the construction of large hydroelectric dams threatens human rights. In Panama, dams have flooded the homelands of indigenous peoples and others dependent on their ecosystem for survival, threatening their right to property and natural resources, physical security, and cultural integrity. Construction of dams or other infrastructure without the consent of indigenous peoples whose territory will be affected violates those peoples’ right to free, prior, informed consent.40 The persecution or killing of human rights or environmental defenders violates numerous rights, including the rights to life, and to freedom of expression and association.41

38

See http://www.aida-americas.org/en/project/laoroya_en. See Petition to the Inter-American Commission on Human Rights Seeking Relief from Violations Resulting from Global Warming Caused by Acts and Omissions of the United States, Dec. 7, 2005, available at http://earthjustice.org/news/press/2005/inuit-human-rights-petitionfiled-over-climate-change. 40 See, e.g., “UN Special Rapporteur Issues Report on Panama Dam,” 21 May 2009, available at http://www.culturalsurvival.org/news/panama/un-special-rapporteur-issues-report-panama-dam. 41 See, e.g., “Campaign Update– Panama: Another Nga¨be Protestor Killed,” 10 April 2013, available at http://www.culturalsurvival.org/news/campaign-update-panama-another-ngabeprotestor-killed. 39

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References David Boyd, The Constitutional Right to a Healthy Environment, supra note xiv Louis B. Sohn, The New International Law: Protection of the Rights of Individuals Rather than States, 32 Amer. U.L., Rev. 1, 12–13 (1982) Stone, Christopher D., Should Trees Have Standing? Toward Legal Rights for Natural Objects, 45 S. Cal. L. Rev. 450 (1972)

Environmental Ethics

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Joseph Mazor

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What Is the Permissible Level of Total Pollution of Global Common Environmental Resources? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . How to Fairly Allocate the Right to Pollute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

925 926 928 930 930

Keywords

Cost-benefit analysis • Deliberative democracy • Polluter pays • Climate change • Fairness

Definition Environmental ethics refers to that branch of philosophy that studies the moral relationship between human beings and nature. The moral concerns that global environmental change raises are both critically important and enormously complex (Gardiner 2011). Rather than trying to review all of the relevant ethical issues here,1 my goal in this short chapter will be to introduce the reader to the topic through two central questions. These questions are, first, how should we determine the right level of overall pollution of some common

1

For a fuller treatment of a variety of issues not treated here, see Gardiner et al. (2010), Light and Rolston (2003), and Schmidtz and Willott (2002). J. Mazor Department of Philosophy, London School of Economics and Political Science, London, UK e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_61, # Springer Science+Business Media Dordrecht 2014

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global natural resource and, second, what is the fair way to allocate the rights to pollute this resource? I will focus specifically on the issue of greenhouse gasses and climate change, though much of the analysis also applies to other global common environmental resources.

What Is the Permissible Level of Total Pollution of Global Common Environmental Resources? When addressing climate change, policymakers often talk as though the question of how much greenhouse gas should be permitted is a matter for science to work out. One goal often mentioned is 2  C warming over the next 100 years. Admittedly, science (including both natural science and social science) is indispensible for addressing this question. Science can give us a sense of the expected costs and benefits associated with the different options for various entities, both human and nonhuman. Science can also give us a sense of the relative uncertainty and riskiness associated with different possible options. Finally, it can predict certain thresholds or “tipping points” which, when crossed, trigger enormous costs. However, science cannot tell us how we should weigh the different costs and benefits that the different options generate for different entities. This is fundamentally a value judgment that lies in the realm of moral philosophy. Unfortunately, philosophers disagree about the right way of weighing the different considerations when deciding how much total pollution of common resources to allow. My goal here is to introduce two main approaches to addressing this issue and to highlight some of the difficulties with each. One approach is to use a cost-benefit analysis (CBA). On this view, determining the proper level of greenhouse gas emissions involves maximizing the net aggregate social benefits as measured in dollar terms. This solution is defended not only by some economists (Grafton et al. 2004, pp. 62–63) but also by certain prominent liberal thinkers (Nozick 1974, p. 79). However, this solution is quite problematic. First, it is inherently anthropocentric, taking into account environmental damage only insofar as it frustrates human preferences. Second, individuals’ willingness to pay (a key input into CBA) is heavily influenced by the current global distribution of wealth, which many scholars (e.g., Pogge 2002) have argued is unjust. Third, as it is carried out in practice, CBA often fails to sufficiently take into account the less obvious values of the environment to humans, including various cultural and ecological services. Finally, CBA is objectionable because it is concerned with aggregate economic advantage without sufficient attention to who benefits and who bears the costs. Now, in a single society where there are certain bonds between citizens, a common system of economic cooperation, and, most importantly, a system of wealth redistribution, the focus on setting pollution levels so as to maximize the “economic pie” might be justified. But in a global context where no common

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government exists, the fact that a certain pollution level maximizes aggregate economic benefits seems wholly inadequate to justify that particular level of pollution, given the very high costs (both monetary and nonmonetary) that particular individuals or certain nations will have to bear. A second approach to determining the total pollution burden is to rely on a legitimate democratic process that gives voice to all of the relevant stakeholders. Many political philosophers have rejected the idea that we can appeal to grand theories of justice to resolve our fundamental moral disagreements. Instead, they have argued that the best we can hope for is an outcome that is the result of a fair and legitimate decision-making procedure. Recently, a variety of theorists have argued that the right type of decision procedure entails inclusive and public-spirited deliberation (For a list of theorists who are sympathetic to this proceduralist view, see Gutmann and Thompson (2002, p. 153, fn. 1). Gutmann and Thompson reject this view, but end up supporting a partial deliberative democratic procedural approach). The most obvious problem with this approach is that it seems utopian. Many scholars have highlighted problems with this deliberative approach in the domestic context (e.g., Shapiro 1999). However, the problems with utilizing this approach to determine, say, the total level of permitted greenhouse gasses are even more severe (for a more detailed discussion of some of the problems in the context of deliberation about climate change in the UK, see Few et al. (2007)). The first problem is that, even when deliberations about global environmental issues do occur, it is not clear that there exists sufficient trust and good faith on the part of all the parties to satisfy the conditions of legitimate deliberation. Second, there are doubts as to whether the deliberating parties sufficiently represent their own citizens, let alone future generations and the interests of various nonhuman entities. Finally, the lack of enforcement mechanisms and the power imbalances among the different parties significantly undermine the effectiveness and legitimacy of this type of deliberation in the global arena. Proponents of this approach might argue that all these problems simply point to a need for global institutional reform. Yet this response may simply be too quixotic, even in the idealistic realm of philosophy. More importantly, even if the right type of global deliberative institutions were implemented, there remains the question of how a person in this deliberative democratic context should weigh the different considerations. Surely, she should not simply speak and vote based on self-interest. Nor is it satisfying to suggest that the person should simply use her intuition to balance the different considerations. Instead, it seems that the deliberative solution has simply shifted the problem of finding a just solution from the policymaker to the individual deliberator. Many political philosophers have instead argued that we need to think of the problem in terms of rights rather than in terms of deliberative procedures or in terms of adding up costs and benefits (for an example of a critique of CBA and tentative arguments for considering rights, see Kelman (1992)). Yet how exactly we can determine who has which rights when it comes to common resources, especially in

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a complex global context, is an enormously difficult question and a pressing topic for future research.

How to Fairly Allocate the Right to Pollute However we determine the total permissible level of pollution of common environmental resources; often this level will be significantly lower than the quantity that is currently projected to be released. Yet reducing pollution is quite often economically painful. This raises the moral question of who should have the right to pollute common resources. To make the issue even more concrete, we might imagine that we have agreed to use a cap-and-trade system for greenhouse gas emissions and have decided on the total cap.2 The question, then, is how the rights to emit this quantity of greenhouse gasses should be distributed. There are a variety of competing morally compelling yet controversial principles that seem to bear on this question. Some might argue that those who contributed most to the problem should have the primary responsibility to fix it (Singer 2010, pp. 187–190). After all, it is the developed nations that produced much of the greenhouse gasses currently in the atmosphere and that were able to benefit economically through this pollution. On this view, they are the ones who should bear the largest burden for reducing emissions. However, there are at least two objections to this proposal. First, some have argued that although the developed countries have produced the most pollution, many of the products of that pollution have been consumed by individuals in developing countries.3 Thus, the focus on who actually did the polluting is too simplistic. Second, and more importantly, it has been pointed out that early on, when at least some portion of the pollution was occurring, the polluters did not know the damage that they were causing.4 Given that the costs of addressing this damage are enormous, it may not be reasonable to hold the developed nations fully responsible for all of the emissions that they produced in the past. A second proposal that is much more favorable to developed nations is to use current emission levels as a baseline for determining how much each state should have to cut (this is often referred to as “grandfathering proposals”). Arguments for these proposals often focus on the importance of not disrupting expectations. Certain states have developed ways of life and economies that depend on being 2

It is worth noting that a variety of philosophers, e.g., Goodin (2010), have objected to the sale of the right to pollute. 3 For a discussion of this issues, see Singer (2010, p. 192). Note also that this argument can also be used by developing countries to argue that the emissions that they are responsible for are quite overstated since many of their products end up in the developed world. 4 It is an interesting question of when polluting countries knew or should have known that greenhouse gasses might have potentially disastrous consequences. For a discussion of some of the relevant history, see Chap. 6 of Oreskes and Conway (2010).

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able to emit large amounts of greenhouse gasses. If we do not take existing emission levels into account, the reduction targets would be enormously disruptive to these economies. Thus, there is a rationale for using current emission levels as a baseline for determining the proper distribution of the painful cuts in greenhouse gasses. There are, however, several problems with this proposal. First, expectations are only worthy of respect if they are legitimate or reasonable. Since states have known or should have known that their rates of greenhouse gas emissions are unsustainable, the economic conditions and way of life that they have grown accustomed to given these emissions should not be given any moral weight. In fact, to give these expectations moral weight would be effectively to reward these states for being irresponsible. Second, this proposal ignores the real differences in the standards of living of different countries. It seems perverse to ask developed countries with a high standard of living to make relatively small sacrifices (by basing reduction targets on current pollution levels) while insisting that countries that are still very poor, and that, in some cases, need to produce emissions in order to lift their people out of poverty, should not be allowed to pollute. Third, this proposal is based on an overstatement of the problem for developed countries. After all, emission rights are tradable. Thus, if the governments of developed nations place a high value on not disrupting the relevant greenhouse-gas-emitting industries, then they are free to subsidize their industries’ purchase of the relevant pollution permits from less developed countries. An intermediate solution that is often proposed as a compromise between these two views is equal per capita emissions (Singer 2010, pp. 194–197). On this view, each country should receive pollution permits that are in the same proportion to the total permits as that country’s population is to the total global population. Intuitive considerations of fairness are often appealed to in order to ground this solution. However, this solution is also subject to several objections. First, this proposal seems to reward countries that have been or will be irresponsible with their population policy (Singer 2010, p. 191). It also penalizes nations whose population has been decimated through some injustice or natural calamity. Second, it is unclear why equality of resources (e.g., pollution permits) should be the standard rather than equality of some other kind across people. Third, it is not obvious why rights to pollute the atmosphere should be treated separately from other rights to natural resources such as oil and land. There is one additional overarching objection to all of these proposals. Every proposal I have considered assumes that we first decide on the total cap and then we use some separate moral principle to decide how the relevant emission rights should be divided. However, the two questions may not be so easily separable. For example, we might decide on the total level of greenhouse gasses by aiming for some type of equality of benefits between different parties. However, given that different levels of global warming will have drastically different consequences for different parties, we might want to allocate the permits to “even out” these consequences (e.g., by giving more permits to those who are most harmed

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by global warming). The more general point is that the distribution of permits may be an integral part of the decision on how much pollution to allow. On this view, treating it as a separate question is a mistake (albeit one that is common in the literature).

Conclusion Just as global environmental change has raised a variety of pressing questions for scientists, so too it has raised thorny new problems for philosophers. I have focused in this chapter on two of these problems: the first is determining the total level of pollution for some global common resource and the second is how the right to pollute should be distributed. Many other moral issues in environmental ethics that bear on global environmental change have not been considered here. These include questions regarding the intrinsic value of nature (Callicott 1984), the standing of future generations (Beckerman and Pasek 2001), and the role of scientific uncertainty in moral decision-making (Gardiner 2010, pp. 7–9). However, even without a full discussion of these issues, I hope to have shown that addressing global environmental change requires answering not only the empirical questions of environmental science but also the normative questions of environmental ethics.

