CRANKING UP THE INTENSITY: CLIMATE CHANGE AND EXTREME WEATHER EVENTS CLIMATECOUNCIL.ORG.AU Thank you for supporting the Climate Council. The Climate Council is an independent, crowd-funded organisation providing quality information on climate change to the Australian public. Published by the Climate Council of Australia Limited ISBN: 978-1-925573-14-5 (print) 978-1-925573-15-2 (web) © Climate Council of Australia Ltd 2017 This work is copyright the Climate Council of Australia Ltd. All material Professor Will Steffen contained in this work is copyright the Climate Council of Australia Ltd Climate Councillor except where a third party source is indicated. Climate Council of Australia Ltd copyright material is licensed under the Creative Commons Attribution 3.0 Australia License. To view a copy of this license visit http://creativecommons.org.au. You are free to copy, communicate and adapt the Climate Council of Australia Ltd copyright material so long as you attribute the Climate Council of Australia Ltd and the authors in the following manner: Cranking up the Intensity: Climate Change and Extreme Weather Events by Prof. Lesley Hughes Professor Will Steffen, Professor Lesley Hughes, Dr David Alexander and Dr Climate Councillor Martin Rice. The authors would like to acknowledge Prof. David Bowman (University of Tasmania), Dr. Kathleen McInnes (CSIRO) and Dr. Sarah Perkins-Kirkpatrick (University of New South Wales) for kindly reviewing sections of this report. We would also like to thank Sally MacDonald, Kylie Malone and Dylan Pursche for their assistance in preparing the report. Dr David Alexander Researcher, — Climate Council Image credit: Cover Photo “All of this sand belongs on the beach to the right” by Flickr user Rob and Stephanie Levy licensed under CC BY 2.0. This report is printed on 100% recycled paper. facebook.com/climatecouncil [email protected] twitter.com/climatecouncil climatecouncil.org.au Dr Martin Rice Head of Research, Climate Council CLIMATE COUNCIL I Contents Key Findings ....................................................................................................................................................................................ii Introduction ......................................................................................................................................................................................1 1. The Link Between Climate Change and Extreme Weather Events .......................................................................... 4 2. Increasing Severity and Intensity of Extreme Weather in Australia ......................................................................11 2.1 Extreme Heat and Heatwaves 12 2.1.1 Land 12 2.1.2 Marine 17 2.2 Bushfires 18 2.3 Drought 22 2.4 Extreme Rainfall 25 2.5 Storms 28 2.6 Sea-level Rise and Coastal Flooding 31 3. Impacts of Extreme Weather Events ............................................................................................................................... 34 3.1 Extreme Heat and Heatwaves 34 3.1.1 Land 34 3.1.2 Marine 39 3.2 Bushfires 41 3.3 Drought 47 3.4 Extreme Rainfall 49 3.5 Storms 51 3.6 Sea-level Rise and Coastal Flooding 52 4. How Much Worse Will Extreme Weather Events Become in Australia? ............................................................... 59 4.1 General Projections 62 4.1.1 Heatwaves 62 4.1.2 Bushfires 64 4.1.3 Drought 66 4.1.4 Extreme Rainfall 67 4.1.5 Storms 68 4.1.6 Sea-level Rise and Coastal Flooding 69 4.2 State-by-State Projections 72 4.2.1 Queensland 72 4.2.2 New South Wales 73 4.2.3 Australian Capital Territory 74 4.2.4 Victoria 75 4.2.5 South Australia 76 4.2.6 Western Australia 77 4.2.7 Northern Territory 78 4.2.8 Tasmania 79 5. Tackling Climate Change is Critical for Protecting Australians ............................................................................80 References ...................................................................................................................................................................................... 82 Image Credits ................................................................................................................................................................................ 93 II CRANKING UP THE INTENSITY: CLIMATE CHANGE AND EXTREME WEATHER EVENTS Key Findings Climate change is influencing all extreme Some of the most severe climate impacts 1 weather events in Australia. 