Turn Down the Heat: Climate Extremes, Regional Impacts, and the Case for Resilience
Total Page：16
File Type：pdf, Size：1020Kb
Turn Down the Climate Extremes, Regional Impacts, Heatand the Case for Resilience June 2013 A Report for the World Bank by the Potsdam Institute for Climate Impact Research and Climate Analytics © 2013 International Bank for Reconstruction and Development / The World Bank 1818 H Street NW, Washington DC 20433 Telephone: 202-473-1000; Internet: www.worldbank.org Some rights reserved 1 2 3 4 16 15 14 13 This report was prepared for the World Bank by the Potsdam Institute for Climate Impact Research and Climate Analytics. Note that The World Bank does not necessarily own each component of the content included in the commissioned work. The World Bank therefore does not warrant that the use of the content contained in the work will not infringe on the rights of third parties. The risk of claims resulting from such infringement rests solely with you. The findings, interpretations, and conclusions expressed in this work do not necessarily reflect the views of The World Bank, its Board of Executive Directors, or the governments they represent. The World Bank does not guarantee the accuracy of the data included in this commissioned work. The boundaries, colors, denominations, and other information shown on any map in this work do not imply any judgment on the part of The World Bank concerning the legal status of any territory or the endorsement or acceptance of such boundaries. Nothing herein shall constitute or be considered to be a limitation upon or waiver of the privileges and immunities of The World Bank, all of which are specifically reserved. Rights and Permissions This work is available under the Creative Commons Attribution—NonCommercial–NoDerivatives3.0 Unported license (CC BY-NC-ND 3.0) http://creativecommons.org/licenses/by-nc-nd/3.0. Under the Creative Commons Attribution—NonCommercial–NoDerivatives license, you are free to copy, distribute, and transmit this work, for noncommercial purposes only, under the following conditions: Attribution—Please cite the work as follows: World Bank. 2013. Turn Down the Heat: Climate Extremes, Regional Impacts, and the Case for Resilience. A report for the World Bank by the Potsdam Institute for Climate Impact Research and Climate Analytics. Washington, DC:World Bank. License: Creative Commons Attribution—NonCommercial–NoDerivatives3.0 Unported license (CC BY-NC-ND 3.0). Noncommercial—You may not use this work for commercial purposes. No Derivative Works—You may not alter, transform, or build upon this work. All queries on rights and licenses should be addressed to the Office of the Publisher, The World Bank, 1818 H Street NW, Washington, DC 20433, USA; fax: 202-522-2625; e-mail: [email protected]. Please note that the items listed below require further permission for reuse. Please refer to the caption or note corresponding to each item. Figures 3, 3.12, 3.13, 3.14, 3.15, 3.16, 3.17, 3.18, 4.9, 4.11, 5.9, 5.11, 5.12, 6.4, 6.9, 6.12, and Tables 4.2, 4.6. ISBN (electronic): 978-1-4648-0056-6 Cover photos: The World Bank and istockphoto (tree rings); Cover design: Gregory Wlosinski, General Services Department—Printing and Multimedia, The World Bank. Contents Acknowledgments ix Foreword xi Executive Summary xv Abbreviations xxxi Glossary xxxiii 1. Introduction 1 2. The Global Picture 7 How Likely is a 4°C World? 8 Patterns of Climate Change 9 Sea-level Rise 14 3. Sub-Saharan Africa: Food Production at Risk 19 Regional Summary 19 Introduction 24 Regional Patterns of Climate Change 25 Regional Sea-level Rise 32 Water Availability 34 Agricultural Production 37 Projected Ecosystem Changes 49 Human Impacts 52 Conclusion 56 4. South East Asia: Coastal Zones and Productivity at Risk 65 Regional Summary 65 Introduction 70 Regional Patterns of Climate Change 70 Tropical Cyclone Risks 74 Regional Sea-level Rise 76 Risks to Rural Livelihoods in Deltaic and Coastal Regions 77 Risks to Coastal Cities 82 Coastal and Marine Ecosystems 86 iii TURN DOWN THE HEAT: CLIMATE EXTREMES, REGIONAL IMPACTS, AND THE CASE FOR RESILIENCE Projected Impacts on Economic and Human Development 92 Conclusion 95 5. South Asia: Extremes of Water Scarcity and Excess 105 Regional Summary 105 Introduction 110 Regional Patterns of Climate Change 110 Regional Sea-level Rise 117 Water Resources 118 Cities and Regions at Risk of Flooding 122 Agricultural Production 125 Human Impacts 135 Conclusion 138 6. Global Projections of Sectoral and Inter-sectoral Impacts and Risks 149 Multisectoral Exposure Hotspots for Climate Projections from ISI-MIP Models 149 Water Availability 150 Risk of Terrestrial Ecosystem Shifts 153 Crop Production and Sector Interactions 155 Regions Vulnerable to Multisector Pressures 156 Non-linear and Cascading Impacts 161 Appendix 