HEAT!!! The Australian Experience Professor Will Steffen Climate
Dec 24, 2015
Outline of Talk
1. Extreme heat and heatwaves in Australia
2. Consequences for Australians
3. Future heat: risks and responses
Heatwaves
Heatwaves are becoming more intense, lastinglonger and occurring more often. More frequent and hotter days are projected for the future. CSIRO and BoM 2015
2013: Australia’s Hottest Year on RecordVirtually Impossible without Climate Change
Source: Knutson et al. 2014
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Bushfires and Climate Change
• Climate change makes bushfire conditions worse by increasing the frequency of very hot days.
• Between 1973 and 2010 the Forest Fire Danger Index increased significantly at 16 of 38 weather stations across Australia, mostly in the southeast. None of the stations showed a significant decrease.
• Projected increases in hot days across Australia, and in dry conditions in the southwest and southeast, will very likely lead to more days with extreme fire danger in those regions.
Extreme heat and health
• Extreme heat causes more deaths than any other natural hazard in Australia.
• Recorded deaths from specific extreme heat events:374 excess deaths, Melbourne, Jan-Feb 200923% increase in deaths, Brisbane, Feb 2004110 excess deaths, Sydney, Jan 1994
• Without adaptation, heatwaves projected to cause over 400 excess deaths per year by 2050 in Victoria along (a southern Australian state).
Sources: DHS 2009; Tong et al. 2010; Gosling et al. 2007; Keating and Handmer 2013
Extreme heat and worker productivity
• Extreme heat in 2013/2014 drove an annual economic burden of nearly $8 billion via worker productivity losses
• Heat stress in northern Australia has reduced labour capacity by 10% in past few decades; further 10% drop projected by 2050
• Loss of worker productivity globally due to heat stress projected to be as high as USD 1 trillion by 2030.
Sources: Zander et al. 2015; Dunne et al. 2013; Kjellstrom and McMichael 2013
Infrastructure damage from the 2009 Melbourne heatwave
• An estimated 500,000 residents were without electricity on evening of 30 Jan.
• Extensive damage to railways:29 cases of rail tracks bucklingElectrical faults in signalingFailure of air-conditioning in more than 50% of trains
Extreme heat and natural ecosystems
• Marine heatwaves have caused repeated coral bleaching of the Great Barrier Reef since the late 1970s.
• Heatwaves combined with extended drought have caused mass mortality in koalas.
• Since 1994, more than 30,000 flying foxes have died in extreme heat. On 12 Jan 2012, over 3,500 were killed along the NSW coast when temperatures exceeded 42oC.
• In Jan 2010 in Western Australia, over 200 of the endangered Carnoby’s black cockatoos were killed when temperatures rose to 48oC.
Sources: Saunders et al. 2011; Welbergen et al. 2008; Gordon et al. 1998