Climate Change Adaptation Plan City of Johannesburg Acknowledgements The following people contributed to the development of the Climate Change Adaptation Plan : Linda Phalatse and Mzukisi Gwata (City of Johannesburg) for their roles as Project Managers, Elan Theeboom (WSP Environment & Energy) for his Project Management role and preparations for this report, Dr Peter Johnston (UCT Climate Systems Analysis Group) for his key role within the project team and for his contribution to the risk assessment and adaptation planning process across all sectors but with particular focus on Community Development and Livelihood issues; Manfred Braune (WSP Green by Design) likewise for his key role and contribution to the risk assessment and adaptation planning process across all sectors but with particular focus on Infrastructural and Urban Planning issues; and Prof. Bruce Hewitson and Lisa Coop (UCT Climate Systems Analysis Group) for their work on the downscaling of climate model projections for the CoJ region. This assessment has relied on the input of a large number of technical experts across a wide range of environmental and engineering sectors. The authors would like to specifically acknowledge Kobus de Villiers (WSP Consulting Engineers) for his energy-demand modelling for air-conditioning and refrigeration, and Kevin van Blerk (WSP Civil & Structural) for his input on stormwater modelling. The authors would also like to thank the members of the CoJ Johannesburg Climate Change Coordination Committee (JCCCC) and all other CoJ staff members and consultants who took part in the various workshops for their invaluable input and feedback. Contact It is likely that this document is updated and improved over time. Should you have any suggestions please email suggestions to Linda Phalatse at [email protected] Disclaimer The views and opinions expressed in this publication are those of the authors and do not necessarily reflect those of the City of Joburg. While reasonable efforts have been made to ensure that the contents of this guide are factually correct, the City of Joburg does not accept responsibility for the accuracy or completeness of the contents, and shall not be liable for any loss or damage that may result, directly, or indirectly, through the use of, or reliance on, the contents of this publication. © City of Joburg, 2009 This work is copyright and no part may be reproduced without written permission. Permission for reproduction should be directed to the City of Joburg. Table of Contents 1. INTRODUCTION 1 1.1 Background 1 1.2 Policy Framework 1 1.3 Mitigation versus Adaptation 2 1.4 Comparative Vulnerability of the CoJ 3 2. METHODOLOGY 4 2.1 Risk Assessment Methodology 4 2.2 Climate Modelling Methodology 5 3. CLIMATE CHANGE AND THE COJ 6 3.1 Geography of the CoJ 6 3.2 Current Climate 7 3.3 Temperature 8 3.3.1 Current Trends in Temperature 8 3.3.2 Future Trends in Temperature 9 3.3.3 Extreme Temperature 10 3.4 Precipitation 15 3.4.1 Current Trends in Precipitation 15 3.4.2 Future Trends in Precipitation 16 3.4.3 Extreme Precipitation 18 3.5 Other Climatic Variables 22 3.5.1 Evapotranspiration 22 3.5.2 Humidity 22 3.5.3 High Pressure Cell 22 3.5.4 Wind, Hail, Lightning and other Weather-related Events 22 4. VULNERABILITIES OF COJ KEY SECTORS 24 4.1 Introduction 24 4.2 Environment 24 4.2.1 Introduction 24 4.2.2 Air Quality 24 4.2.3 Natural Water Resources 25 4.2.4 Biodiversity 26 4.3 Health 27 4.4 Infrastructure 27 4.4.1 Stormwater 27 4.4.2 Water Supply & Sanitation 29 4.4.3 Transport 30 4.4.4 Energy, Electrical and Telecommunications 30 4.4.5 Built and Urban Environment 32 4.5 Disaster Management 33 4.6 Finance & Economy 33 4.7 Community Development & Livelihood 34 4.7.1 Climate Change and Urban Poverty 34 4.7.2 Employment 35 4.7.3 Housing and Living Environment 35 4.7.4 Food Security 36 4.7.5 Water Security 37 4.7.6 Migration 38 5. RISK ASSESSMENT 40 5.1 Introduction 40 5.2 Risk Assessment Framework 40 5.2.1 Risk Identification 40 5.2.2 Risk Prioritising 40 5.3 Risks due to Changes in Temperature 42 5.4 Risks Due to Changes in Precipitation 45 5.5 Risks Arising from Climate Change Impacts outside the CoJ Boundaries 48 5.6 Risks Due to Changes in Other Synoptic & Climatic Variables 50 5.7 Summary 52 6. KEY FINDINGS - HIGH PRIORITY RISKS 53 6.1 Introduction 53 6.2 Risk T1: Increase in Heat-Related Death 53 6.3 Risk T2: Increase in Energy Demand 56 6.4 Risk TP4: Biodiversity Impacts on Disease Vectors - Health Risks 58 6.5 Risks P1 - P4: Increased Risk of Urban Flooding 60 6.6 Risks X1 & T3: Disruption to Water Security 65 6.7 Risk X2: Climate Change-driven Refugees and Migrants 68 7. ADAPTATION ACTIONS FOR CoJ 69 7.1 Introduction 69 7.2 The Cost of Adaptations 70 7.2.1 Introduction 70 7.2.2 Methodology 71 7.2.3 Future Assessment of Costs and Benefits 71 7.3 Adaptations for High Priority Risks 72 7.3.1 Risk T1: Increase in Heat-Related Death 72 7.3.2 Risk T2: Increase in Energy Demand 73 7.3.3 Risk TP4: Biodiversity Impacts on Disease Vectors - Health Risks 74 7.3.4 Risks P1 - P4: Increased Risk of Urban Flooding 75 7.3.5 Risks X1 & T3: Disruption to Water Security 78 7.3.6 Risk X2: Climate Change-driven Refugees and Migrants 80 7.4 Strategic Adaptations 81 7.5 Summary of Key Adaptations 84 LIST OF FIGURES Figure 1: Decision-Making Framework (UKCIP, 2003)……………………………………………………………………4 Figure 3: Map showing the administrative regions of the City of Johannesburg ........................................................... 