1. Background Material on the Likelihood of a 4°C and a 2°C World 167 Appendix 2. Methods for Temperature, Precipitation, Heat Wave, and Aridity Projections 173 Appendix 3. Methods for Multisectoral Hotspots Analysis 181 Appendix 4. Crop Yield Changes under Climate Change 185 Bibliography 191 Figures 1.1 Projected sea-level rise and northern-hemisphere summer heat events over land in a 2°C World (upper panel) and a 4°C World (lower panel) 3 2.1 Time series from the instrumental measurement record of global-mean annual-mean surface-air temperature anomalies relative to a 1851–80 reference period 8 2.2 Global-mean surface-air temperature time series unadjusted and adjusted for short-term variability 8 2.3 Sea-level rise from observations and models 9 2.4 Projections for surface-air temperature increase 10 2.5 Temperature projections for global land area 10 2.6 Multi-model mean temperature anomaly for RCP2.6 (left) and RCP8.5 (right) for the months of JJA 11 2.7 Multi-model mean and individual models of the percentage of global land area warmer than 3-sigma (top) and 5-sigma (bottom) during boreal summer months (JJA) for scenarios RCP2.6 and RCP8.5 13 2.8 Multi-model mean of the percentage change in annual mean precipitation for RCP2.6 (left) and RCP8.5 (right) by 2071–99 relative to 1951–80 14 2.9 Projections of the rate of global sea-level rise (left panel) and global sea-level rise (right panel) 15 2.10 Sea-level rise in the period 2081–2100 relative to 1986–2005 for the high-emission scenario RCP8.5 15 2.11 Sea-level rise in the period 2081–2100 relative to 1986–2005 along the world’s coastlines, from south to north 16 iv CONTENTS 3.1 Sub Sahara Africa – Multi-model mean of the percentage change in the Aridity Index In a 2°C world (left) and a 4°C world (right) for Sub-Saharan Africa by 2071–2099 relative to 1951–1980 21 3.2 Temperature projections for Sub-Saharan land area 26 3.3 Multi-model mean temperature anomaly for RCP2.6 (left) and RCP8.5 (right) for the months of DJF for Sub-Saharan Africa 26 3.4 Multi-model mean of the percentage of austral summer months in the time period 2071–99 27 3.5 Multi-model mean (thick line) and individual models (thin lines) of the percentage of Sub-Saharan African land area warmer than 3-sigma (top) and 5-sigma (bottom) during austral summer months (DJF) for scenarios RCP2.6 and RCP8.5 28 3.6 Multi-model mean of the percentage change in annual (top), austral summer (DJF-middle) and austral winter (JJA-bottom) precipitation for RCP2.6 (left) and RCP8.5 (right) for Sub-Saharan Africa by 2071–99 relative to 1951–80 29 3.7 Multi-model mean of the percentage change in the annual-mean of monthly potential evapotranspiration for RCP2.6 (left) and RCP8.5 (right) for Sub-Saharan Africa by 2071–99 relative to 1951–80 31 3.8 Multi-model mean of the percentage change in the aridity index in a 2°C world (left) and a 4°C world (right) for Sub-Saharan Africa by 2071–99 relative to 1951–80 31 3.9 Multi-model mean (thick line) and individual models (thin lines) of the percentage of Sub-Saharan African land area under sub-humid, semi-arid, arid, and hyper-arid conditions for scenarios RCP2.6 (left) and RCP8.5 (right) 32 3.10 Regional sea-level rise in 2081–2100 (relative to 1986–2005) for the Sub-Saharan coastline under RCP8.5 32 3.11 Local sea-level rise above 1986–2005 mean as a result of global climate change 33 3.12 Crop land in Sub-Saharan Africa in year 2000 37 3.13 Average “yield gap” (difference between potential and achieved yields) for maize, wheat, and rice for the year 2000 38 3.14 Climate change impacts on African agriculture as projected in recent literature after approval and publication of the IPCC Fourth Assessment Report (AR4) 40 3.15 Mean crop yield changes (percent) in 2070–2099 compared to 1971–2000 with corresponding standard deviations (percent) in six single cropping systems (upper panel) and thirteen sequential cropping systems (lower panel) 43 3.16 Percentage overlap between the current (1993–2002 average) distribution of growing season temperatures as recorded within a country and the simulated 2050 distribution of temperatures in the same country 44 3.17 Observed cattle density in year 2000 47 3.18 Projections of transitions from C4-dominated vegetation cover to C3-dominated vegetation for SRES A1B, in which GMT increases by 2.8°C above 1980–99 50 4.1 South East Asia – The regional pattern of sea-level rise in a 4°C world (left; RCP8.5) as projected by using the semi-empirical approach adopted in this report and time-series of projected sea-level rise for two selected cities in the region (right) for both RCP2.6 (2ºC world) and RCP8.5 (4°C world) 67 4.2 Temperature projections for South East Asian land area, for the multi-model mean (thick line) and individual models (thin lines) under RCP2.6 and RCP8.5 for the months of JJA