NSW Climate Impact Profile
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NSW Climate Impact Profile The impacts of climate change on the biophysical environment of New South Wales Cover photos (main image, clockwise): Aerial view of Lane Cove River (Andrew Duffy); Helensburgh fires (Allan House); Redhead Bluff (Brook Lesley); White-bellied sea eagle (Joel Winter). © Copyright State of NSW and Department of Environment, Climate Change and Water NSW. The Department of Environment and Climate Change NSW and State of NSW are pleased to allow this material to be reproduced for educational or non-commercial purposes in whole or in part, provided the meaning is unchanged and its source, publisher and authorship are acknowledged. Specific permission is required for the reproduction of photographs and images. Published by: Department of Environment, Climate Change and Water NSW 59–61 Goulburn Street PO Box A290 Sydney South 1232 Ph: (02) 9995 5000 (switchboard) Ph: 131 555 (environment information and publications requests) Ph: 1300 361 967 (national parks information and publications requests) Fax: (02) 9995 5999 TTY: (02) 9211 4723 Email: [email protected] Website: www.environment.nsw.gov.au ISBN 978 1 74232 259 9 DECCW 2010/171 June 2010 Printed on recycled paper NSW Climate Impact Profile The impacts of climate change on the biophysical environment of New South Wales Director General’s foreword Climate change is one of the most serious challenges we face. It has the potential to affect all aspects of our lives and the environment we live in. While many impacts may not be felt for decades, we need to start planning for climate change now to ensure we can cope with any future changes. The decisions we make today will have lasting consequences. The Department of Environment, Climate Change and Water NSW (DECCW), with assistance from the University of New South Wales, has developed the NSW Climate Impact Profile to help government, business and the community plan for the future. The report describes some of the likely changes to our climate and the implications of these changes for our natural ecosystems, the lands we manage, and our towns and cities. New South Wales has a very diverse climate, and future changes in temperature, rainfall and evaporation will affect each part of the state differently. The NSW Climate Impact Profile takes account of these regional differences by presenting information on the likely impacts of climate change in each of the State Plan regions. A better understanding of the local and regional impacts of climate change will help communities to develop responses that suit local conditions. The NSW Government is committed to establishing a sound scientific basis for understanding climate change in NSW and developing adaptation responses. This document is only a first step in understanding some of the changes we may face in the future. As new science emerges, the NSW Government will continue to support research to ensure that NSW has access to the best-available information on future climate change. Lisa Corbyn Director General iii Contents Director General’s foreword iii List of tables and figures vi Abbreviations ix Executive summary x 1 Introduction 1 1.1 Our climate is changing 1 1.2 Climate change will affect our environment and communities 2 1.3 Regional information is needed to guide planning and decision making 3 1.4 How to use this report 4 2 Assessment approach 5 2.1 Developing regional climate projections for NSW 5 The need for better information on future climate changes 5 Developing refined regional climate projections 7 How does this data differ from other climate change projections? 7 Limitations of current projections 9 2.2 Developing sea level rise projections for NSW 10 The link between sea level rise and global warming 10 IPCC’s sea level rise projections for 2050 and 2100 10 Observations of global sea level rise 11 Localised variations in sea level 12 Summary of contributions to sea level rise 12 2.3 Assessing the biophysical impacts of climate change in NSW 13 Biodiversity 14 Soils and land degradation 15 Stream flow and run-off 15 Coastal zone 16 Flooding risk 16 2.4 Assessment limitations 17 3 Climate change in NSW 18 3.1 Past climate change 18 3.2 The current NSW climate 20 3.3 Future climate change in NSW 25 Changes in maximum and minimum temperatures 26 Changes in average and seasonal rainfall 26 Changes in evaporation 31 4 Impacts of climate change in NSW 32 4.1 Expected physical responses 34 4.2 Impacts on land 35 4.3 Impacts on settlements 36 4.4 Impacts on ecosystems 37 iv 5 Regional impacts of climate change 40 5.1 The Hunter region 40 Characteristics of the region 41 Expected regional climatic changes 42 Expected physical responses 44 Regionally significant impacts 47 5.2 The Illawarra region 