7 Figure 4: Time series of downscaled mean annual daily maximum surface temperature (°C) ......................................11 Figure 5: Mean seasonal cycle of downscaled daily maximum temperature (°C) ........................................................12 Figure 6: Time series of downscaled mean annual daily minimum surface temperature (°C) ........................................13 Figure 7: Mean seasonal cycle of downscaled maximum temperature (°C) .................................................................14 Figure 8: Time series of downscaled mean annual daily precipitation (mm) .............................................................. 20 Figure 9: Mean seasonal cycle of downscaled monthly total precipitation (mm) ..........................................................21 Figure 10: Surface specific humidity simulated by the Meteo-France/CNRM GCM .....................................................23 Figure 11: Weather Fatalities in the U.S ...............................................................................................................54 LIST OF TABLES Table 1: Climate Data for the CoJ for the period 1961 - 1990 ..................................................................................... 8 Table 2: Trends in Temperatures 1961-2006 (Krugersdorp weather station) .............................................................. 9 Table 3: Increase in Average Maximum Day-Time Temperature1 ...............................................................................................................................................................9 Table 4: Increase in Average Minimum Night-Time Temperature1 ...........................................................................................................................................................10 Table 5: Frequency of Temperature Thresholds Exceeded (days/month) ...................................................................15 Table 6: Trends in Precipitation 1961-2006. (Krugersdorp weather station) .............................................................. 15 Table 7: Change in Precipitation Projections (mm/month) for the CoJ .........................................................................17 Table 8: Possible Mean Seasonal Increases (%) in Rainfall for the CoJ ......................................................................17 Table 9: Mean Precipitation: historic and potential future rainfall figures ....................................................................17 Table 10: No. of Rain-days in the CoJ: Control Period vs. Future Periods ................................................................ 18 Table 11: No. of Rain-days in the CoJ: Control Period vs. Future Periods ................................................................ 19 Table 12: Relative contribution of different sectors to the CoJ economy for 2000 & 2007 .............................................33 Table 13: Risks due to predicted changes in temperatures within the CoJ region .......................................................42 Table 14: Risks due to predicted changes in precipitation within the CoJ region .........................................................45 Table 15: Risks due to climate change impacts outside of the CoJ region ................................................................ 48 Table 16: Risks due to predicted changes in other synoptic/climatic variables ........................................................... 50 Table 17: Strategic Adaptations for the CoJ and Preliminary Cost/Value Rankings1 .........................................................................................................86 Table 18: Key Adaptations for the CoJ and Draft Preliminary Cost/Value Rankings1 .......................................................................................................88 LIST OF APPENDICES Appendix A: Glossary Appendix B: SRES Scenarios EXECUTIVE SUMMARY There is broad international consensus that some Risk X2: Climate-Change-driven Refugees and degree