New climate research raises the alarm on the risks of delaying net zero, with extreme heatwaves set to continue worsening for at least 1,000 years if this key climate goal is not reached soon.
Net zero, according to the United Nations, means cutting carbon emissions to a small amount of residual emissions that can be absorbed and durably stored by nature and other CO2 removal measures, resulting in zero new emissions in the atmosphere. While the organisation advocates for front-loading emissions reductions, their goal of net zero by 2050 is on the high side of scenarios examined in the new study.
Drawing on advanced climate modelling carried out by the ARC Centre of Excellence for 21st Century Weather and the Commonwealth Scientific and Industrial Research Organisation – a project that was reported on by SciTechDaily – researchers tested a series of net zero years between 2030 and 2060 to determine how timing will impact outcomes.
Every scenario showed the same pattern: the more net zero is delayed, the more frequent and severe once-rare extreme heatwave events will become.
For more vulnerable countries like those near the equator, delaying until 2050 or later could mean record-breaking heatwave events every year or more, explained co-author Dr Andrew King, a researcher at the University of Melbourne.
[See more: Extreme heat is more deadly than we thought, studies show]
In addition to heatwaves becoming hotter, longer and more frequent with each five-year delay of net zero, the researchers also found that long-term warming in the Southern Ocean could continue to worsen heatwaves even after we reach net zero.
None of the millennia-long scenarios showed meaningful decline in extreme heat events back down to pre-industrial levels.
“While our results are alarming, they provide a vital glimpse of the future, allowing effective and permanent adaptation measures to be planned and implemented,” Sarah Perkins-Kirkpatrick, lead author and Australian National University professor, told SciTechDaily.
“It is still vitally important we make rapid progress to permanent net zero, and reaching global net zero by 2040 at the latest will be important to minimise the heatwaves severity.”
Acting sooner will also minimise the cost of adaptation, King noted, explaining that the infrastructure, housing and health services needed to protect people from extreme heat will “look quite different in terms of scale, cost and the resources required” the longer we delay. “This adaptation process,” he emphasised, “is going to be the work of centuries, not decades.”
