The records broken by 2013 would not have tumbled without the effects of climate change, a report from the Climate Council says

This article is more than 5 years old

This article is more than 5 years old

Australia’s hottest year on record would not have happened without climate change, according to a new report.

The country experienced its hottest day, month, season and calendar year in 2013, registering a mean temperature 1.2C above the 1961-90 average.

The Climate Council says recent studies show those heat events would have occurred only once every 12,300 years without greenhouse gas emissions from human activities.

“In fact, we can say the 2013 record year was virtually impossible without climate change; it wouldn’t have happened,” said Will Steffen, the author of Quantifying the Strong Influence of Climate Change on Extreme Heat in Australia.

“I mean, no one would bet on odds of one in nearly 13,000.”

Based on analyses of data and model outputs, the report says climate change triples the odds that heatwaves of the 2012-13 Australian summer will happen as frequently as they do.

It also doubles the chances of them being as intense.

“We’re looking at pretty hard numbers on the odds of those things happening without the underlying warming trend due to greenhouse gases,” Steffen said.

“In my view, it’s extremely powerful, conclusive evidence that not only is there a link between climate change and extreme heat, climate change is the main driver of it.”

Steffen found record hot days had doubled in Australia the past 50 years, and that during the past decade heat weather records were set three times more often than cold ones.

The report also says heatwaves across Australia are becoming hotter, lasting longer, occurring more often and starting earlier.

The Climate Council’s co-founder Tim Flannery said the research strengthened the case for immediate action on climate change.

“Australians are already feeling the impact of climate change making Australia hotter,” he said.

“Carbon emissions must be reduced rapidly and deeply if the worst of extreme heat in the second half of the century is to be avoided.”