TECHNICAL REPORT PROJECTIONS FOR AUSTRALIA´S NRM REGIONS MACDONNELL RANGES, NORTHERN TERRITORY, ISTOCK TECHNICAL REPORT PROJECTIONS FOR AUSTRALIA´S NRM REGIONS D CLIMATE CHANGE IN AUSTRALIA © CSIRO 2015 7.7 Freddie Mpelasoka, Francis Chiew, Ian Watterson, Jonas Bhend and Louise Wilson CLIMATE CHANGE IN AUSTRALIA 7.8 Chris Lucas TECHNICAL REPORT CHAPTER 8 BIBLIOGRAPHY Kathy McInnes, Didier Monselesan, John Church, ISBN 9781921232947 (PDF) Andrew Lenton and Julian O’Grady CONTACTS CHAPTER 9 E: [email protected] Kevin Hennessy, Leanne Webb and John Clarke T: 1300 363 400 CHAPTER 10 Paul Holper and Penny Whetton ACKNOWLEDGEMENTS APPENDIX A This scientifi c assessment and new research has been Ian Watterson funded by the Australian Government Department of the Environment, the Commonwealth Scientifi c and Industrial PROJECTIONS ANALYSIS SUPPORT Research Organisation and the Australian Bureau of Janice Bathols, Tim Bedin, Tim Erwin, Craig Heady, Yun Li Meteorology. The work has benefi ted from a high degree and Louise Wilson of cooperation between these agencies and the project stakeholders. PROJECT COORDINATION LEAD SCIENTIST AND EDITOR Paul Holper, Kevin Hennessy, Carol Grossman and Mandy Hopkins Penny Whetton PEER REVIEW EDITORS David Karoly (University of Melbourne), Andrew Tait Marie Ekström, Chris Gerbing, Michael Grose, Jonas Bhend, (National Institute of Water and Atmospheric Research, Leanne Webb and James Risbey. New Zealand) and Michael Hutchinson (Australian National CHAPTER AUTHORS University) DESIGN AND LAYOUT CHAPTER 1 Penny Whetton, Paul Holper Alicia Annable, Liz Butler and Siobhan Duff y CHAPTER 2 John Clarke, Leanne Webb, and Kevin Hennessy EDITORIAL SUPPORT CHAPTER 3 Rob Colman, Aurel Moise, Scott Power, Stephanie Baldwin Karl Braganza and Ian Watterson CHAPTER 4 Karl Braganza, Brad Murphy, Bertrand We acknowledge the World Climate Research Programme’s Timbal, Pandora Hope, Andrew Dowdy, Working Group on Coupled Modelling, which is responsible Kevin Hennessy, Jonas Bhend and for CMIP, and we thank the climate modelling groups (listed in Dewi Kirono Table 5.2.2 of this Report) for producing and making available their model output. For CMIP, the U.S. Department of Energy’s CHAPTER 5 Aurel Moise, Jonas Bhend, Ian Watterson Program for Climate Model Diagnosis and Intercomparison and Louise Wilson provides coordinating support and leads development of software infrastructure in partnership with the Global CHAPTER 6 Jonas Bhend, Ian Watterson, Michael Grose, Organization for Earth System Science Portals. Marie Ekström and Penny Whetton CHAPTER 7 CITATION 7.1 Ian Watterson, Tony Rafter, Louise Wilson, Jonas Bhend CSIRO and Bureau of Meteorology 2015, Climate Change and Craig Heady in Australia Information for Australia’s Natural Resource Management Regions: Technical Report, CSIRO and Bureau 7.2 Penny Whetton, Aurel Moise, Dewi Kirono, Tony Rafter, of Meteorology, Australia Louise Wilson, Kevin Hennessy, Jonas Bhend, Pandora Hope, Bertrand Timbal, Andrew Dowdy, Ian Watterson, DISCLAIMER Michael Grose, Sugata Narsey and Janice Bathols No responsibility will be accepted by CSIRO or the Bureau 7.3 Kathy McInnes, Aurel Moise, Debbie Abbs, Bertrand Timbal, Pandora Hope, Andrew Dowdy and Louise of Meteorology for the accuracy of the projections in or Wilson inferred from this Report, or for any person’s reliance on, or interpretations, deductions, conclusions or actions in 7.4, 7.5 & 7.6 Dewi Kirono and Louise Wilson reliance on, this Report or any information contained in it. technical report 1 TABLE OF CONTENTS EXECUTIVE SUMMARY . .5 CHAPTER 1 INTRODUCTION . 11 CHAPTER 2 USER NEEDS AND REGIONALISATION . 14 2.1 Assessing user needs . 14 2.2 Meeting user needs . .15 2.3 Sub-dividing Australia . 16 CHAPTER 3 GLOBAL CLIMATE CHANGE SCIENCE . 23 3.1 Factors driving climate variability and change . 23 3.1.1 Internal (“unforced”) climate variability . 23 3.1.2 External forcing factors . 24 3.2 Emissions scenarios and climate models . 25 3.2.1 Future scenarios of greenhouse gas concentrations . 25 3.2.2 Global climate models . 27 3.3 Introduction to climate model ensembles and to the CMIP5 ensemble . 28 3.3.1 The Coupled Model Intercomparison Project Phase 5 (CMIP5) . 28 3.4 Observed global trends and their attribution . 32 3.5 Global climate change projections . 34 3.6 Comparison of CMIP3 and CMIP5 global projections . 36 3.6.1 Global sensitivity of the CMIP3 and CMIP5 models . 36 3.6.2 Model responses to global warming in the Asia-Pacific region . 37 CHAPTER 4 UNDERSTANDING RECENT AUSTRALIAN CLIMATE . .40 4.1 Australian climate variability . 40 4.1.1 Tropical modes . 40 4.1.2 Extra-tropical modes . 41 4.2 Observed trends and attribution in the Australian region . 42 4.2.1 Temperature . 42 4.2.2 Rainfall . 43 4.2.3 Changes in circulation in the Australian region and their possible association with rainfall trends . 46 4.2.4 Drought . 48 4.2.5 Snow . 49 4.2.6 Surface winds over continental Australia . 49 2 CLIMATE CHANGE IN AUSTRALIA 4.2.7 Tropical cyclones . 49 4.2.8 East coast lows . 49 4.2.9 Solar radiation . 50 4.2.10 Surface humidity . 50 4.2.11 Pan evaporation . 50 4.2.12 Fire weather . .51 CHAPTER 5 EVALUATION OF CLIMATE MODELS . 53 5.1 Introduction . 53 5.2 Evaluation based on climatological characteristics . 53 5.2.1 Assessment of historical mean climatologies: temperature, rainfall and mean sea level pressure . 54 5.2.2 Assessment of spatial structure of historical mean climatologies: M-scores for rainfall and temperature. 59 5.2.3 Assessment of annual cycles of historical climate: rainfall and temperature . 61 5.2.4 Assessment of additional climate features and associated skill scores . 63 5.3 Evaluation of simulated rainfall and temperature trends . 70 5.4 Evaluation of extremes in climate models . 72 5.5 Evaluation of downscaling simulations . 73 5.6 Synthesis of model evaluation . 74 CHAPTER 6 CLIMATE CHANGE PROJECTION METHODS . 78 6.1 Limitations and uncertainties in climate change data . 78 6.1.1 Sources of uncertainty . 78 6.1.2 Interpretation of ranges of change in projections . 79 6.2 Regional projection methods . 80 6.2.1 Overview and comparison of existing regional projection methods . 80 6.2.2 Projection methods used in this Report . ..