Eighty leading researchers have called on Australia's governments to "acknowledge the gravity of the threat posed by climate change" and cut greenhouse gases "to safeguard against catastrophe".

An open letter, signed by present and recent Australian Research Council laureates, said while many factors contributed to the bushfire crisis, "the role of exceptional heat and dryness cannot be ignored".

Scientists say the role of 'exceptional heat and dryness' can't be ignored as factors contributing to the bushfire crisis - and nor can the need to reduce carbon emissions here and abroad. Credit:weatherzone

"Temperatures nearly everywhere on Earth have been rising for decades, a clear result of the build-up of greenhouse gases in the atmosphere from fossil fuel use and other human activities," it said.

Bushfires have burnt through about 12 million hectares across Australia this season, or about 1.5 times the size of Tasmania. The unprecedented scale of the fires came as the country recorded its hottest and driest year in 2019, the Bureau of Meteorology said earlier this month.