Bushfires in Australia 2019/2020

The analysis finds that anthropogenic climate change has significantly increased the probability of extreme fire weather and heatwaves in southeastern Australia, while having no attributable trend in dry extremes. Specifically, the probability of a Fire Weather Index as high as in 2019/20 has increased by more than a factor of four since 1900. Heatwaves of similar intensity are now approximately 10 times more likely than they were around 1900. While climate change increased the overall risk, the specific severity of the 2019 event was further amplified by natural variability, specifically the Indian Ocean Dipole and the Southern Annular Mode.

• Anthropogenic climate change has significantly increased the probability of extreme fire weather risk in southeastern Australia. Climate models indicate the probability of a Fire Weather Index (FWI) as high as that seen in 2019/20 has risen by at least 30% since 1900, while observations suggest the probability has increased by more than a factor of four. For the Monthly Severity Rating, the probability has increased by more than a factor of nine compared to 1900.
• Human-induced climate change has made extreme heatwaves substantially more likely. Observations indicate that a heatwave of the intensity observed in 2019/20 would have been 1 to 2 ºC cooler at the start of the 20th century and is now about 10 times more likely than it was around 1900. Climate models, which may underestimate the trend, conclude that such a hot week is more likely by at least a factor of two.
• There is no attributable trend in dry extremes linked to climate change for the studied region. Both observations and ten climate models show non-significant trends regarding annual mean low precipitation and the driest months of the fire season (September-February).
• The extreme severity of the 2019 event was driven by a combination of anthropogenic climate change and natural climate drivers. Specifically, a record excursion of the Indian Ocean Dipole and a strong anomaly of the Southern Annular Mode together accounted for more than half of the drought's amplitude in the second half of 2019.

APA

World Weather Attribution (2020). Bushfires in Australia 2019/2020. https://www.worldweatherattribution.org/bushfires-in-australia-2019-2020/

Chicago

World Weather Attribution. Bushfires in Australia 2019/2020. 2020. https://www.worldweatherattribution.org/bushfires-in-australia-2019-2020/.

Wikipedia

{{cite report |author=World Weather Attribution |title=Bushfires in Australia 2019/2020 |date=10 January 2020 |url=https://www.worldweatherattribution.org/bushfires-in-australia-2019-2020/ |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{worldweatherattribution2020bushfires, author = {{World Weather Attribution}}, title = {{Bushfires in Australia 2019/2020}}, institution = {World Weather Attribution}, year = {2020}, month = jan, url = {https://www.worldweatherattribution.org/bushfires-in-australia-2019-2020/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }