More megafires loom in Australia’s future
Nine decades of fire data reveals we are increasingly in danger of widespread bushfires.
Australian bushfires are getting worse and it’s being driven by climate change, according to a massive analysis of 90 years’ worth of fire data.
Not only has the number of megafires in Australia spiked since 2000, but a greater expanse of land is being burnt, and they’re happening more and more in autumn and winter. Even the cooler La Niña seasons don’t offer much respite – in fact, the data shows that fires tend to be worse directly after La Niña years.
The researchers, led by the CSIRO’S Pep Canadell, warn that we should prepare for another severe fire season in the summer of 2022/23.
“Our results really underscore the overwhelming role of climate change and associated changes of fire weather in driving the observed increased trends in burnt areas,” says Canadell.
“Understanding these trends will help to inform emergency management, health, infrastructure, natural resource management and conservation.”
Though we have always seen large fires in Australia, since 2000 the data shows that megafire seasons – where more than one million hectares of forests are burnt – have increased significantly. The study, published in Nature Communications and focusing on Australia’s forests, found that of four forest megafires since 1930, three have happened since 2000.
Nine of the 11 biggest fire years, each with more than 50 million hectares burned, have also occurred since 2000.
The team found that from 1988 to 2018, Australian forests saw a 350% increase in burned areas – if the Black Summer fires of 2019/20 are included, that number jumps to 800%.
The cooler months don’t even provide a break – since 1988, autumn fires have burnt three times more forest than previously, and winter fires have burnt five times more forest.
Forests are burning more frequently, too. There are now fewer years between them, with fire returning to the same area again and again.
“There are now regions in the southeast and south with fire intervals shorter than 20 years, preventing certain types of vegetation to reach maturity and therefore posing a risk to local ecosystem collapse,” says Canadell.