References Beckerman W, Pasek J (2001) Justice, posterity, and the environment. Oxford University Press, Oxford Callicott JB (1984) Non-anthropocentric value theory and environmental ethics. Am Philos Q 21(4):299–309 Few R, Brown K, Tompkins E (2007) Public participation and climate change adaptation: avoiding the illusion of inclusion. Clim Policy 7(1):46–59 Gardiner S (2010) Ethics and global climate change. In: Gardiner S, Caney S, Jamieson D, Shue H (eds) Climate ethics: essential readings. Oxford University Press, Oxford Gardiner S (2011) A perfect moral storm: the ethical tragedy of climate change. Oxford University Press, Oxford Gardiner S, Caney S, Jamieson D, Shue H (eds) (2010) Climate ethics: essential readings. Oxford University Press, Oxford Goodin R (2010) Selling environmental indulgences. In: Gardiner S, Caney S, Jamieson D, Shue H (eds) Climate ethics: essential readings. Oxford University Press, Oxford Grafton R, Hill R, Adamowicz W, DuPont D, Renzetti S, Nelson H (2004) The economics of the environment and natural resources. Blackwell, Malden Gutmann A, Thompson D (2002) Deliberative democracy beyond process. J Polit Philos 10(2):153–174 Kelman S (1992) Cost-benefit analysis: an ethical critique. In: Gillroy J, Wade M (eds) The moral dimensions of public policy choice. University of Pittsburg Press, Pittsburgh Light A, Rolston H (eds) (2003) Environmental ethics. Blackwell, Malden Nozick R (1974) Anarchy, state, and utopia. Basic Books, New York Oreskes N, Conway E (2010) Merchants of doubt. Bloomsbury Press, New York Pogge T (2002) World poverty and human rights. Polity Press, Cambridge, UK

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Schmidtz D, Willott E (2002) Environmental ethics: what really matters, what really works. Oxford University Press, New York Shapiro I (1999) Enough of deliberation: politics is about interests and power. In: Macedo S (ed) Deliberative politics: essays on democracy and disagreement. Oxford University Press, New York Singer P (2010) One atmosphere. In: Gardiner S, Caney S, Jamieson D, Shue H (eds) Climate ethics: essential readings. Oxford University Press, Oxford

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Contents Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inequality Manifested by Environmental Disparities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inequality as Driver of Environmental Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inequality Blocks Solutions to Environmental Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Moving Towards Sustainability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Disparities of social status, wealth, income, and political power have been growing over the past several decades, both within and between nations. Socioeconomic inequality is now understood to be integrally linked to environmental degradation, climate change, and blocking of pathways to sustainability. I provide a brief overview of the evidence and arguments for this link, organized around three propositions: that environmental degradation is one of the main ways in which socioeconomic inequality is manifested, that socioeconomic inequality is one of the primary drivers of environmental degradation, and that issues of socioeconomic equity must be addressed before we can make progress on solutions to global environmental problems and transition towards sustainability. Keywords

Socioeconomic inequality • Equality • Equity • Sustainability

D.S. Rogers Institute for Research in the Social Sciences (IRiSS), Stanford University, Stanford, CA, USA e-mail: [email protected]; [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_62, # Springer Science+Business Media Dordrecht 2014

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Definitions Socioeconomic inequality refers to disparities in income, wealth, status, and political access, all of which tend to go together. Equality is a quantitative standard, determined by the level of similarity in these metrics. Equity, on the other hand, is a qualitative ethical concept that refers to the level of fairness in the outcomes for different individuals or groups. Social sustainability refers to the ability of societies to meet human physical, social, and emotional needs on an ongoing basis. Equality and equity are integral to social sustainability.

Introduction The causes and consequences of socioeconomic inequality are one of the most important and long-standing topics of investigation in the social sciences. Disparities of social status, wealth, income, and political power have been growing over the past several decades, both within and between nations (Wade 2001; Cornia et al. 2004; UN DESA 2005; Kenworthy and Pontusson 2005; World Bank 2011). Socioeconomic inequality is now understood to be integrally linked to environmental degradation, climate change, and blocking of pathways to sustainability. In this chapter I will provide a brief overview of the evidence and arguments for this link, organized around three propositions: 1. environmental degradation is one of the main ways in which socioeconomic inequality is manifested 2. socioeconomic inequality is one of the primary drivers of environmental degradation 3. issues of socioeconomic equity must be addressed before societies can make progress on solutions to global environmental problems and the transition towards sustainability.

Inequality Manifested by Environmental Disparities A major way in which socioeconomic inequalities are expressed is through environmental disparities – that is, differences in the quality of the community’s or neighborhood’s surrounding environment and the form and amount of environmental impacts on the local and global environment. This takes place in several ways: • Real estate in more desirable locations generally costs more. Thus poorer people generally live in locations with more pollution and fewer natural amenities such as good soil, ample clean water resources, and greater natural beauty. • Poorer communities are more likely to bear the brunt of environmental degradation due to polluting economic activities. This is the case both because of differentials in land prices (e.g., industry will choose to locate in

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areas where land prices are lower) and also because of outright bias in siting decisions by government decision-makers (who are less likely to antagonize well-to-do constituents by locating an objectionable facility in their vicinity). This is the classical “environmental justice” issue that has been the subject of some citizen activism over the past few decades (Cole and Foster 2000; Rechtschaffen and Gauna 2002; Haughton 1999). • Poor communities generally do not have the resources to adapt to environmental degradation and climate change. While rich communities can pay to access alternate natural resources, reengineer infrastructures, and invest in new subsistence and economic activities, poor communities do not have the same capability. Hence they suffer the consequences of environmental degradation more directly and severely. • Although poor communities experience worse environmental impacts, the poor generate significantly less impact on the environment as measured by standardized metrics such as consumption or carbon output. For example, a study in India documented that landless and smallholder peasants generated only one-quarter the carbon of well-to-do urbanites (Michael and Vakulabaranam 2012). In the Middle East, another study has shown that poor populations within Israeli territory (bottom income decile) generate only one-twenty-fourth the amount of carbon emissions from electricity and automobile use that the top income decile generates (Rabinowitz and Lubanov 2011). This difference has been obscured for years by the more obvious fact that poor communities, especially in the developing world, impact their local environment in very direct and visible ways such as deforestation caused by gathering of firewood and livestock grazing or pollution of surface waters by untreated sewage – both of which are caused (in part) by lack of resources to develop alternative approaches. It should be noted that the environmental disparities experienced by those on the lower rungs of the socioeconomic ladder have the effect of perpetuating and compounding their economic difficulties and lack of economic mobility. This can take place through substantial and debilitating health impacts, loss of soil fertility (and thus nutrition as well as income), the need to travel long distances to obtain suitable water resources, and so forth.

Inequality as Driver of Environmental Change Socioeconomic inequality is, in itself, a significant driver of both local and global environmental change in at least three ways. First, the existence of socioeconomic inequality (disparities in social status) drives excess consumption (Aydin 2010), leading to a greater burden through natural resource use and waste disposal. Wilkinson and Pickett put this best in their pivotal book on the impacts of inequality (Wilkinson and Pickett 2009): “A very important part of what fuels consumption. . .is status competition—keeping up with others, maintaining appearances, having the right clothes, car, housing, education, etc., to compare favorably with others. All these pressures are intensified

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by greater inequality.” Although this understanding dates back at least to the time of Thorstein Veblen’s writing on “conspicuous consumption” (Veblen 1899), scientists are only recently recognizing the connection with environmental degradation. Second, socioeconomic inequality is a major factor in large family size and thus population growth. The inequality of women – a form of disempowerment including lack of access to education, jobs, political voice, birth control, and other health services, as well as lack of empowerment in personal relationships – is one of the reasons behind repeated pregnancies, even when the woman would prefer not to have more children (Arshad 2012; Birdsall 1988). Moreover, without public provisions for the well-being of children and older family members, the poor depend upon large families to ensure that children survive to adulthood in order to feed and care for the elderly. The expectation of high rates of child mortality often motivates the choice to have more children, while the survival of the elderly may be dependent on subsidies generated by having enough healthy adults of working age in the family – again motivating larger family size (Nugent 1985). It goes without saying that high population density is one factor that contributes to environmental degradation, although it is certainly only a part of the equation – the other being the much higher levels of consumption by the rich (Ehrlich and Holdren 1971). Third, socioeconomic inequality, which goes hand in hand with political inequality, allows political, economic, and natural resource benefits to be diverted to elite families and business concerns (Korten 1995; Stiglitz 2003; Easterly 2002; Perkins 2004; Klein 2007; Acemoglu and Robinson 2012). Meanwhile the general public, including the poor, are often left holding huge sovereign debts or suffering the social, economic, and environmental consequences of the profitable but unsustainable development. This can take place with privately funded development but more likely happens with publicly funded projects such as those arranged by the IMF and World Bank. Making matters worse, inequality is linked to corruption (likely as both cause and effect), which creates a scenario for even further abuses of public funding to generate profitable but environmentally destructive development (You and Sanjeev 2005; Rogers 2012).

Inequality Blocks Solutions to Environmental Problems There are countless ways in which both local and global environmental degradation can be addressed and pathways to sustainability can be initiated. Unfortunately, socioeconomic inequality has the effect of blocking or thwarting many of these potential solutions in the following ways: • Socioeconomic inequality blocks sustainable development by diverting resources to the elites and profit-generating business instead, as mentioned in the section above. • Growing inequality means the poor get poorer, either in relative or absolute terms, even as the overall economy grows (Cornia et al. 2004; UN DESA 2005; World Bank 2011). This phenomenon is true over many regions of the

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developing world and also in the BRIC nations (Brazil, Russia, India, and China). This means there are many more people who do not have the resources to implement more sustainable subsistence and economic activities. Socioeconomic inequality increases the rate of societal ills, ranging from poorer physical and mental health through higher rates of teen pregnancies, drug use, high school dropouts, crime, homicides, and incarceration (Wilkinson and Pickett 2009). This takes place through many mechanisms including stress, prejudice, conflict, and lack of access to resources. Regardless of the causes, the results are clear: communities and societies are overwhelmed with social crises and cannot turn their attention to environmental degradation and sustainability. Socioeconomic inequality spurs migration, as people move elsewhere in the attempt to make a better living (Liebig and Sousa-Poza 2004; Stark 2006). This results in a population which is either not invested in a particular locality or perhaps lacks the knowledge or the political influence to push for needed changes in the society in which they currently live. Latino seasonal workers in the US agricultural sector, for example, are well aware of environmental abuses and health hazards associated with agrochemical use but often lack the specific knowledge and influence to report illegal chemical use or advocate for regulation. An exception to this trend was the successful campaign of the United Farm Workers in the 1960s–1970s (Shaw 2008). Socioeconomic inequality blocks local communities from protecting their environment against various forms of degradation (Boyce 2003; Eriksson and Persson 2003; Magnani 2000; Morello-Frosch et al. 2002). People without the necessary economic resources, knowledge, and political clout in their community are unable to demand changes that are necessary. Often, despite enormous and sophisticated grassroots or civil society efforts, the power differentials between the general community and the elites who stand to benefit from environmentally damaging economic activity are simply too great to overcome. One of the most disturbing but representative examples of this problem was the devastating pollution caused by the development of the oil extraction and refining industry in the Niger Delta region of Nigeria (Watts and Kashi 2008). When civil society efforts failed to bring the situation under control, an armed resistance formed, engaging in kidnappings and takeovers of oil platforms at sea. They were able to cause considerable trouble for the operations of the multinational oil companies involved in Nigeria but were ultimately unsuccessful when well-funded paramilitary militias were formed to overcome the local citizen resistance. Socioeconomic inequality often complicates the implementation of local sustainability mechanisms (Kosoy and Corbera 2010; Kosoy et al. 2008; Grieg-Gran et al. 2005; Steed 2007). Payment for Ecosystem Services (PES) and REDD (Reducing Emissions from Deforestation and Forest Degradation) schemes affect rich and poor families differently, leading to unintended consequences such as altered community relationships and patterns of wealth. For example, in China the central government-mandated Sloping

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Land Conversion Program had a significant negative impact on lower income households, substantially altering family dynamics by requiring longer migration stays in urban areas to obtain income (Liu et al. 2008; Li et al. 2011). • Socioeconomic inequality reduces cultural diversity by disempowering, displacing, or destroying the culture of various local ethnic groups (Benhabib 2002). In Amazonian South America, for example, many tribal peoples have been forced off their forested lands and into shantytowns as menial workers to allow logging, mining, or large-scale agricultural interests to take the land (Schmink and Wood 1992; Browder and Godfrey 1997). This diminishes the embedded cultural knowledge about local environment and traditional subsistence approaches that might otherwise have provided good models for communities looking to move towards more sustainable ways of life. • Conflict between groups has been linked to socioeconomic inequality (Lichbach 1989; Ember et al. 1992; Cramer 2003; Peters 2004; Besancon 2005). Needless to say, such conflict makes it less likely that the needed collaboration will take place to resolve joint environmental problems and implement sustainability initiatives. A timely example is that of the conflict between ethnic groups (including immigrant groups) in highly unequal South Africa, which fundamentally harms efforts to develop sustainable development in the large impoverished townships such as Diepsloot (Rogers 2012). • Socioeconomic inequality blocks cooperation, collaborative problem-solving, and needed global accords to address environmental degradation such as biodiversity loss and climate change. This happens through social fragmentation and lack of trust (World Economic Forum 2011; Midlarsky 1999; Daily et al. 1995; Wilkinson and Pickett 2009). Even in the absence of overt conflict, communities and nations are far less likely to cooperate with one another when they are aware that they do not share common interests, benefits, and responsibilities. In other words, even if they were to make an agreement, the various parties would not feel that the allocation of benefits and responsibilities was fair, thereby undermining cooperation. Groups of nations have walked out of multilateral negotiating sessions for this very reason (Pfetsch and Landau 2000; Sanwal 2011). Who would sign an agreement that blocks them from achieving a decent level of development in order to preserve the right to a much higher standard of living by others?