2 the world has experienced have occurred in 2016. › All extreme weather events are now occurring in an atmosphere that is warmer and wetter than it › Arctic sea ice reached its lowest annual extent on was in the 1950s. record while record sea surface temperatures drove the worst coral bleaching event in the Great Barrier › Heatwaves are becoming hotter, lasting longer and Reef’s history. occurring more often. › Tropical Cyclone Winston was the most intense › Marine heatwaves that cause severe coral cyclone to hit Fiji on record, while Hurricane Otto bleaching and mortality are becoming more was the southernmost hurricane to hit Central intense and occurring more often. America on record. › Extreme fire weather and the length of the fire › Canada experienced its costliest wildfire in history season is increasing, leading to an increase in in Fort McMurray, forcing the evacuation of almost bushfire risk. 90,000 people. › Sea level has already risen and continues to rise, › The US state of Louisiana experienced 1-in-500 driving more devastating coastal flooding during year rains that brought severe flooding leading to storm surges. 30,000 rescues and 13 deaths. KEY FINDINGS III Across Australia, extreme weather events The impacts of extreme weather events 3 are projected to worsen as the climate 4 will likely become much worse unless warms further. global greenhouse gas emissions are reduced rapidly and deeply. › Extreme heat is projected to increase across the entire continent, with significant increases in the › Burning of coal, oil and gas is causing length, intensity and frequency of heatwaves in temperatures to rise at unprecedented rates and many regions. is making extreme weather events more intense, damaging and costly. › The time spent in drought is projected to increase across Australia, especially in southern Australia. › Major emitters including China and the European Extreme drought is expected to increase in both Union are leading action on climate change, but frequency and duration. Australia is lagging well behind and is on track to even miss its very weak target of a 26-28% › Southern and eastern Australia are projected to reduction in emissions by 2030. experience harsher fire weather. › Australia is expected to do its fair share to meet the › The intensity of extreme rainfall events is projected global emissions reduction challenge by cutting its to increase across most of Australia. emissions rapidly and deeply. › The increase in coastal flooding from high sea › Phasing out ageing, polluting coal plants and level events will become more frequent and more replacing them with clean, efficient renewable severe as sea levels continue to rise. energy sources such as wind and solar is imperative for stabilising the climate and reducing the risk of even worse extreme weather events. climatecouncil.org.au 1 CRANKING UP THE INTENSITY: CLIMATE CHANGE AND EXTREME WEATHER EVENTS Introduction 2016 was the hottest year on record Australia is one of the most vulnerable globally, yet again. Global average developed countries in the world to the temperature has risen by about impacts of climate change. Heatwaves in 1.1°C above the pre-industrial Australia are becoming longer, hotter and baseline, with most of the warming starting earlier in the year. In the populous occurring since the 1950s. The south of the country, dangerous bushfire rapidly warming climate is driving a weather is increasing and cool season wide array of impacts, many of them rainfall is dropping off, stretching firefighting associated with worsening extreme resources, putting lives at risk and presenting weather events. challenges for the agriculture industry. The nation has also been hit with a series of destructive storms in recent times. In September 2016, a vicious extra-tropical cyclone roared across South Australia, knocking down power lines and triggering a state-wide blackout, leaving 1.7 million people without power. Just a few months earlier, a deep east coast low sent record- high waves pounding onto the New South Wales coast, causing five deaths as well as significant loss of coastal property. These extreme weather events are part of a disturbing global pattern (Figure 1). In the latter part of 2016, Santiago (Chile) experienced its hottest day on record, while dry and hot conditions led to the costliest wildfire in Canada earlier in the year. Some of the most intense, prolonged heatwaves ever recorded have been experienced in the Middle East and the Indian subcontinent. Extreme rainfall caused severe flooding and deaths in France and the United States. Some of the most intense tropical cyclones on record occurred in the Atlantic and Pacific basins. INTRODUCTION 2 The evidence for the link between climate change and extreme weather is already very All extreme strong for heatwaves and bushfire weather, and it is getting stronger for intense cyclones weather events and heavy rainfall events. All extreme weather events are now occurring in an are now occurring atmosphere that is warmer and wetter than it was in the 1950s. Generally, this