Australia's recent heatwave, a harrowing reminder of the 2019-20 Black Summer, was not just a natural occurrence. Human-induced global heating, according to a new analysis, made this intense heatwave five times more likely.
The heatwave, which saw temperatures soar above 40°C in major cities like Melbourne and Sydney, was a stark contrast to the milder conditions usually associated with a weak La Niña. In fact, the report by World Weather Attribution (WWA) suggests that greenhouse gas emissions played a more significant role than the La Niña effect, which typically brings cooler temperatures to mainland Australia.
But here's where it gets controversial: the report's authors claim that the climate crisis made the extreme heat about 1.6°C hotter, while the La Niña effect likely only lowered maximum temperatures by a fraction of that.
"There's no denying the human impact on this event," says Prof. Sarah Perkins-Kirkpatrick, a climate scientist at the Australian National University and co-author of the report. "Heatwaves, defined as three consecutive days of higher-than-average maximum temperatures, are a silent killer in Australia, claiming more lives than any other natural hazard."
Perkins-Kirkpatrick warns that the mentality of 'sucking it up' is no longer viable. "The heat is intensifying, and we must acknowledge our physical limits."
The report suggests that, in the current climate, Australians can expect heatwaves of similar intensity to occur approximately every five years. However, if global temperatures rise by 2.6°C above pre-industrial levels (a prediction based on current carbon emission trends), these extreme heat events could become an annual occurrence.
Friederike Otto, co-founder of WWA and a professor of climate science at Imperial College London, emphasizes the urgency: "Extreme heat is one of the deadliest weather phenomena, and with global warming, these changes are happening rapidly. It's crucial to highlight these shifts, even if the results are not surprising."
WWA, an international collaboration of scientists, utilizes weather observations and climate models to understand the impact of human-caused global heating on extreme weather events. Their work provides a stark reminder of the reality of climate change and the urgent need for action.