Moving Towards Sustainability “Sustainability” is often an overused but poorly defined concept that allows anyone to see in it what they want. Over the decades, what is meant by “sustainability” has shifted from non-depletion of natural resources, and possibly protection of functioning ecosystems, to a more holistic understanding that incorporates economic stability and, in some cases, a stable social infrastructure that protects human health and well-being.

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The connections between socioeconomic equity and environmental degradation (or protection) outlined in this chapter illustrate that environmental degradation cannot be addressed without also focusing on the social drivers of sustainability. “Social sustainability” means ways of life that are healthy and satisfying for people and communities and thus can be sustained over time. The material, social, and emotional needs essential to human well-being must be met in order for this to be the case (Rogers et al. 2012). Not coincidentally, the changes required to move towards environmental sustainability – a decreased focus on social status and material consumption and a greater focus on equity and human relationships – may also be the best way to increase human well-being (Eckersley 2006, 2011). Improving socioeconomic equality is a critical tool when attempting to map a strategy for shifting societies towards greater sustainability (see the chapter “▶ Mechanisms of Cultural Change and the Transition to Sustainability”). Even with the most enlightened environmental policies in place, without social sustainability the societal foundations of environmental sustainability will eventually erode away through instability, conflict, and social breakdown.

References Acemoglu D, Robinson JA (2012) Why nations fail: the origins of power, prosperity, and poverty. Crown Business, New York Arshad Z (2012) Women’s inequality linked to soaring population. Inter Press Service 09-01-12. www.ipsnews.net/2012/07/womens-inequality-linked-to-soaring-population/ Aydin N (2010) Subjective well-being and sustainable consumption. Int J Environ Cult Econ Soc Sustain 6:133–148 Benhabib S (2002) The claims of culture: equality and diversity in the global era. Princeton University Press, Princeton Besancon ML (2005) Relative resources: inequality in ethnic wars, revolutions, and genocides. J Peace Res 42(4):393–415 Birdsall NM (1988) Fertility and poverty in developing countries. J Pol Model 10(1):29–55 Boyce JK (2003) Inequality and environmental protection. Working Paper Series no. 52, Political Economy Research Institute, University of Massachusetts Browder JO, Godfrey BJ (1997) Rainforest cities: urbanization, development, and globalization of the Brazilian Amazon. Columbia University Press, New York Cole L, Foster S (2000) From the ground up: environmental racism and the rise of the environmental justice movement. New York University Press, New York Cornia GA, Addison T, Kiiski S (2004) Income distribution changes and their impact in the postSecond World War period. In: Cornia GA (ed) Inequality, growth and poverty in the era of liberalization and globalization. Oxford University Press/United Nations University, World Institute for Economics Research, Oxford Cramer C (2003) Does inequality cause conflict? J Int Dev 15:397–412 Daily GC, Ehrlich AH, Ehrlich PR (1995) Socio-economic equity – a critical element in sustainability. Ambio 24:58–59 Easterly W (2002) The elusive quest for growth: economists’ adventures and misadventures in the tropics. MIT Press, Boston Eckersley R (2006) Is modern Western culture a health hazard? Int J Epidemiol 35:252–258 Eckersley R (2011) The science and politics of population health: giving health a greater role in public policy. Public Health 2(3), WMC001697

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Ehrlich P, Holdren J (1971) Impact of population growth. Science 171:1212–1217 Ember CR, Ember M, Russett B (1992) Peace between participatory polities – a cross-cultural test of the democracies rarely fight each other hypothesis. World Polit 44(4):573–599 Eriksson C, Persson J (2003) Economic growth, inequality, democratization, and the environment. Environ Res Econ 25:1–16 Grieg-Gran M, Porras I, Wunder S (2005) How can market mechanisms for forest environmental services help the poor? Preliminary lessons from Latin America. World Dev 33(9):1511–1527 Haughton G (1999) Environmental justice and the sustainable city. J Plann Educ Res 18(3):233–243 Kenworthy L, Pontusson J (2005) Rising inequality and the politics of redistribution in affluent countries. Perspect Polit 3(3):449–471 Klein N (2007) The shock doctrine: the rise of disaster capitalism. Henry Holt, New York Korten D (1995) When corporations rule the world. Kumarian Press/Berrett Koehler, Sterling Kosoy N, Corbera E (2010) Payments for ecosystem services as commodity fetishism. Ecol Econ 69:1228–1236 Kosoy N, Corbera E, Brown K (2008) Participation in payments for ecosystem services: case studies from the Lacandon rainforest, Mexico. Geoforum 39(6):2073–2083 Kosoy N, Brown PG, Bosselmann K et al (2012) Pillars for a flourishing earth: planetary boundaries, economic growth delusion and green economy. Curr Opin Environ Sustain 4:1–6 Li J, Feldman M, Li S, Daily G (2011) Rural household income and inequality under the Sloping Land Conversion Program in western China. Proc Natl Acad Sci 108(19):7721–7726 Lichbach MI (1989) An evaluation of ‘does economic-inequality breed political-conflict’ studies. World Polit 41(4):431–470 Liebig T, Sousa-Poza A (2004) Migration, self-selection and income inequality: an international analysis. Kyklos 57(1):125–146 Liu JG, Li SX, Ouyang ZY, Tam C, Chen XD (2008) Ecological and socioeconomic effects of China’s policies for ecosystem services. Proc Natl Acad Sci 105(28):9477–9482 Magnani E (2000) The Environmental Kuznets Curve, environmental protection policy and income distribution. Ecol Econ 32:431–443 Michael K, Vakulabaranam V (2012) Class inequality and climate change dynamics in India. Planet Under Pressure conference poster presentation, London, 29 March 2012 Midlarsky MI (1999) The evolution of inequality: war, state survival, and democracy in comparative perspective. Stanford University Press, Stanford Morello-Frosch R et al (2002) Environmental justice and regional inequality in Southern California: implications for future research. Environ Health Perspect 10(2):149–154 Nugent JB (1985) The old-age security motive for fertility. Popul Dev Rev 11:75–97 Perkins J (2004) Confessions of an economic hit man. Plume, New York Peters PE (2004) Inequality and social conflict over land in Africa. J Agrar Change 4(3):269–314 Pfetsch FR, Landau A (2000) Symmetry and asymmetry in international negotiations. Int Negot 5:21–42 Rabinowitz D, Lubanov C (2011) Climate justice in Israel: inequality in greenhouse gas emissions from domestic electricity consumption and private car use. The Association of Environmental Justice in Israel (AEJI), Position Paper no.1, January 2011 Rechtschaffen C, Gauna EP (2002) Environmental justice: law, policy, and regulation. Carolina Academic Press, Durham Rogers DS (ed) (2012) Waiting to be heard: preliminary results of the 2012 equity & sustainability field hearings. Initiative for Equality, Occasional Report # 1, Rapid City Rogers DS, Duraiappah AK, Antons DC et al (2012) A vision for human well-being: transition to social sustainability. Curr Opin Environ Sustain 4:61–73 Sanwal M (2011) Climate change and the Rio+20 summit: a developing country perspective. Clim Dev 3:89–93 Schmink M, Wood CH (1992) Contested frontiers in Amazonia. Columbia University Press, New York

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Shaw R (2008) Beyond the fields: Cesar Chavez, the UFW, and the struggle for justice in the 21st century. University of California Press, Berkeley Stark O (2006) Inequality and migration: a behavioral link. Econ Lett 91(1):146–152 Steed B (2007) Government payments for ecosystem services—lessons from Costa Rica. J Land Use 23(1):177–202 Stiglitz J (2003) Globalization and its discontents. Norton, New York United Nations Department of Economic and Social Affairs (2005) United Nations report on the world social situation, 2005: the inequality predicament. United Nations Department of Economic and Social Affairs, New York Veblen T (1899) The theory of the leisure class: an economic study of institutions. Penguin Books, New York Wade RH (2001) The rising inequality of world income distribution. Finance Dev 38(4):567–589 Watts M, Kashi E (2008) Curse of the black gold: 50 years of oil in the Niger Delta. PowerHouse Books, Brooklyn Wilkinson R, Pickett K (2009) The spirit level: why more equal societies almost always do better. Penguin Books, New York World Bank (2011) GINI index, by country. http://data.worldbank.org/indicator/SI.POV.GINI/ World Economic Forum (2011) Global risks 2011. World Economic Forum, Geneva You J, Sanjeev K (2005) A comparative study of inequality and corruption. Am Sociol Rev 70:136–157

Mechanisms of Cultural Change and the Transition to Sustainability

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Cody T. Ross, Peter J. Richerson, and Deborah S. Rogers

Contents Cultural Evolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A Brief Sketch of the Mechanisms of Cultural Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Guided Variation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Biasing Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Success . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Prestige . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Differential Success . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Role of Cultural Evolution in Ecologically Destructive Feedback Loops . . . . . . . . . . . . . . . . . . . . Cultural Evolution Often Leads to Adaptations Which Are Local in Space . . . . . . . . . . . . . . Cultural Evolution Often Leads to Adaptations Which Are Anachronistic . . . . . . . . . . . . . . . Cultural Evolution Generates Coevolutionary Pressure in Other Systems . . . . . . . . . . . . . . . . Cultural Systems Are Prone to Complex Dynamics Like Chaotic Change and Runaway Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Harnessing the Mechanisms of Cultural Evolution to Manifest Beneficial Change . . . . . . . . . . Affecting Individual Decisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Affecting Societal Structures and Institutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Recommended Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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C.T. Ross (*) University of California, Davis, CA, USA e-mail: [email protected] P.J. Richerson Department of Environmental Science and Policy, University of California, Davis, CA, USA e-mail: [email protected] D.S. Rogers Institute for Research in the Social Sciences, Stanford University, Stanford, CA, USA e-mail: [email protected]; [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_63, # Springer Science+Business Media Dordrecht 2014

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Abstract

Humans learn and share information on a massive scale through the use of culture. In this paper, we will outline the mechanisms of cultural evolutionary change, evaluate their role in ecologically destructive feedback loops, and conclude by describing how we might harness the mechanisms of cultural evolution to favor ecologically and socially beneficial change. A virtue of the science of cultural evolution is that it is developed on the same basic framework of ecology and evolution that applies to the natural world, giving it a synthetic role in linking the human behavioral sciences to the natural sciences. Keywords

Cultural evolution • Cultural change • Social learning • Feedback loops • Learning bias • Sustainability

Cultural Evolution Humans learn from one another on a massive scale compared to other animals. This “social learning” is the foundation of culture. Cultural evolution, in the sense we use it, refers to the change in frequency of socially learned traits in populations over time; it is a value-neutral term. Cultural evolution is driven not only by natural selection and random variation but also by individual and collective decision making (Mesoudi et al. 2006). In the context of human behavior, cultural evolutionary theory aims to explain the emergence, persistence, and decline of skills, beliefs, and institutions as they are passed down from one social learner to the next. Culture allows for faster tracking of environmental change and allows for the cumulative evolution of more complex traits than individuals could hope to invent on their own. The cultural transmission of ideas has with no doubt been critical to the radical explosion of cumulative human knowledge, technology, industry, and governance systems. However, the mechanisms of cultural evolution can, at times, lead to radically destructive feedback loops. In this paper, we will outline the mechanisms of cultural evolution, evaluate their role in ecologically destructive feedback loops, and conclude by describing how we might harness the mechanisms of cultural evolution to favor ecologically and socially beneficial change. A virtue of the science of cultural evolution is that it is developed on the same basic framework of ecology and evolution that applies to the natural world, giving it a synthetic role in linking the human behavioral sciences to the natural sciences.

