Graph of the Day: Climate change stoking extreme heat in Australia

Compared to the last few Australian summers, the 2014-15 season has gone gently on us, so far, with relatively few extreme heat events. But we shouldn’t be fooled. According to the latest research released by Australia’s Climate Council, the scientific evidence linking man-made climate change and extreme heat is now “overwhelming”.

In a report titled “Quantifying the Impact of Climate Change on Extreme Heat in Australia,” the Climate Council details findings showing the number of record hot days Australia experiences every year has doubled over the last 50 years.

To put it plainly, climate change is making Australia hotter, with hot days happening more often and  heatwaves becoming hotter, longer and more frequent.

And that record year of extreme heat the nation experienced 2013 – that would have been virtually impossible without climate change.

“The evidence on the link between climate change and extreme heat is stronger than ever, and in fact is overwhelming,” the report says.

“There is a ‘calculable’ human influence on the record hot summer of 2012/2013.

“Without this influence, the record temperatures Australia experienced in that period would occur only once in 12,300 years,” the report says.

Now, according to the IPCC, 1-in-20 year extreme hot days are expected to occur every two to five years by the middle of the century – that is, four to 10 times more often.

“Without effective action on climate change, today’s extreme heat will become commonplace, occurring every summer across the continent in the last decade or two of this century,” the Climate Council says.

“Towards the end of the century,” says the report, “the occurrence and intensity of extreme heat will depend strongly on our success, or not, in reducing greenhouse gas emissions.”