Climate change is the main driver behind Australia having more regular big bushfires and blazes causing greater forest destruction, the nation’s science agency has confirmed.
The agency flags a trend of frequent “megafires,” and increased burned areas are “likely to continue,” with considerable implications for emergency management, health, infrastructure, natural resource management and conservation.
A report published in Nature Communications found a lengthening of the fire season towards autumn and winter and more fire activity occurring in cooler months
Yet spring and summer contributed about 10 times more to an increase in burned areas, the report says.
Dr Pep Canadell, a CSIRO scientist, said climate was “the overwhelming factor driving fire-activity”.
“The results also suggest the frequency of forest megafires are likely to continue under future projected climate change,” Canadell said.
The research was based on 32 years of satellite data and 90 years of ground-based datasets from climate and weather observations, as well as simulated fuel loads for Australian forests.
When scientists compared data from 1998 to 2001 with data from 2002 to 2018, the research showed Australia’s annual forest burned area increased 350%.
With research that included 2019, the figure rose to 800%.
The scientists highlight a rise in Australia’s mean temperature by 1.4 °C since 1910 alongside a fall in rainfall in the southern and eastern regions of the continent, particularly during cooler months.
Candell said fire frequency had increased rapidly in some geographies.
“There are now regions in the southeast and south with fire intervals shorter than 20 years,” Canadell said.
“This is significant because it means some types of vegetation won’t reach maturity and this could put ecosystems at risk.”