A Brief Sketch of the Mechanisms of Cultural Change Several well-studied mechanisms act as “forces” that cause cultural evolution (Boyd and Richerson 1985). We briefly sketch the most important.

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Guided Variation Over the course of an individual’s lifetime, beliefs and behaviors often change via experience, due to individual learning and invention. For example, a welder may discover a more effective method of welding steel beams together, by either experimentation or accident. Neophyte welders may subsequently learn the improved technique directly from the innovator or through a chain of social learning tracing back to the innovator. In contexts such as the above example, when the strategies innovated in one time period are linked to strategies in a later time period by cultural transmission of knowledge, we say that such change is the result of guided variation.

Biasing Forces Social transmission allows for the inheritance of acquired behaviors, values, and beliefs. Unbiased imitation is the simplest form of social transmission. The strategy in this case is simply to copy the behavior of a random individual in the population. The motivation for this learning strategy is simply to avoid the costs associated with effortful individual learning through trial-and-error experience. On the other hand, one can selectively adopt techniques that seem better by some decision-making heuristic or another, depending on context. The simplest learning bias is to try out two or more cultural variants and preferentially adopt the one that seems to work the best. This bias is based on the actual performance of the variants and is termed a content bias. This learning bias can be costly, however, if the trials are costly or hard to evaluate, much as in the case of guided variation. Several less demanding, but potentially less accurate, biases are frequently involved in social transmission. Three basic ones include:

Conformity When individuals can sample the strategies of more than two targets, they can use the frequency of the observed strategies among the targets to guide which strategy should be adopted. Many processes in nature, including natural selection, content bias, and guided variation, will tend to produce adaptive rather than maladaptive strategies. Thus, a learning bias which favors copying the most common strategy in a population will often yield better results than random imitation. Conformity works well in adapting to spatial variation because conformist learners tend to ignore variation introduced by migrants from different ecologies or societies. On the other hand, conformity is a risky strategy in the face of temporal variation as conformists will also ignore innovators who introduce new adaptations to a changing environment (Nakahashi et al. 2012).

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Success Success-biased transmission of cultural traits occurs when an individual observes two or more variants of a cultural trait and preferentially adopts the trait that yields the highest returns to the people being imitated. For example, an individual in a small-scale fishing society might observe fishermen on several different trips, keeping track of the type of lures being used, and then preferentially adopt the lure that was most effective at catching fish. Success-biased transmission generates a dynamic which is very similar to that of natural selection over a broad range of conditions but can be much faster. When individuals’ estimates of success are noisy or biased, this strategy is problematic.

Prestige Prestige-biased transmission involves the copying of a diverse array of traits possessed by prestigious or culturally successful individuals. Determining who is successful in a society is much easier than determining specifically what traits have led them to success. By copying an array of traits which covary with prestige or success, one stands a chance of copying the correct traits that give rise to success. This learning bias is quite interesting in that it may allow neutral and even maladaptive traits to hitchhike along with adaptive cultural traits. When the standards of what constitutes success are themselves culturally transmitted, this mechanism can lead to quite pathological results; the consumption-based status competition of the modern world is an important example.

Differential Success Natural selection operates on cultural variation just as it does on genetic variation. Selection on culture also operates at different levels. On the group level, if a trait of interest covaries with a group or institution, then the differential success or failure rates of groups or institutions can have an effect on the frequency of such a trait over time. For example, the beliefs of North American Anabaptists and a few other religious groups cause them to resist the demographic transition and continue to have a high birth rate. As a result, these beliefs are increasing rapidly due to differential biological and cultural reproduction. The evolution of cultural traits due to the differential success of groups or institutions can proceed due to selection (if the cultural trait gives groups an advantage in competitions with other groups) or due to drift (if the cultural trait confers no fitness costs or benefits, but other aspects of the groups cause the differential success of groups). Sometimes the rate of extinction of unsuccessful groups and the proliferation of successful ones can be

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quite rapid. For example, small businesses are formed in many economies at high rates. Most of them fail, but a few succeed and grow large or spin off many daughter firms. This mechanism of cultural change can be quite relevant to ecological destruction, if the behavior that allows one company to outcompete other companies involves profit-maximizing but ecologically destructive actions, such as the illegal disposal of chemical waste.

Role of Cultural Evolution in Ecologically Destructive Feedback Loops Cultural evolution emerges from a powerful set of mechanisms for rapidly generating complex adaptations. However, it is hardly foolproof. In this section, we will briefly detail the ways in which cultural evolution can play a role in ecologically destructive behaviors.

Cultural Evolution Often Leads to Adaptations Which Are Local in Space In the absence of effective large-scale institutions, cultural adaptations at small scales often create the familiar tragedy of the commons. For example, intense interfirm competition will favor businesses that pollute if societies fail to establish an institutional playing field that prevents firms from profiting from environmental or social abuses. The evolution of modern lobbying techniques in the USA is an example of how intense interfirm competition can subvert the policy-making process. Global-scale problems are especially difficult to redress because global institutions are relatively weak compared to national ones.

Cultural Evolution Often Leads to Adaptations Which Are Anachronistic In principle, we can understand something about the future, as in the case of global warming, and institute changes to respond to opportunities and threats that have not yet happened. Despite this fact, the belief systems and institutions inherited via cultural transmission are the result of evolution in past environments and frequently lead to behaviors which may be maladaptive in the present and future. Additionally, behaviors which maximize survival or profit in the short term may in fact be horrendous strategies in the long term. Conversion of rainforest to cattle pasture in Costa Rica is an example of this problem; pasturelands offered high profits in the short term but quickly became barren savannas, as limited nutrient stores rapidly leached from weathered topsoils.

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Cultural Evolution Generates Coevolutionary Pressure in Other Systems The use of pesticides by companies or farmers often leads to increased yields and profits in the short term and manages the risk of crop failure. The strategy of pesticide use will thus be favored by innovation, by biased transmission of strategy, and by the differential success of farmers. The heavy use of pesticides, however, leads to numerous consequences including the evolution of pesticide-resistant pests, the disruption of ecosystems, and biodiversity loss. The evolution of pesticide resistance and the destruction of natural food chains may serve to exacerbate pest problems in the future.

Cultural Systems Are Prone to Complex Dynamics Like Chaotic Change and Runaway Processes We have already mentioned how cultural evolution of prestige can result in runaway status competitions. American consumerism is a classic example; advertising campaigns and social norms link love, friendship, and prestige with gifting large quantities of mass-produced goods. Thus, the behaviors necessary to maintain social relationships, attract mates and business partners, or improve one’s status are often linked to large ecologically destructive externalities and unnecessary waste.

Harnessing the Mechanisms of Cultural Evolution to Manifest Beneficial Change Cultural evolution is frequently a powerful process, and our policy tools to influence it are often feeble. Adding evolutionary theory to the policy analysis toolkit should help to improve policy recommendations (Richerson et al. 2006). Given that we desire to prevent environmental and social harms that we have good reason to know exist or will come to pass, how might we derive practical tools from cultural evolutionary theory, to address these concerns? Several major issues should be addressed to foster socially and environmentally beneficial policy: 1. Time scales must be reevaluated. Current policy tends to focus on short-term effects, and long-term-term effects are marginalized. 2. The scope of outcomes from policy must be reevaluated. Policy and law often have come to protect the interests of the wealthy and powerful over the interests of the public and the environment. 3. Institutional incentives and constraints must be reevaluated. Current corporate, political, and legal structures and institutions motivate unsustainable choices. 4. Linkages (often irrational) between various activities, roles, beliefs, motivations, constraints, and outcomes must be reevaluated. Blood diamonds and plastic

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waste are symbols of love, and gas-guzzling SUVs with “We support our troops” stickers are symbols of patriotism. An integrative intervention policy, which seeks to foster positive social and environmental behavior change, must aim to change both the attitudes and decisions of individuals as well as social structures and institutions.

Affecting Individual Decisions 1. We need to understand the persuasion strategies that have proven useful in the business and marketing worlds, such as, using famous and prestigious people to model sustainable behaviors. For instance, research suggests that Brazilian telenovelas have played a substantial role in shifting ideas regarding reproduction, gender, and family planning (Newson et al. 2005). 2. Cultural success and the components of “high status” need to be redefined. Current cultural trends link costly signaling and excess to prestige and success. It certainly remains possible to associate sustainability with prestige and market image, both in the business world and in our personal lives. 3. Sustainability needs to be framed in a nonpartisan light. Secular and religious or liberal and conservative values can be interpreted in ways that promote social and ecological sustainability. Secular institutions, like universities, and religious institutions both have a critical role to play in shaping the values of their audiences. Likewise, liberal and conservative and secular and religious individuals need to hold their representatives accountable for their actions and force organizations to respect the values of their communities.

Affecting Societal Structures and Institutions 1. The time scale of concern need to be reevaluated in policy discussions. Our current dialogue surrounding elections and our methods of evaluating politicians is often based on incredibly short-sighted performance. In such a context, borrowing against the future to gain popularity in the present is an effective career strategy for a politician or business executive, albeit one with horrendous long-term consequences. 2. Externalized costs (e.g., environmental and social harms) need to be accounted for in the price of products and services. These negative externalities do not normally end up represented in the prices of products because the associated costs are normally passed off into the community due to weak laws and powerful corporate lobbying. The price of conventionally farmed food does not include the environmental costs associated with ground water pollution, since there is no real mechanism by which the affected community can challenge such practices. The Pagos por Servicios Ambientales program in Costa Rica is a program which seeks to do this, in a way that both an Ayn

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Randian capitalist and a Greenpeace environmentalist would deem morally acceptable. The program acknowledges that our use of fossil fuels has a negative impact on the environment of our peers and levies a tax on its sale; this tax is then used to pay land owners for land-use strategies which capture the carbon released by the fossil fuels. This program establishes a freemarket trade system which internalizes the negative externalities normally associated with environmental destruction. While the basic science of cultural evolution is fairly well developed, the applied science of cultural evolution is in its infancy. We hope to have convinced our readers that the applied science is worth pursuing.

References Boyd R, Richerson PJ (1985) Culture and the evolutionary process. University of Chicago Press, Chicago Mesoudi A, Whiten A, Laland KN (2006) Towards a unified science of cultural evolution. Behav Brain Sci 29:329–383 Nakahashi W, Wakano JY, Henrich J (2012) “Adaptive social learning strategies in temporally and spatially varying environments.” Hum Nat 23(4):386–418 Newson L, Postmes T, Lea SEG, Webley P (2005) Why are modern families small? Toward an evolutionary and cultural explanation for the demographic transition. Pers Soc Psychol Rev 9:360–375 Richerson PJ, Collins D, Genet RM (2006) Why managers need an evolutionary theory of organizations. Strat Organ 4(2):201–211

Additional Recommended Reading Gintis H (2007) A framework for the unification of the behavioral sciences. Behav Brain Sci 30:1–61 Herrmann B, Tho¨ni C, Ga¨chter S (2008) Antisocial punishment across societies. Science 319:1362–1367 McElreath R, Henrich J (2008) Modeling cultural evolution. In: Dunbar RA, Barrett LA (eds) Oxford handbook of evolutionary psychology. Oxford University Press, Oxford, pp 555–570 Mesoudi A (2011) Cultural evolution: how Darwinian theory can explain human culture & synthesize the social sciences. University of Chicago Press, Chicago Ostrom E, Dietz T, Dolsak N, Stern PC, Stonich A, Weber EU (eds) (2002) The drama of the commons. National Academy Press, Washington, DC Richerson PJ, Boyd R (2005) Not by genes alone: how culture transformed human evolution. University of Chicago Press, Chicago Whitehead H, Richerson PJ (2009) The evolution of conformist social learning can cause population collapse in realistically variable environments. Evol Hum Behav 30:261–273

Knowledge, Learning, and Societal Change for Sustainability

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Chris Blackmore

Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What Is Societal Change for Sustainability? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A Need for Knowing, Acting, and Learning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Social Learning Is Particularly Relevant to Action for Societal Change . . . . . . . . . . . . . . . . . . . . . Understandings of Learning and its Role . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . How Can Different Ways of Knowing and Learning Be Recognized? . . . . . . . . . . . . . . . . . . . . . . . How Can Learning for Societal Change and Sustainability Be Enhanced? . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

What are the roles of knowledge, learning, and societal change in making transitions to sustainability, and how are these concepts related? The viewpoint that individuals, groups, and potentially societies can learn their way to sustainability is explored here. Knowing and learning about sustainability do not necessarily lead to action even if it is desired, because individuals’ and groups’ abilities to act are often constrained by other societal factors. Yet some kinds of learning do appear to be more likely to lead to multi-stakeholder, multilevel changes than others. In recent years, researchers have come to understand how learning for sustainability might be enhanced, with a particular focus on the kinds of social learning that lead to collective and concerted action. Much remains to be understood about how this kind of learning might affect the societal level. There are many different kinds of knowing and learning, and it is important to be able to recognize them and their roles to be able to understand what is most relevant in a particular situation.

