Scientists have warned that extreme rains could become more common in eastern Australia, following heavy downpours from May 19-23 that caused widespread flooding, claimed five lives and left some 50,000 people stranded.
The warning is based on a recent rapid analysis by World Weather Attribution (WWA), a global research network that examines the role of climate change in extreme weather events.
WWA’s analysis shows that extreme four-day rainfall events, like the one that occurred in the state of New South Wales in May, are now around 10% more intense and twice as likely in today’s climate, which is 1.3° Celsius (2.3° Fahrenheit) warmer than in preindustrial times.
Report co-author Mariam Zachariah, from Imperial College London, said in a press release sent to Mongabay that it’s unclear how much climate change influenced the recent floods in NSW. “However, it is certain that floods in the state are causing serious harm and the risk of even more dangerous events needs to be taken seriously.”
The May rainfall damaged more than 10,000 properties and killed five people in the state, media reported. Farmers also lost their livestock and hundreds of residents had to flee to evacuation centers. Mongabay previously reported on floods devastating normally arid parts of the country, in addition to wildfires and cyclones, some of which have been attributed to climate change.
From May 19-23, coastal areas of NSW received 100 millimeters (4 inches) of rain per day. The WWA study showed such rainfall in the studied area has become relatively common in today’s climate, and is expected to occur once every 10 years, when analyzing April-June rainfall, and once every three years when looking at the whole year.
The researchers also examined whether the atmospheric circulation patterns driving heavy rainfall changed between two periods: 1950-1980 and 1994-2024. The latter is “marked by a stronger influence of climate change,” they write.
The analysis showed “signs of a seasonal shift,” the authors say: “atmospheric circulation patterns that could lead to similar heavy rainfall are now less common in March and more frequent in May.”
While the climate models don’t identify the exact influence of human-induced climate change in the May rainfall, the scientists said the lack of a clear trend might mean that other processes are in play.
“The weather in Australia is naturally chaotic. The country has always faced every kind of extreme weather — floods, tropical cyclones, bush fires, droughts, heatwaves,” report co-author Friederike Otto, also from Imperial College London, said in the release. “But with every ton of oil, coal and gas burned, they are getting more unpredictable and more dangerous, destroying lives and livelihoods across the continent.”
Co-author Kimberley Reid, from the University of Melbourne, said, “We do know that ongoing reliance on fossil fuels — whether burned or exported — will only make weather events more dangerous in Australia.”
Banner image of weather forecast from May 21 from the Australian Bureau of Meteorology via X.
This story first appeared on Mongabay
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