March 12, 2025
Living in Australia, we are no strangers to climate extremes. This summer, we’ve seen record-breaking heat both on land and the adjacent oceans, major floods in the north, and a feeling that the climate is shifting under our feet—or, in this case, beneath the waves.
As a climate researcher, I’ve spent years studying how human-driven warming is altering our climate. The recent record sea surface temperatures over the northwest region of Australia during the September to January season of 2024-25 provide yet another stark example. Without climate change, an event this extreme could have occurred—but it would have been almost vanishingly rare. However, our analysis based on the peer-reviewed methodology shows that human-induced climate change contributed to about two-thirds the observed temperature anomaly of 1.34°C (relative to 1911-1960 average). This means that what was once an extraordinary outlier with a near-zero probability of occurring is becoming part of our new normal.
Looking ahead, the risk only grows. At just 1.5°C of global warming—only slightly above today’s levels—global climate models suggest sea surface temperatures like this season’s would be close to the average for the region. At 2.0°C, more than a third of all seasons would be even warmer than the observed. And at 4.0°C, models suggest we will not see sea surface temperatures as “cool” as 2024-25.
This is not a distant future scenario; it’s a trajectory we are already on if global emissions continue unabated.
Why does this matter? Warmer ocean temperatures drive more intense cyclones, disrupt marine ecosystems, and alter rainfall patterns in ways that directly impact communities, industries, and biodiversity. As we reflect on this summer’s extremes, it’s clear that the choices we make today—about emissions, adaptation, and resilience—will shape the future of our climate, our coasts, and our way of life.
Dr Surendra Rauniyar, Research Scientist, Australian Bureau of Meteorology
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