C. Blackmore Communication and Systems Department, The Open University, Milton Keynes, UK e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_64, # Springer Science+Business Media Dordrecht 2014

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Keywords

Knowledge • Learning • Societal change • Social learning

Definition Distinctions of knowledge, knowing, and learning and the relationships among them are contested. Knowledge can refer to familiarity, understanding, or awareness of something or sometimes to information or skills. Learning usually refers to a process of transformation from one state of knowing, behaving, or acting to another. It can also be thought of as acquiring knowledge or skills. Societal change can refer to major revolutions or to more subtle and incremental changes in how people behave, including social movements. A society is usually defined by relationships and by geography. It is a large-scale social group that shares a way of life – politically, institutionally, and culturally.

What Is Societal Change for Sustainability? Striving for sustainability involves both learning and change at different levels, ranging from local to global. At the level of societies, change can happen suddenly or gradually and involves changes at other levels ranging from individuals through communities to regions. Societal change is associated with large-scale change, including political, institutional, and cultural dimensions. Consider, for instance, efforts made by local communities, nongovernmental organizations, businesses, and governments in Indonesian Papua to address illegal logging of merbau, a tropical hardwood used for flooring (E.I.A. 2005, 2008). There are many contributing factors that can lead to illegal logging, including consumer practices in other parts of the world, difficulties in enforcing legislation at local and international levels, and issues of land tenure. In this case, the opportunity for sustainable livelihoods was being taken away from the local Kanesaimos tribe, whose ancestral forestland was being exploited. Societal change in Papua away from sustainability was occurring partially as a consequence of the logging. With international attention drawn to this situation by a campaigning organization, the Environmental Investigation Agency, government forces intervened to reduce the logging. This case highlights the need for more than one society to change to more sustainable practices. Businesses in China and in Europe were among those involved in procuring and selling the illegal timber, some knowingly and some unknowingly because of mislabelling. This case also raises questions about the understandings and values of those purchasing the end products and whether they might change if they developed better understandings of the effects of those actions.

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A Need for Knowing, Acting, and Learning From the above example, it can be seen that societal changes for sustainability can range from changes in political decision-making, policy, and enforcement to changes in purchasing behavior. Whether seeking alternatives to fossil fuels, developing policies or legislation to help ensure fair use of natural resources, or negotiating to reduce wastes, a key challenge for sustainable futures is to bring about both knowing and acting, not just one or the other (IHDP 2011). Actions such as using biofuels or recycling glass bottles in practice might not address issues of consumption or wastes because they have unintended consequences, e.g., for food security and for use of energy (Jones et al. 2011). In cases such as these, actions often need to be better informed. Yet, what and whose values and knowledge comes to the fore to inform action in a society is by no means straightforward, and knowing does not always lead to action. For instance, individuals with particular livelihoods (e.g., fishing) or preferences (e.g., to use a car) might well know that their practices cannot be sustained in the long term, but remain unwilling or unable to change their behavior. As in the case of illegal logging in Papua, structural, institutional, or particular powerful interests can prevent changes for sustainability or lead to changes away from sustainability. In Papua, it was not that the Kanesaimos people did not know how to live sustainably, but that they were being prevented from doing so by other more powerful factions in a broader society. Although there is a range of viewpoints on how behaviors change, information and knowledge are generally perceived as having key roles in bringing about certain kinds of societal change, hence the terms “information society” and “knowledge society” that have emerged in the discourse about transforming the ways that societies work. Information and knowledge are often used interchangeably, but there is a well-recognized taxonomy that distinguishes them as a continuum from data, to information, to knowledge, to understanding, to wisdom (Zeleny 1987; Ackoff 1989), with a deepening process of engagement and finding meaning, often called learning.

Social Learning Is Particularly Relevant to Action for Societal Change One particular form of learning that has relevance to action for societal change is social learning. In practice, meanings of social learning range from the way individuals learn in a social context to the way groups of people share processes of learning to achieve particular individual or collective outcomes. The Papua example of illegal logging had many facets, but one of them was undoubtedly about learning both what was going on regarding a scarce resource and how to improve the situation for local communities.

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Another example comes from the management and sustainable use of water at the catchment scale. Social learning in this case typically involves individuals and multi-stakeholder groups becoming more aware of the way in which they use water and for what purposes and then changing their practices (Ison et al. 2007). What counts as sustainable in a particular area varies. Water catchments such as those of the Nile and the Rhine cross national boundaries where there are diverse biophysical and climatic factors, societies, and cultures. People in different areas are therefore not necessarily able to identify a common set of changes that are both systemically desirable and culturally feasible, as they have different sets of interest. However, in developing trans-boundary cooperation, common principles can be identified that are in line with values associated with sustainability, such as not wasting or polluting water and acting with awareness of how one’s use of water affects others. There are many examples of multi-stakeholder, multilevel dialogue processes that have led to concerted action for more integrated management and sustainable use of water (e.g., see EUWI 2011; Mostert et al. 2008; Jiggins et al. 2007). The dynamics of these processes and their contexts are experienced as complex, particularly as some communities are experiencing increased occurrence of droughts or floods with climate change. How initiatives that help foster social learning may contribute to long-term and large-scale societal change for sustainability has yet to be fully appreciated. However, there has been increasing recognition that in complex and messy situations such as management of scarce natural resources, stakeholders need to develop shared knowledge and understanding and harmonize their actions, drawing on their different ways of knowing. This kind of social learning requires interaction both across and within levels of a hierarchy. This interaction does not happen automatically as a result of participation, but needs active and purposeful facilitation. This is because existing power dynamics and patterns of interaction can constrain or even prevent the multilevel interactive learning processes that social learning requires (Woodhill 2002; Blackmore 2010). Much remains to be understood about how the various learning processes of different groups affect the societal level in the longer term. One possibility is that societal change for sustainability may occur when a critical mass of individuals and groups at different levels have reached particular action-oriented outcomes in a concerted way.

Understandings of Learning and its Role It is important to be able to recognize the different kinds of knowing and learning and their roles in order to understand which kind of learning is most relevant in a particular situation. Ideas about learning can be traced back to very early philosophers, psychologists, biologists, and teachers who were interested in how learning took place or how to create the circumstances for it to happen. Over 2000 years ago, Plato believed knowledge was innate and inherited, while Aristotle believed that it came from sensory experience. Behavioral psychology and biology

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informed understandings of learning from the early nineteenth century on. Darwin was among those who influenced learning theories with his insights into the ability of behavior to adjust to environment and into biological continuity in the development of humans and nonhuman animals (Blackmore 2007). Ideas about the mental processes associated with knowing (cognition) came later in the early twentieth century, for instance, with the work of the developmental psychologist Piaget. These insights and many others informed and continue to inform formal education. Over time, learning has become a concern of a much broader range of disciplines, including neuroscience, computer and information science, sociology, political science, behavioral science, cultural anthropology, management science, genetics, rural development, natural resource management, and many different disciplines of education. Cybernetics, which is often associated with engineering as it concerns systems, communication, regulatory feedback, and control, has been particularly influential. First-order cybernetics assumes an observer can stand outside a situation and take an objective view. This position is consistent with traditional behaviorist theories of learning. More recently, second-order cybernetics, which recognizes an observer as part of what is being observed and individuals as structurally coupled with their environments, has led to a new generation of learning theories that are consistent with constructivist views of learning (discussed later in this chapter). Seeing learning or knowing as a particular construct or model (rather than claiming learning or knowing “is” a fixed process out there in the world) is in keeping with second-order and constructivist traditions. In the context of sustainability, accepting the structural coupling of individuals with their environments can be particularly meaningful when considering how human behavior affects and is affected by those environments. It can therefore be tempting to adopt secondorder and constructivist theories uncritically. However, these theories of knowledge and learning are models and have their strengths and limitations. Rather than adopting only one theory, it can be useful in discourses and practices of sustainability to recognize and make explicit how different views of knowledge and learning are being used. This process can be important in facilitating communication and building understanding within a group.

How Can Different Ways of Knowing and Learning Be Recognized? In order to be able to draw on different ways of knowing and learning, there is a need to recognize them. It is important to understand which theories or models of learning and knowing are in use, as they underpin what researchers choose to observe and what they ignore when they try to understand the way individuals or collectives adapt to or anticipate change and transform their practices (Blackmore et al. 2012). There are many different theories about knowledge and learning, some of which focus on learners, some on knowledge, and others on the dynamic relationship between learners and their environments. In contemporary society,

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therefore, many different theories of knowing and learning therefore underpin our assumptions and mental models. Blackmore (2007) considered 24 theories or models of learning and found that each of them could be used to raise different questions about learning in environmental contexts. Understanding learning from an “instructivist” perspective, for instance, tends to assume that knowledge can be transferred from one person to another. A “constructivist” view of learning, on the other hand, assumes that knowledge is not given but instead is developed, with individuals constructing their own knowledge and understanding of the surrounding world through learning. The idea of “co-construction” of knowledge and “social constructionism” goes a step further to assume that learning occurs socially, not just individually. All these ideas have potential roles in gaining insights into sustainability, but these roles vary. For example, Blackmore (2009) considered how these views of learning applied in managing areas of woodland in more sustainable ways. In one small privately owned wood in UK, managing involved the need to develop some basic skills in using tools and interpreting the site to visitors. Instruction clearly had a role in helping to develop such skills. Yet in another woodland area, the New Forest in the south of England, the task of managing also involved developing an understanding of the perceived purposes and priorities for the woodland and negotiating a way forward among a range of different stakeholders regarding conservation, access for recreation, and production of timber. In this case, different perspectives needed to be explored and brought together for a group to learn its way forward, so a social constructionist view of knowledge seemed to prevail.

How Can Learning for Societal Change and Sustainability Be Enhanced? Sterling (2003, p. 205) uses the term “education for change” to mean the role of educational practice in bringing about purposeful change. In this sense, learning for societal change and sustainability is concerned with ways in which learning brings about purposeful change of relevance to sustainability. This kind of learning can be both formal and informal. Formal contemporary curricula are no longer the exclusive domain of conventional educational organizations. Providers of courses and programs for sustainability are broad ranging, including both public and private sectors as well as nongovernmental organizations. The United Nations Decade of Education for Sustainable Development (2005–2014, DESD) has as its stated goal: . . . to integrate the principles, values, and practices of sustainable development into all aspects of education and learning (UNESCO 2009).

Such integration requires a bringing together of theory, practice, and information from a wide spectrum of disciplines. Many claims have been made that learnercentered, problem-based, and project-based approaches offer a great deal in this respect (e.g., Olesen and Jensen 1999; Savery 2006). But designed courses and

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programs are just a part of the overall picture of learning. Learning for societal change and sustainability inevitably involves seeing the world differently and acting on new understandings. Bawden (2010) sees one of the main factors that constrain social learning as being our assumptions about the nature of knowledge and knowing, which has a major influence on our worldviews and our ability to learn how to learn. Snyder and Wenger (2004) view our world as a learning system, claiming that “developing and disseminating certain kinds of knowledge depends on informal learning much more than formal – on conversation, storytelling, mentorships, and lessons learned through experience.” They advocate development of Communities of Practice (CoPs) as a good way of informal learning for societal change. As can be seen from this chapter, the relationship between knowledge, learning, and societal change has many facets, each of which has a role to play in making the transition to sustainability.

