The temperature in the South Australian city of Port Augusta on January 30 peaked at 50.0°C — just 0.7°C degrees short of the highest-ever recorded in this country.

Was this simply “weather” of the kind we’ve always enjoyed or suffered? Or was something much more dangerous at work?

Port Augusta’s maximum that day marked the sweltering high point of two heatwaves that roasted Australia’s main settled regions last month. These events weren’t unprecedented — just the most extreme since 2019‒2020.

But each had an intensity, geographical extent and duration experienced only a few times during the whole 20th century. So, is there some definite trend — and human factor — involved?

Professor Steve Turton, from Central Queensland University, explained the science in the Conversation on January 27. Each summer, Turton noted, monsoonal troughs over northern Australia push upper-atmosphere high pressure systems further south. Air from these systems then flows down over central, southern and eastern regions. As it descends, compression raises its temperature.

Nothing unusual there. But last month, the high pressure was further south than normal. And critically, blocking weather systems held it in place over the continent while temperatures built up. Still, that was nothing really out of the ordinary for an Australian summer.

But enter climate change. As analysed by the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australian land temperatures warmed on average by about 1.6°C between 1850‒1900 and 2011‒2020. “Very high........

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