A recent analysis indicates that human-caused global heating made the intense heatwave that impacted much of Australia in early January five times more likely.
Extreme Heat Across Australia
The heatwave, the most severe since the 2019-20 “black summer,” saw temperatures exceed 40C in major cities like Melbourne and Sydney. Even more extreme heat affected regional areas of Victoria and New South Wales, as well as Western Australia, South Australia, and Tasmania. The heat in Victoria preceded bushfires that burned through 400,000 hectares and destroyed almost 900 buildings.
The Role of Climate Change
Researchers with the World Weather Attribution (WWA) found that greenhouse gas emissions had a greater impact on the heatwave than the effects of a weak La Niña, which typically brings milder temperatures to the region. The analysis suggests the climate crisis increased the extreme heat by approximately 1.6C, while La Niña likely lowered maximum temperatures by 0.3 to 0.5C.
“There was definitely a signal of human-induced climate change behind this event,” stated Prof Sarah Perkins-Kirkpatrick, a climate scientist at the Australian National University.
Looking Ahead
Based on the WWA analysis, Australians could expect to experience heatwaves of similar intensity approximately once every five years in the current climate. However, if global temperatures were to rise by 2.6C above pre-industrial averages – a scenario predicted by the end of the century based on current emission trends – similar heat events could occur every second year. The report’s authors noted that while their techniques are well-established, the study itself has not yet undergone peer review.
Frequently Asked Questions
What caused the January heatwave in Australia?
The heatwave was caused by a combination of factors, but analysis suggests human-caused global heating was the primary driver, making the event five times more likely. The effects of a weak La Niña were partially offset by the impact of greenhouse gas emissions.
How did the heatwave impact Victoria?
In Victoria, the extreme heat preceded bushfires that burned through 400,000 hectares and destroyed almost 900 buildings.
What did researchers say about the increasing frequency of heatwaves?
Researchers suggest that, in the current climate, Australians can expect heatwaves of similar intensity roughly once every five years. If the world warms 2.6C above pre-industrial levels, similar events could occur every second year.
As the climate continues to change, how will communities adapt to increasingly frequent and intense heatwaves?
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