References Ackoff RL (1989) From data to wisdom. J Appl Syst Anal 16:3–9 Blackmore C (2007) What kinds of knowledge, knowing and learning are required for addressing resource dilemmas? A theoretical overview. Environ Sci Policy 10(6):512–525 Blackmore C (2009) Learning systems and communities of practice for environmental decision making. Ph.D. Thesis, The Open University, Milton Keynes. Abstract available from http:// oro.open.ac.uk/21586/ Blackmore C (2010) Managing systemic change: future roles for social learning systems and communities of practice? In: Blackmore C (ed) Social learning systems and communities of practice. Springer, London, pp 201–218 Blackmore C, Cerf M, Ison R, Paine M (2012) The role of action-oriented learning theories for change in agriculture and rural networks. In: Darnhofer I, Gibbon D, Dedieu B (eds) The farming systems approach into the 21st century: the new dynamic. Springer, London Environmental Investigation Agency (2005) The last frontier – illegal logging in Papua and China’s massive timber theft. Film and report available at http://www.eia-international.org/ the-last-frontier. Accessed 29 Feb 2012 Environmental Investigation Agency (2008) Buyer beware – an investigation into merbau wood flooring sales in the UK. Report available at http://www.eia-international.org/buyer-beware-2. Accessed 29 Feb 2012 European Water Initiative (EUWI) (2011) Annual report 2011. Available via http://www.euwi.net/ . Accessed 21 Dec 2011 International Human Dimensions Programme (2011) Knowledge, learning and societal change. Final draft – science plan for a cross-cutting core project of the International Human Dimensions Programme on Global Environmental Change. IHDP, Bonn Ison RL, Ro¨ling N, Watson D (2007) Challenges to science and society in the sustainable management and use of water: investigating the role of social learning. Environ Sci Policy 10(6):499–511 Jiggins J, van Slobbe E, Ro¨ling N (2007) The organisation of social learning in response to perceptions of crisis in the water sector of the Netherlands. Environ Sci Policy 10(6):526–536 Jones A, Pimbert M, Jiggins J (2011) Virtuous circles: values, systems and sustainability. IIED and IUCN CEESP, London Mostert E, Craps M, Pahl-Wostl C (2008) Social learning: the key to integrated water resources management? Water Int 33(3):293–304

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Olesen HS, Jensen JH (1999) Project studies – a late modern university reform? Roskilde University Press, Frederiksberg C Savery JR (2006) Overview of problem-based learning: definitions and distinctions. Interdiscip J Probl Based Learn 1(1):9–20 Snyder WM, Wenger E (2004) Our world as a learning system: a communities-of-practice approach. In: Conner ML, Clawson JG (eds) Creating a learning culture: strategy, technology and practice. Cambridge University Press, Cambridge, pp 35–58 Sterling S (2003) Whole systems thinking as a basis for paradigm change in education: explorations in the context of sustainability. Ph.D. Thesis, University of Bath, Bath UNESCO (2009) United Nations Decade of Education for Sustainable Development [online], http://portal.unesco.org/education/en/ev.php-URL_ID¼27234&URL_DO¼DO_TO PIC&URL_SECTION¼201.html. Accessed 22 Dec 2011 Woodhill J (2002) Sustainability, social learning and the democratic imperative. Lessons from the Australian Landcare movement. In: Leeuwis C, Pyburn R (eds) Wheelbarrows full of frogs – social learning in rural resource management. Koninklijke Van Gorcum BV, Assen, pp 317–331 Zeleny M (1987) Management support systems: towards integrated knowledge management. Hum Syst Manag 7(1):59–70

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Contents Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Key Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Limitations of Existing Institutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Civil Society . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Public Sphere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Engaging Citizens Effectively . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Civic Engagement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Envisioning an Ecologically Sustainable Society . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Abstract

As environmental degradation has accelerated, it is becoming increasingly apparent that our existing social institutions are incapable of generating and sustaining actions necessary to meaningfully address this issue. Because civil society stands outside of the dominant logics of the economy and the nation state, it provides a location for the generation and advocacy of innovative actions. To foster and engage civil society in taking these actions, we need to address several issues. First, there is a need for a broad-based democratization of the political arena, so that citizens can meaningfully participate in their own governance. Second, the means by which information regarding the state of environmental degradation is communicated needs to shift toward challenge campaigns, in which the dire status of the environment is openly acknowledged, and the capacity for citizen initiatives is encouraged. Finally, an alternative vision of an ecologically sustainable society needs to be developed to serve as

R.J. Brulle Department of Culture and Communications, Drexel University, Philadelphia, PA, USA e-mail: [email protected] Bill Freedman (ed.), Global Environmental Change, DOI 10.1007/978-94-007-5784-4_65, # Springer Science+Business Media Dordrecht 2014

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an inspiration in the formation of social movements capable of effecting social change. Thus democratic action by civil society plays a critical role in developing the capacity to guide our economic and administrative systems toward sustainability. Keywords

Civil society • Social movements • Social learning • Public sphere • Democratic deliberation • Threat messages • Challenge messages

Definition Civil society is constituted by interactions that take place outside of either market or government interactions, and is comprised of a number of both formal and informal organizations, including interest groups, churches, voluntary groups or charitable organizations.

Key Information To foster meaningful actions to address sustainability, the institutions of civil society, in the form of social movements, are a necessary component to offset the institutional limitations of the global economy and the nation state. The scientific evidence on the state of the natural environment is clear. It conclusively shows that we are very near to or exceeding critical environmental thresholds. The implications of this situation for environmental policy are clear. The existing approaches are proving to be inadequate to the task at hand. Thus there is a need to move beyond the current incremental approaches and toward the development of rapid and significant actions that are necessary to deal with issues such as global climate change, ocean acidification, or the massive losses in global biodiversity. The question that emerges is how can we best engage society in the difficult socioeconomic transitions that are necessary to effectively deal with global change? This will require a rethinking and reorientation of global environmental efforts to develop a more efficacious political practice that can rapidly accelerate the pace and scope of institutional efforts to create a sustainable society.

Limitations of Existing Institutions Implementation of the necessary actions depends on the “political will” of decisionmakers and the ability of the dominant institutions to undertake large-scale reform. However, the very nature of the existing economic and political institutions limits actions within a narrow range that precludes implementation of efforts at the scale or scope necessary to adequately address ecological degradation. As the modern social order developed, the coordination of production and exchange via traditional action

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and barter was replaced by the market. Similarly, administrative state power developed as a means of ensuring the operation of and stabilizing the effects of the economic system. Thus productive activity became coordinated through the steering mechanisms of money and power carried out in the institutions of the market and the state (Habermas 1987: 186–187). These political and economic institutions constrain policy within parameters defined by their key imperatives. For the market, this is the necessity to maximize return on investment through the continuous economic expansion. For the state, this entails providing security, ensuring economic growth, and maintaining its political legitimacy. Accordingly, environmental actions that impinge on any of these imperatives will not be fostered within the dynamics of the market or the state. Rather than transforming economic and political institutions to meet ecological limitations, this dynamic forces environmental policies to fit into the maintenance of existing institutions (Brulle 2000; Bernstein 2001: 178–179). Thus our society’s capability for self-correction is systematically limited by the institutions of the capitalist world economy and the nation state. This greatly restricts the range of possible policy considerations, such as global governance or moving from an economy centered on status consumption to providing for human satisfaction.

Civil Society Civil society is constituted by interactions that take place outside of either market or government interactions. It is comprise of a number of both formal and informal organizations, including interest groups, community associations, cultural organizations, churches, and charitable organizations. Institutions of civil society constitute a vital communicative link between citizens and government and are a key site where large-scale social change originates. Civil society is constituted by voluntary institutions that exist outside of the direct control of both the market and the state (Alexander 2006). Because they are based in communicative action, they constitute a means to identify and propose solutions to social and environmental problems, unhindered by the constraints affecting economic and political institutions. The capability of a society to learn and respond to changed conditions is dependent upon the generation of alternative world views, their open communication into the general stock of cultural knowledge, and the use of this knowledge in development of new social arrangements. The independence of civil society forms a key component of this sector’s capacity to serve as a site for the generation of social change. A key action that originates in civil society for the promotion of social change is the formation of social movement organizations. A social movement organization enables individuals to join together with other members of their community to participate meaningfully in their own governance. Perhaps the most well-known effort was the founding of the Sierra Club by John Muir. This was one of the earliest efforts of citizens to change government policies related to the natural environment. Such efforts allow individual citizens to translate their everyday concerns into collective issues and then press the government and economic institutions to address these concerns.

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The Public Sphere The effective translation of these alternatives into the public dialogue requires the operation of a democratic public sphere. The public sphere is the arena in which citizens have historically exerted their influence over collective decisions. The role of the public sphere is to serve as an arena which can “subject persons or affairs to public reason, and to make political decisions subject to appeal before the court of public opinion” (Habermas 1989: 141). Thus the public sphere constitutes a communicative structure and functions as an arena in which the institutions of civil society can identify problems, develop possible solutions, and create sufficient political pressure to have them addressed by constitutional governments (Brulle 2000). These new worldviews and social institutions can then successfully adapt our existing social institutions to changed conditions. Accordingly, social movement organizations form a critical communicative link between citizens and the public sphere. These organizations enable individuals to join together with other members of their community to meaningfully participate in their own governance (Rochon 1998: 137). This link between individual experiences and social movement organizations “ensures that newly arising situations are connected up with existing conditions” (Habermas 1987: 140). Thus the capability of a society to learn and respond to changed conditions is dependent upon the generation of alternative world views, the open communication of these realities into the general stock of cultural knowledge, and the use of this knowledge in development of our social institutions. Enabling Role of Institutions of Civil Society to Bring About Social Change: An Example from the USA In the spring of 1978, the residents of Love Canal,

New York, discovered that their neighborhood was built on top of a toxic wastedump containing 21,000 tons of hazardous chemical waste. Through the door-to-door efforts of the community residents, led by Lois Gibbs, the community organized around this issue and formed the Love Canal Homeowners Association. This association, with local scientific assistance from volunteers at nearby universities, conducted health monitoring studies documenting the disastrous health consequences of this situation on the people who lived in that neighborhood. It also advocated for evacuation of all of the residents from the hazardous area. Finally, after numerous political actions, including holding two EPA officials hostage, and demonstrating outside of the 1980 Democratic National Convention, the Federal Government funded the permanent relocation of the residents of this neighborhood in 1980. This action by the Love Canal Homeowners Association placed the issue of toxic waste dumps on the national political agenda and gained recognition of the health issues associated with this issue. The Congress responded quickly to this situation, and passed the Comprehensive Environmental Response, Compensation, and Liability Act in 1980, which established the EPA Superfund program. –Robert J. Brulle

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Engaging Citizens Effectively For the institutions of civil society to be effective in fostering social change, choosing effective methods to engage citizens is essential. First, a participatory structure is critical in large-scale social change efforts. Through participation in collective decision-making processes, citizens acquire the necessary technical and cultural knowledge to make a meaningful contribution. Participating in deliberative collective decision-making processes involves a process of moral development away from a narrow individualism and toward a more encompassing notion of morality. It also enhances civic participation and motivates further political action (Fischer et al. 2012). Second, appropriate communication methods are important to foster social change. The political and economic imperatives constraining formal institutions are constantly reinforced through communication channels such as news, advertising, or political campaigns. For example, the recent debate regarding action over climate change was dominated by neoliberal proposals, such as the formation of green jobs and economic growth, as an answer to climate change. Not only is the viability of green jobs problematic, but this approach advocates continued economic expansion as an answer to climate change. While this fits within the established political and economic imperatives, this strategy runs counter to many analyses that show the great difficulty in disconnecting the link between economic expansion and environmental degradation (York et al. 2003). This poses major challenges to the institutions of civil society, whose voices are easily lost in a culture that places a high value on the imperatives of the state and the economy. Different institutions of civil society advocating more sustainable human behaviors use various methods to communicate their message to citizens. Three types of messaging may be distinguished. Reassuring messages focus on a lowest common denominator acceptable to all citizens. Reassuring messages are widely used but have limited ability to encourage fundamental change. Threat messages, by contrast, can enhance the focus of individuals on collective action to avert the threat. However, if the threat is considered to be beyond the resources available to cope with it, threat messaging is not effective. Challenge messaging therefore may be the most effective means of communicating the need for changes in human behavior. It occurs where the perceived danger that is being communicated does not exceed the perceived ability to cope and thus can foster the creation of ideas and actions that can strengthen the resilience and creativity of society. Thus, while fear appeals can lead to maladaptive behaviors, fear combined with information about effective actions can be strongly motivating (Brulle 2010). Enabling Role of Institutions of Civil Society to Bring About Social Change: A Global Example The global trade and dumping of hazardous waste emerged

as a public concern in the late 1980s and early 1990s. One of the first such incidents that put this issue on the public agenda occurred when,