54 Characteristics of the region 55 Expected regional climatic changes 56 Expected physical responses 58 Regionally significant impacts 60 5.3 The North Coast region 65 Characteristics of the region 65 Expected regional climatic changes 67 Expected physical responses 68 Regionally significant impacts 71 5.4 The New England/North West region 78 Characteristics of the region 78 Expected regional climatic changes 79 Expected physical responses 82 Regionally significant impacts 85 5.5 The Riverina Murray region 90 Characteristics of the region 90 Expected regional climatic changes 91 Expected physical responses 93 Regionally significant impacts 96 5.6 The Western region 102 Characteristics of the region 102 Expected regional climatic changes 104 Expected physical responses 106 Regionally significant impacts 109 5.7 The South East region 115 Characteristics of the region 115 Expected regional climatic changes 117 Expected physical responses 119 Regionally significant impacts 122 5.8 The Sydney/Central Coast region 130 Characteristics of the region 130 Expected regional climatic changes 132 Expected physical responses 134 Regionally significant impacts 137 References 144 Glossary 147 Appendix A: Assessment of hydrological impacts 149 v List of tables and figures Figure 2.1: Annual averages of the global mean sea level (cm) (UNEP/GRID-Arendal 2007a) 11 Figure 2.2: Projected sea level rise for the twenty-first century (UNEP/GRID-Arendal 2007b) 12 Figure 2.3: NSW State Plan regions (NSW Government 2006) 14 Figure 3.1: Global annual mean temperature anomalies, 1850–2007 18 Figure 3.2: Annual mean temperature anomalies for Australia, 1910–2007 19 Figure 3.3: Annual mean temperature anomalies for NSW, 1910–2007 19 Figure 3.4: Major seasonal rainfall zones of Australia (BOM 2008d) 21 Figure 3.5: Annual rainfall for the southern Blue Mountains over a 106-year period from 1900–2006 (adapted from BOM 2008d) 24 Figure 3.6: Projected increases in seasonal average maximum temperatures by 2050 27 Figure 3.7: Projected increases in seasonal average minimum temperatures by 2050 28 Figure 3.8: Projected changes in rainfall to 2050, in spring, summer, autumn and winter 29 Figure 3.9: Projected average changes in rainfall to 2050 30 Figure 3.10: Historical rainfall variability compared with 2050 projections for the south-western Riverina 30 Figure 5.1: Estimated four-model mean percentage change in seasonal run-off for the Hunter region for projected 2030 climatic conditions 45 Figure 5.2: Estimated four-model mean percentage change in seasonal run-off for the Illawarra region for projected 2030 climatic conditions 58 Figure 5.3: Estimated four-model mean percentage change in seasonal run-off for the North Coast region for projected 2030 climatic conditions 69 Figure 5.4: Estimated four-model mean percentage change in seasonal run-off for the New England/North West region for projected 2030 climatic conditions 82 Figure 5.5: Estimated four-model mean percentage change in seasonal run-off for the Riverina Murray region for projected 2030 climatic conditions 94 Figure 5.6: Estimated four-model mean percentage change in seasonal run-off for the Western region for projected 2030 climatic conditions 107 Figure 5.7: Estimated four-model mean percentage change in seasonal run-off for the South East region for projected 2030 climatic conditions 120 Figure 5.8: Estimated four-model mean percentage change in seasonal run-off for the Sydney and Central Coast subregions for projected 2030 climatic conditions 134 vi Table 2.1: Projected temperature change and sea level rise (due to thermal expansion only) for the six IPCC emissions scenarios 10 Table 2.2: Summary of components contributing to future projections of sea level rise in NSW 13 Table 3.1: Types of climate data modelled for this project 25 Table 5.1: Modelled changes in run-off in the Hunter region 46 Table 5.2: Modelled changes in run-off in the Illawarra region 59 Table 5.3: Modelled changes in run-off in the North Coast region 70 Table 5.4: Modelled changes in run-off in the New England/North West region 84 Table 5.5: Modelled changes in run-off in the Riverina Murray region 95 Table 5.6: Modelled changes in run-off in the Western region 108 Table 5.7: Modelled changes in run-off in the South East region 121 Table 5.8: Modelled changes in run-off in the Sydney/Central Coast region 136 Box 2.1: IPCC emissions scenarios 6 Box 2.2: Evaluating the performance of global climate models (GCMs) 8 Box 3.1: Climate change and variability from a long-term perspective 20 Box 3.2: Major climate influences for Australia and NSW (BOM 2008e) 22 Box 3.3: Climate variability in the southern Blue Mountains 24 Box 4.1: Terminology for probability of occurrence and magnitude of impacts 32 Box 5.1: Examples of areas vulnerable to flooding