‘Damned if we do but completely stuffed if we don’t’: heatwaves will worsen longer net zero is delayed | Climate crisis

Heatwaves will become hotter, longer and more frequent as net-zero emissions are reached globally, new research suggests.

Scientists from the ARC Center of Excellence for 21st Century Weather and Australia’s national science agency, CSIRO, simulated the response to heatwaves over the next 1,000 years, examining the differences for each five-year delay in reaching net zero between 2030 and 2060.

The research, published in the journal Environmental Research Climate, found that for countries close to the equator, delaying carbon neutrality until 2050 would result in heatwaves that shatter current historical records at least once a year.

The study also suggests that heatwaves will not return to pre-industrial conditions until at least a millennium after net zero is reached, which “seriously challenges the general belief that post-net zero conditions will begin to improve for near future generations.”

“The problem with net zero and heatwaves is that we’re damned if we do it, but we’re absolutely stuffed if we don’t,” said the study’s lead author, Professor Sarah Perkins-Kirkpatrick of the Australian National University. “We are already facing some warming. »

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Stabilizing global warming at 1.5°C or 2°C would still have consequences “that we have not yet experienced, including even more serious heat waves”, she declared. “The fact is that if we delay net zero – for up to 30 years and even longer – these impacts will only get worse. We’re already locked into some, but the longer we leave net zero, the worse the situation will be.”

“[In Australia] Basically the Coalition is saying: net zero is pointless, it’s pointless, it’s not worth it, it’s going to cost us too much money,” she said. “Well, it’s going to cost us even more if we don’t even get to net zero by 2050.”

“The positive side of this type of study, if there is one, is that we have time to adapt…so when these heat waves come, we are as prepared for them as possible,” she said. “We know the impacts of heat waves – there is so much knowledge about the health impacts, the ecosystem impacts, the financial services impacts.

“What those coping strategies look like remains to be seen,” she said. “These conversations can start now.”

The modeling was carried out using Australia’s global climate simulator, known as Access, and defined a heatwave as at least three consecutive days where temperatures are above the 90th percentile of the maximum temperature.

Professor David Karoly, a decorated climate change scientist and Climate Council adviser, who was not involved in the research, said the results were not surprising.

“There is a clear relationship between cumulative emissions of carbon dioxide into the atmosphere and global average temperatures,” he said.

Karoly added that the study results were interesting, but there were modeling uncertainties related to potentially important processes such as changes in precipitation, because the geographic representation of Australia and other regions in the Access model was of lower resolution than other climate simulators.