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in December 1987, a ship carrying toxic incinerator ash from the city of Philadelphia dumped several tons of that cargo on a beach at Gonaives, Haiti. Many observers believed this was a clear case of environmental racism as Haiti was the poorest nation in the western hemisphere and the US was the wealthiest nation in the world. Soon afterward, Haitian and Haitian-American organizations such as the Haiti Communications Project and the Collective for the Protection of the Environment and Alternative Development teamed up with groups in the global North including Greenpeace, Global Response, and Witness for Peace to create an international coalition called Project Return to Sender. The coalition’s name signaled its goal as well as a new movement tactic that centered on the logic of accountability: those nations that produced the waste should have to take it back and manage it responsibly. In 2002, after a decade and a half of international activist campaign work, the waste was finally returned to the U.S. Over the years, activists involved in this effort were able to draw on the discourse of environmental justice and use the growing body of research on environmental racism as a critical resource. The Philadelphia/Haiti case was arguably the first major conflict that announced the presence of a burgeoning global movement for environmental justice. Today, numerous groups count themselves as inheritors of the legacy of the work begun by Project Return to Sender activists. For example, the International Campaign for Responsible Technology, the Global Alliance for Incinerator Alternatives, and the Basel Action Network now operate on the models and examples set by Project Return to Sender. –David Pellow

Civic Engagement While changing the content of environmental messages, it is also critical to adopt another form of communication. Rather than one-way communications, what is needed is a communications process that promotes civic engagement and dialogue. When individuals are provided with full information regarding a particular risk and are then included in the development of responses to it, they are much more likely to engage in taking action than when only given limited information or responsibility. This defines a new approach to environmental communications. Rather than just informing the public and eliciting support for various elite policy positions, environmental communications needs to aim at developing messaging procedures that involve citizens directly in the policy development process. There is also a large amount of research on public involvement in environmental decision-making that could be applied to this task. Individuals working in this area have developed and tested a decision-making process which integrates scientific analysis and community deliberation into a comprehensive strategy for environmental decision-making. Known as analytic deliberation, this process defines

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a democratic method for development of government policies that recognizes the link between social rationality and public involvement. It also provides techniques for integrating practical, normative, and aesthetic concerns into a democratic decision-making process (NRC 1996). This approach can help inform the creation of democratic environmental communications that builds civic engagement.

Envisioning an Ecologically Sustainable Society One of the keys to citizen action is the belief that credible alternatives to the existing situation exist. While the scientific analysis of environmental problems has developed a strong critique of the ecological impacts of our current social order, this alone is not sufficient to develop a credible alternative vision on which an ecologically sustainable society can be based. Large-scale social change is based on the creation of a rhetoric of “salvation.” It contains an analysis of how we entered into our current problematic situation and how “evil” it is. It then projects how we can work to move ourselves out of this state and toward a resolution of the current problems and into a beneficial situation. Thus an effective rhetoric critiques the current situation and offers a Utopian vision of where the society needs to go. It is this combination of threats and opportunities – nightmares combined with dreams – that fuels social movement mobilization and social change (Griffin 1966: 461). Thus what is needed is a new social vision that engages citizens and fosters the development of enlightened self-interest and an awareness of long-term community interests. The current state of ecological degradation brings such a project to the forefront of the challenge of human survival. While humans make their own history, we usually do this in a manner that is unconscious, and we unleash forces that produce destruction and human misery. This has now led the entire world to the brink of ecological catastrophe. To prevent this from becoming a reality, we need to intentionally foster the reflexive capacity of global society to increase its social learning and transformative capacity. A core component of this is the selfdetermination of human communities based on reasoned public deliberations. It is clear that to address environmental degradation, we need to be able to have a broad-based democratic discussion to establish universal and common goals. Thus civil society plays a critical role in developing the capacity to exercise effective guidance of our economic and administrative systems by democratic action.

References Alexander J (2006) The civil sphere. Oxford University Press, New York Bernstein S (2001) The compromise of liberal environmentalism. Columbia University Press, New York Brulle RJ (2000) Agency, democracy, and nature: the U.S. environmental movement from a critical theory perspective. MIT Press, Cambridge, MA

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Brulle RJ (2010) From environmental campaigns to advancing the public dialogue: environmental communication for civic engagement. Environ Comm J Nat Cult 4(1):82–98 Fischer J, Dyball R, Fazey I, Dovers S, Ehrlich PR, Gross C, Brulle RJ, Christensen C, Borden RJ (2012) Human behavior and sustainability. Front Ecol Environ 10(3):153–160 Griffin LM (1966) A dramatistic theory of the rhetoric of movements. In: Rueckert W (ed) Critical responses to Kenneth Burke, 1924–1966. University of Minnesota Press, Minneapolis, pp 456–478 Habermas J (1987) The theory of communicative action, volume two: lifeworld and system: a critique of functionalist reason. Beacon Press, Boston Habermas J (1989) The public sphere: an encyclopedia article. In: Bronner E, Kellner D (eds) Critical theory and society. Routledge, New York, pp 102–107 National Research Council (NRC) (1996) Understanding risk: informing decisions in a democratic society. National Academy Press, Washington, DC Rochon T (1998) Culture moves. Princeton University Press, Princeton York R, Rosa E, Dietz T (2003) Footprints on the earth: the environmental consequences of modernity. Am Sociol Rev 68(2):279–300

Index

A Ablation, 206, 207 Abrupt climate transitions, 52, 53 Abrupt ecosystem shift, 146–149 Absorption, 24, 26–28 Abundance, 176–179 Access to food, 709–715 Accumulation, 206, 207 Acidification, 154–155, 281–286 Actual yield, 381–383 Adaptation, 165, 350–354, 360, 502–503, 507, 594, 607–609, 612, 626, 651–653, 686, 687, 760, 762, 763, 765, 766, 768 Adaptation strategies, 730 Adaptive potential, 345 Aerosol(s), 23–29, 417–420, 422, 760, 766–768, 778–782 Agenda 21, 527–530 Agriculture, 392–394, 397, 630, 633, 635–640, 643 Agroecology, 726, 727, 733–742 Agroforestry, 738–739 Air pollution, 40, 42–44, 418, 419, 422, 459, 463, 659–662 Air quality modelling, 435–444 Air temperature, 448, 449, 451 Albedo, planetary, 771–775 Anoxia, 113, 114 Antarctic, 100, 168 Anthropocene, 599, 600 Anthropogenic CO2, 62, 65, 66, 104, 106, 108, 109 Anthropogenic forcing, 99, 100 Anthropogenic warming, 195 Aragonite, 152, 154, 155 Arctic, 98–101, 168 permafrost, 759 sea-ice, 760

Atmospheric pollutants, 469–478 Attainable yield, 381, 384

B Basic needs, 844–846 Biochar, 404 Biodiversity, 786, 789–790, 793, 798 Bio-energy, 390, 393–396 Biogeochemistry, 206, 335, 336, 350 Biogeographical shift, 143–146 Biological carbon pumps, 107–109, 125–131 Biomass, 784–786, 790–797 Biotic interactions, 345 Bleaching, 152–155, 157 Bond cycles, 57, 58 Brightening, 39–46 Buffer, 284 Building performance, 593–596 Buildings, damage, 455–460

C Calcification, 106–108 Calving, 207–209 Capability approach, 845, 847 Capacities and capabilities, 745–747 Capacity, 857–861 Carbon, 274, 279, 336–337, 339, 390–397 allocation, 297–314 cycle, 256, 257, 260, 758 emissions, 392, 393, 396 sequestration, 125–131, 370, 390, 399–409, 783–799 sinks, 759, 760 storage, 818, 819, 821–823 trading, 536 Carbon/CO2 tax, 544–551, 553–555, 557, 558

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968 Carbon dioxide, (CO2), 51, 125, 126, 255, 260, 283, 418, 422, 817–823 change, 64–65 concentrations of, 212 emission, 62, 64–66 mitigation, 562–565 sequestration, 783–798 sink, 66 valorization, 125–131, 565–569 Carbon dioxide removal (CDR) techniques, 758, 760, 763, 765 Carrying capacity, 573, 577 Cascading impacts, 408, 410, 411 Cetaceans, 168–172 Challenge messages, 963 Changing precipitation regimes, 301, 308–310 Citizenship, 869 Civil society, 959–965 Clean development mechanism, 518, 520–522, 524 Climate, 40, 44–46, 71–75, 425–433 change, 3–7, 16, 31–36, 78, 85–94, 105–109, 119, 120, 122, 133–138, 141–149, 161–165, 167–169, 175–179, 212, 231–240, 264, 267–270, 292–296, 350–354, 370, 375–377, 383, 385, 386, 408–413, 426, 430–432, 447–452, 518, 528–530, 534–535, 538–540, 593–596, 600–602, 615–620, 623–627, 629–647, 667–674, 695–699, 717–722, 758–766, 803–814, 926, 927 change mitigation, 389–397, 663, 785, 788 engineering, 773–774, 778, 780–782 envelope models, 358 impacts, 759, 762, 768 policy, 545, 547, 548, 553–558 problem, 761, 764–766, 768 science, 758, 766–769 sensitivity, 21 states, 766 variability, 80, 623 Climate-carbon feedbacks, 349–354 Climate–chemistry interaction, 425–433 Cloud brightening, 777–782 Clouds, 758, 760, 766, 768 Coasts, 160, 164 Co-benefits, 547, 556–558 Common pool resources, 882 Community composition, 359 Competition for land, 390, 396 Conservation, 357–359 practices, 407–413 tillage, 370

Index Contaminants, 617, 618 Coral reefs, 151–157 Corrosion, 458 Cost-benefit analysis (CBA), 926 Coupling of biogeochemical cycles, 339 Crop(s), 630, 634–646 harmful organisms, 381 loss, 381, 383–386 residue, 399 Cryosphere, 5–6 Cultural change, 830, 904, 943–950 Cultural evolution, 944, 947–950 Cultural rights, 913, 915, 916, 918–919, 922 Cyanobacteria, 273–279 Cyclones, 194

D Decadal climate variations, 40 Decentralization, 868–869 Decomposition, 400–404 Deforestation, 390, 392–394, 396 Deliberative democracy, 927 Democratic deliberation, 965 Demographic transition, 580 Demography, 360 Denitrification, 112–114, 330–333 Deoxygenation, 114 Desertification, 196, 369–377 Desmodium, 737 Direct and indirect effects on marine species, 182 Disaster management, 829 Disaster risk reduction, 610, 866–867 Distribution of marine fishes, 177–179 Distributional shifts, 344 Disturbance, 167 Domesticated species (mutualists), 574–575 Domestic policies, 523 Droughts, 32, 34–36, 606, 611, 633, 635, 638–640, 643, 645

E Earth radiation budget, 40 Earth system, 758, 762, 766 Ecological effects, 293, 294 Ecological footprint, 575–577 Ecological sequestration, 789 Ecological sustainability, 502–503 Economic growth, 585–991 Economic instruments, 878, 880–883 Economic sustainability, 503–505

Index Ecosystem engineers, 182 Ecosystem goods and services, 264–271 Ecosystem resilience and resistance, 133–138 Ecosystem services, 465 Elevated [CO2], 301, 306–309, 311, 313 El Nin˜o/Southern Oscillation (ENSO), 71, 73–75 Embodied experiences, 747, 751–752 Emerging, 617 Emerging infectious disease, 623–627 Emission target, 519 Emission trading, 520, 522 Energy effciency, 595, 596 Energy policy, 512, 515 Entitlements, 710, 711, 713, 715 Environment, 834, 835, 841, 846, 848–851 Environmental changes, 600, 602, 905 Environmental contaminants, 169–172 Environmental crisis, 586 Environmental effectiveness, 547, 548, 553 Environmental ethics, 829, 925–930 Environmental governance, 886, 887, 889, 890, 892–900 Environmental rights, 914–922 Equality, 934, 939 Equity, 933–939 Eutrophication, 273–279 Evaluation, 514–515 Evapotranspiration, 213–215 Externalities, 588 Extinction, 356, 357, 360 Extremes, 681–683, 686 Extreme weather events, 630, 638–643

F Faidherbia albida, 738 Fairness, 929 Famine, 365, 366, 631–635, 643–644, 646 Feedback loops, 944, 947–948 Feedbacks, 758, 759 Fertility rates, 580–583 Fertilization, 685–687 Fertilizing the ocean, 760 Fiscal incentives, 511, 512 Fish, 176–179 Fisheries, 168–170 Fisheries management, 176 Fishing, 176–179 Flexible mechanisms, 539 Floods, 32, 35, 36, 456, 457, 606, 608, 609, 611 Food, accessibility, 709–745

