Climate report says heat extremes to get far worse in Australia

February 13, 2015
Issue 
A firefighter fights a blaze near Northcliffe, WA in early February.

Partly due to luck, and partly due to the heroic efforts of severely overstretched firefighters, the huge bushfires that swept southern Western Australia in early February resulted in no loss of life. These devastating fires also provide a glimpse into our future on a warming planet unless we cut carbon emissions fast.

In the first five weeks of the year alone, WA authorities recorded . The largest fire, which threatened the town of Northcliffe, had . It was the biggest fire in the region for more than 50 years. As 130 Victorian firefighters were flown in to help, the state鈥檚 Fire and Emergency Services Commissioner said on February 2 that the situation was .

Is there a link between these particular bushfires and climate change? The only sensible answer to that is question is yes. Emphatically, yes. All weather is affected by climate change now because climate change is already here.

Across Australia, climate change and is making the bushfire season longer. As temperatures rise further, so too will the number of days that represent an extreme fire danger.

In its newly released Annual Climate Report 2014, the Bureau of Meteorology (BOM) said . It said that seven of Australia鈥檚 10 warmest years since records began in 1910 took place between 2002 and 2014.

The BOM said there is no doubt that Australia鈥檚 climate is getting steadily hotter: 鈥淲arming in the Australian region is very similar to that seen at the global scale, and the past year emphasises that the warming trend continues. Temperatures over Australia have risen by about one degree since the start of last century, with most of the warming occurring since 1950.鈥

Climate scientists are also getting better at quantifying just how much global warming is changing the climate. A new report by climate scientist Will Steffen, released by the Climate Council on February 5, said new methods are allowing scientists to work out how much climate change has influenced individual heat extremes in Australia.

The report discusses Australia鈥檚 warmest-ever year of 2013. Steffen refers to a 2014 study by Sophie Lewis and David Karoly. It concluded that 鈥渨ithout the human influence on climate, the record temperature Australia experienced in 2013 鈥. In essence, this means 鈥渢he 2013 record would not have occurred in the absence of climate change鈥.

Another 2014 study compared Australian temperature trends from 1860 to the present. It concluded 鈥渢he record hot year of 2013 in Australia was virtually impossible without the influence of climate change鈥.

A third study compared with past temperature records going back to 1955. Steffen said the 鈥渞esults showed that there is a 鈥榗alculable鈥 human influence on the hot Australian summer of 2012/2013鈥.

These new studies regarding the influence of climate change on single heat extremes come on top of the large and well-established body of research that shows the long-term warming trend. Steffen says that 鈥渞ecord hot days have doubled in Australia in the last 50 years, while record cold days have declined by a similar fraction鈥.

For Australia, the UN Intergovernmental Panel on Climate Change predicts that by 2050 extreme hot days that now take place every 20 years will take place every two to five years.

Without effective action on climate change, Steffen says Australia鈥檚 heat extremes will get worse: 鈥淭owards the end of the century, the occurrence and intensity of extreme heat will depend strongly on our success, or not, in reducing greenhouse gas emissions, mainly emissions of carbon dioxide.鈥

If carbon emissions do not fall dramatically, 鈥渢oday鈥檚 extreme heat will become commonplace, occurring every summer across the continent in the last decade or two of this century鈥.

Steffen said the evidence for climate change鈥檚 impact on Australia鈥檚 heat extremes is overwhelming: 鈥淓xtreme heat is becoming more frequent and more severe, and climate change is the primary reason.

鈥淭he case for action is just as overwhelming. Carbon emissions will need to be reduced rapidly and deeply, with most of the world鈥檚 economies essentially decarbonised by the middle of the century, if the climate system is to be stabilised and the worst of extreme heat in the second half of the century is to be avoided.鈥

[Download the Climate Council Report, ]

Like the article? Subscribe to 麻豆传媒 now! You can also us on Facebook and on Twitter.

You need 麻豆传媒, and we need you!

麻豆传媒 is funded by contributions from readers and supporters. Help us reach our funding target.

Make a One-off Donation or choose from one of our Monthly Donation options.

Become a supporter to get the digital edition for $5 per month or the print edition for $10 per month. One-time payment options are available.

You can also call 1800 634 206 to make a donation or to become a supporter. Thank you.