Climate change has led to the bushfire boom in Australia over the past three decades, which has seen forest area burned annually increase by 800%, according to a new CSIRO study.
The research is the first of its kind, combining analysis of past forest fire sites with eight factors of fire activity, including climate, fuel accumulation, ignition and prescribed burning.
More than 30 years of satellite data and 90 years of ground-based data sets from climate and weather observations, and simulated fuel loads for Australian forests, formed the basis of the research, which enabled researchers to ” identify increases induced by climate change compared to natural variability.
Comparing the first half (1988 to 2001) with the second half (2002 to 2018) of the record studied, research has shown that the average annual forest area burned in Australia has increased by 350% and 800% including 2019.
A lengthening of the fire season towards fall and winter has also been identified, along with an increase in fire activity in cooler and warmer regions, including Tasmanian alpine forests and tropical forests. wetlands of Queensland.
Research has shown a five-fold increase in the average annual area burned in the winter and a three-fold increase in the fall, with spring and summer being ten-fold.
CSIRO scientist Pep Canadell said the research was one of the most in-depth studies of its kind to date and was important for understanding how continuing climate change could impact the future fire activity.
“While the eight drivers of fire activity played varying roles in influencing forest fires, climate was the determining factor in fire activity,” said Dr. Canadell.
“The results also suggest that the frequency of mega-forest fires is expected to continue under predicted future climate changes.”
In the past 90 years, three of the four mega years of fires have occurred after 2000. A mega year of fire is defined as the cumulative area of ââforest burned in a year of more than one million. hectares.
Australia’s average temperature has risen 1.4 degrees since 1910, with episodes of extreme heat rapidly increasing, while precipitation has declined in the southern and eastern parts of the continent.
Globally, fire activity is declining, however, the extent of wildfires in Australia is increasing.
“In Australia, the frequency of fires has increased rapidly in some areas and there are now areas in the southeast and south with fire intervals of less than 20 years,” said Dr Canadell.
“This is important because it means that certain types of vegetation will not reach maturity and it could endanger ecosystems.
âUnderstanding these trends will help inform emergency management, health, infrastructure, natural resource management and conservation. ”