969 Food, availability, 681–688, 689–693, 695–699, 701–706 Food aid, 702, 703, 705, 706 Foodborne diseases, 615–620 Food exchange, 705 Food prices, 702–704 Food safety, 382–383, 385 Food security, 377, 379–386, 630, 634–639, 641, 645, 646, 667–674, 677–679, 690, 692–693, 696–699, 718 Food storage, 703, 705, 706 Food systems, 679 Food utilization, 717–722 Food waste, 644–645 Forcing agent, 19 Forecasting, 356 Forests, 390–396, 784–786, 788–796, 798 Fossil fuel emission, 64, 66 Freshwater biodiversity, 243–252 Freshwater ecosystems, 244–245, 251 Frost damage, 456 Future generations, 916, 919, 927, 930

G Gender, 719, 746–749, 751, 752 General circulation, 192 Geoengineering, 757–769, 772–775, 780, 804, 814 intervention, 761 methods, 760 research, 757–769 Glacier(s), 215 fluctuations, 206 mass balance, 207 retreat, 208 runoff, 206 Gliricidia, 738 Global Brightening, 39–46 Global change, 335–340, 379–386, 529–530, 599–603, 649–654 social aspects, 827–831 Global climate change, 1–7, 255–257 Global dimming, 39–46 Global environmental change, 678–679 Global environmental governance, 518 Globalization, 668–670 Global language loss, 904, 905 Global patterns of threat, 247–248 Global stressors, 135, 136, 138 Global warming, 183, 184, 218, 562 Global water cycle, 810 Governance frameworks, 829, 885–900

970 Grassland, 786, 788, 790–794, 796–798 Grazing systems, 692 Greenhouse effect, 23–29 Grassland, 786, 788, 790–794, 796–798 Greenhouse gas(es), 9–21, 195, 399–405, 418, 419, 422, 533–540, 561–569, 758–761, 763, 766 Greenhouse gas emissions, 543–558 Greenhouse gas offsets, 784 Green networks, 466 Green Paradox, 547, 550, 553–555 Green revolution, 632–634, 644, 646, 647

H Habitat connectivity, 466 Habitat-forming species, 182 Hadley cell, 192, 193 Health, 719–722 co-benefits of low carbon development pathways, 658, 659, 663 effects, 448, 452 Health impacts, 605–612, 615–620 Health risks, 649–655 Healthy bodies, 747 Heat effects, 449, 452 Heating mitigation, 490 Heat islands, 488–491 Heat temperature, 448, 449 Heat waves, 419, 447–452, 608, 611 Holocene climate, 55–59 Holocene thermal maximum, 56, 58 Human ecology, 506, 507 Human health, 418–420, 447–452, 599–603 Human impacts, 183 Human population, 572–575, 577 Human rights, 829, 844–846, 911–923 Human well-being, 264, 829, 833–851 Humus, 283 Hurricanes, 606 Hydroelectric development, 906 Hydrologic cycle, 32–34, 364, 366 Hydrology, 211–219 Hyogo framework for action, 867–869 Hypoxia, 114

I Ice cores, 50–53 Ice cover, 199–203, 218–219, 758 Impact, 689–693 Income, 835–837, 840, 843, 845, 847 Inequalities, 747–749, 751, 752

Index Infrastructures, 703–706 Intentional intervention in the climate, 762 Interactions, 184, 186 Interglacial, 55 Intergovernmental Panel on Climate Change (IPCC), 4 Intertropical Convergence Zone (ITCZ), 192–194 Invasive species, 463–464 Invertebrates, 176, 178, 179 Iron, 112

K Knowledge to adapt to climate change, 725–730, 951–957 Kyoto Protocol, 517–525, 535–539

L L1 Lagrange point, 805 Lake nutrients, 273–279 Lakes, 222, 223, 225–228, 231–240, 273–279 Land management, 389–397 Land-margin ecosystems, 159–165 Land use, 390, 392, 393, 395, 396 Land use change, 264, 270, 400, 403 Learning, 951–957 Learning bias, 944, 946 Limits to growth, 634–635, 646 Limnology, 232 Little ice age (LIA), 57, 58 Livestock, 689–693 Local stressors, 136

M Management, 682, 683, 685–687 Marine biodiversity, 181–187 Marine bioresources, 175–179 Marine carbon chemistry, 817 Marine fishes, distribution, 177–179 Marine mammals, 167–173 Marine species, direct and indirect effects, 182 Marine productivity, 176 Medieval climate anomaly, 58 Meltwater flux, 58 Meridional overturning circulation, 58 Metagovernance, 899–900 Methane, 256, 258–260, 418, 422, 426–430, 433, 759 Methane oxidation, 326 Methanogenesis, 328

Index Microbial ecology, 350 Migration flows, 581 Millennium Development Goals (MDGs), 365 Mitigation, 480, 594, 759, 760, 763–766, 768 Mitigation and adaptation strategies, 296 Mixed systems, 692 Modelling scenarios, 477 Monitoring, 649–654 Monsoon, 56–58 Moral hazard, 763 Mortality, 448–452 Multiple stressors, 182

N N2 fixation, 112–114 Natality rate, 581–582 National Commission on Energy policy, 760 Natural areas, 408, 410–413 Natural hazard, 858 Natural variability, 98 Neoglacial, 56–58 Neoliberalism, 669 Net primary production (NPP), 117–122, 298, 302 Niche, 358, 360 envelope models, 345 evolution, 343 Nitrification, 330, 331 Nitrogen, 112, 274, 275, 278, 279, 336, 338–339 Nitrogen deposition, 301, 305, 310–313 Nitrogen dioxide, 418, 420, 421 NO2 emission control measures, 475–478 Noise barriers, 482, 483 Noncommunicable diseases, 658 Non-grazing systems, 691, 692 Non-timber forest products, 695–699 Norms and standards, 513–515 No till, 399 Numerical downscaling, 438 Nutrient pollution, 136–138, 160, 163 Nutrients, 222, 226–227, 266–268, 270, 273–279 Nutrition, 630, 631, 639, 644–647, 718, 719, 722

O Ocean(s), 4–6, 817–823 acidification, 103–109, 165, 183–185, 811, 821 carbon cycling, 103–109

971 circulation, 50, 81, 86–88, 93 dynamics, 758 heat content, 77–82 primary production, 125 Orbital (Milankovitch) cycles, 50–52 Orbital forcing, 56 Organic acids, 286 Organic aerosol, 426, 428 Organic carbon, 281–286 Organic matter, 282–285, 784–786, 790–792, 797 Organo-mineral complex, 281 Otters, 169, 170 Overpopulation, 575, 577 Oxygen, 111–115 Ozone, dissolved, 111–115, 418–420, 422, 426–433, 436, 441 Ozone depletion, 775

P Paleoclimatology, 50 Paleolimnology, 232, 234, 240 Participation, 869 Particulate matter, 417–420, 422, 436, 438 Pathogens, 172 Pelagic ecosystems, 141–149 Perennial crops, 739–740 Phenological shift, 143–144 Phosphorus, 112, 273–279, 336 Photosynthesis, 118, 152, 153, 682–686 Physical carbon pump, 105–109 Phytoplankton, 118, 119, 121, 122, 126, 128–130 Pinnipeds, 169–171 Plant community composition, 341–346 Plant growth, 681–687 Plant protection, 384, 386 PM10, 420, 435–445, 470–477 Polar bears, 168, 170 Polluter pays, 926 Pollution, 528–530, 873–883 Pollution control, 830, 873–883 Ponds, 222, 223, 227, 228 Population control, 580–583 Population growth, 571–577, 670 Population policies, 579–583 Porter Hypothesis, 551, 552 Positive feedback, 317–319 Potential yield, 381 Poverty, 633 Precipitation, 31, 32, 34–36, 191–197, 213–215

972 Prediction, 360 Primary production, 106, 108, 222, 225–227 Primary productivity, 118, 120 Production levels, 380, 381 Production situation, 385, 386 Public engagement, 764 Public goods, 877 Public health prevention, 650 Public policy, 510 Public sphere, 962 Push-pull technology, 736–737

R Radiation, 765, 766 Radiative forcing, 9–21, 24, 26–29 Rainfall, 31, 32, 35 Range-shifts, 184 Reflective aerosols, 23–29 Refractive index, 27 Regional climate change, 436 Resilience, 501–504, 715 Resource depletion, 671–672, 674 Resources, 681 Respiration, 320 Revenue recycling, 545 Richness and vulnerability, 244–245 Risk, 858–861 Rivers, 222, 223, 228, 263–271

S Salinity, 222, 227 Salt weathering, 458 Saturation state, 106 Scarcity, 244–245 Scattering, 24, 26, 27 Sea ice area, 97–101 Sea ice extent, 98–100 Sea level, 78, 79, 82, 206, 208, 209 change, 50, 53 rise, 5–7, 160, 163–164 Sea salt, 779–782 Sea-surface temperature (SST), 71–75 Seawater, 819–822 Seawater acidity, 103 Secondary production, 222, 226, 227 Silicate, 111 Single-scattering albedo (SSA), 27 Sirenians, 170

Index Snow, 758 Snow cover, 216 Social aspects, global change, 827–831 Social capital, 728, 729 Social indicators, 847–849 Social inequalities, 588–589 Social learning, 944, 953–954, 957, 965 Social movements, 960–962, 965 Social sustainability, 505–508 Societal change, 951–957 Socioeconomic capability, 745–752 Socioeconomic implications, 293, 295 Socioeconomic inequality, 934–938 Soil, 350–353 erosion, 369–377 fertility management, 733 greenhouse gas emission, 325–333 management, 400, 403 organic matter, 317–321, 400, 402, 403, 405 quality, 371–372 trace gas emissions, 325–333 Solar energy, 44 Solar radiation management (SRM), 758, 760–766, 775, 778–781, 804–806, 808–811, 813, 814 geoengineering, 762, 764 technologies, 762 Southern Ocean, 98, 100, 101 Space sunshades, 803–814 Species distributions, 358–361 Species translocations, 361 Stratification, 222, 227 Stratospheric aerosol, 772, 774, 775 Streams, 222, 225, 226, 228, 264–271 Sub-Saharan Africa, 726, 729 Subsidies, 512–514 Suffering, 760, 764–766 Sulfate aerosols, 428, 430, 432, 433 Surveillance, 649–654 Sustainability, 933–939, 943–957 Sustainable agriculture, 726 Sustainable development, 422, 499–508, 528, 530, 591, 848–850 Synanthropic species, 574–575, 577 Synergistic effects, 134 Systemic hazards, 600 Systems analysis, 380

Index T Temperature, 78–81, 222, 224–228, 264, 268, 269 Temperature sensitivity, 320, 321 Termination problem, 765 Terrestrial biodiversity, 355–361 Terrestrial ecosystem distribution, 341–346 Terrestrial ecosystems, 291–296, 335–346 Terrestrial plant productivity, 297–314 Thermal comfort, 595, 596 Threat factors, 246–247, 250 Threat messages, 963 Tipping point, 768 Toxins, 382 Tradable permits, 533–540 Transgovernance, 899–900 Trophic cascade, 178 Trophic state, 273

U Uncertainty, 356, 358, 360, 361 United Nations, 530 Urban, 417–422 air quality, 481 atmospheres, 417–422, 425–433 biodiversity, 461–467 climate, 455–460 design, 484 heat, 418, 419, 422 heat island effect, 462–463, 466 planning, 465–466 pollution, 491 vegetation, 487–493 Utility, 835–843, 845

973 V Vector-borne disease, 623–627 Vegetation, 399–405, 479–484 Voluntary agreements, 511, 512, 514 Vulnerability, 710, 713, 714, 719, 722, 829, 857–861

W Warming, 299, 301–303, 305, 307–311, 313 Water, 629–647 cycles, 31–37 deficit, 363–367 quality, 463 shortage, 364 vapor, 32, 34–36 Waterborne diseases, 615–620 Watersheds, 264, 271 Weather and climate extremes, 605–612, 651 Well-being, 833–850 Well-being indicators, 589–591 Wetlands, 222, 223, 227, 228, 255–260, 786, 791, 792, 797–798 Wetlands ecosystems, 255–260 Wild foods, 696–699 Wind driven rain, 456, 459 World economy, 588

Y Yield loss, 381, 384

Z Zooxanthellae, 152–154, 157