If there was shock and awe last week when the Copernicus Climate Change Service announced that global average warming over the last twelve months — February 2023 to January 2024 — had exceeded 1.5 degrees Celsius (°C), it was likely because too many people had succumbed to the predominant but delusional policy-making narrative that holding warming to 1.5–2°C was still on the cards.

What does this symbolically important moment mean for the poor understanding of climate-risk analysis by Australian governments? To begin, the idea that emissions could continue till 2050 and still achieve the 1.5–2°C goal was always a con; now it is fully exposed.

One year of 1.5°C does not constitute a trend, which technically can only be seen in retrospect over 20 to 30 years of data. But with another hot year likely in 2024, the rate of warming accelerating, and a current peak in the Earth’s Energy Imbalance — which is an indicator of future warming — it is hard to disagree with the assessment of former NASA climate science chief James Hansen that the world has now reached the 1.5°C mark for all practical purposes.

When the 2015 global climate conference resulted in the Paris Agreement’s commitment to hold climate warming to the 1.5–2°C band, those numbers quickly became normalised as the sine qua non of climate policymaking. But that was a grand illusion on two counts:

The first was that 1.5°C was a safe or appropriate target. Sir David King, the former UK Chief Scientist had collaborated with the small-island states in the lead-up to the Paris conference in pushing the 1.5°C goal. But in 2021, The Independent journalist Donnachadh McCarthy reported that King “astounded me by saying he now realised this was wrong, and believes the passing of the Arctic tipping point has already been reached… He said the 1.1°C rise that we already have is too dangerous — and candidly admitted he believed US climate professor James Hansen had been right after all in 1988, when he warned the US Congress that we should not pass 350 ppm. We have now [in 2021] breached 415 ppm and are heading fast towards 500ppm” (emphasis added).

The second illusion was that there was any realistic hope of keeping warming to 1.5°C or even 2°C, given the decades of policy-making failure (see image), emissions breaking new records year after year, the reduced levels of aerosols which are masking warming, the political........

© Pearls and Irritations