New scientific research has delivered a stark warning about the long-term consequences of delaying climate action, revealing that heatwaves will become increasingly severe the longer it takes to reach net zero emissions globally.
The thousand-year heatwave legacy
Scientists from the ARC Centre of Excellence for 21st Century Weather and Australia's national science agency, CSIRO, have conducted groundbreaking simulations showing that heatwaves will not return to pre-industrial conditions for at least 1,000 years after net zero is achieved. This finding critically challenges the widespread assumption that climate conditions would quickly improve once emissions targets are met.
The research, published in the journal Environmental Research Climate, examined how heatwaves would evolve over the next millennium. The team specifically analysed the differences resulting from each five-year delay in reaching net zero between 2030 and 2060.
Immediate consequences of delayed action
According to the study's findings, countries near the equator would face particularly severe impacts. If net zero is delayed until 2050, these regions would experience heatwave events that break current historical records at least once every year.
Professor Sarah Perkins-Kirkpatrick of the Australian National University, the study's lead author, delivered a blunt assessment of the situation. "The thing with net zero and heat waves is: we're damned if we do, but we're completely stuffed if we don't," she stated. "We're already locked into a certain amount of warming."
Even if global heating is stabilised at 1.5°C or 2°C - the targets set in the Paris Agreement - we would still face impacts "that we haven't yet experienced, including worse heatwaves", Professor Perkins-Kirkpatrick explained.
Political and economic implications
The research comes amid ongoing political debates about the costs and timing of climate action. Professor Perkins-Kirkpatrick specifically addressed arguments against rapid decarbonisation, noting: "[In Australia] you have the Coalition basically saying: net zero is useless, it's pointless, it's not worth it, it's going to cost us too much money. Well, it's going to cost us even more if we don't even get to net zero by 2050."
The modelling was conducted using Australia's global climate simulator, known as Access. The study defined a heatwave as at least three consecutive days where temperatures exceed the 90th percentile for maximum temperature.
Scientific validation and adaptation urgency
Professor David Karoly, a distinguished climate change scientist and councillor with the Climate Council who was not involved in the research, confirmed the study's credibility. "There is a clear relationship between the cumulative emissions of carbon dioxide in the atmosphere and global mean temperatures," he stated.
Professor Karoly did note one caveat, explaining that there were uncertainties in the modelling relating to potentially important processes such as rainfall changes, as the geographical representation in the Access model was of lower resolution than some other climate simulators.
Despite the concerning projections, Professor Perkins-Kirkpatrick identified a potential silver lining. "The silver lining to this sort of study, if there is one, is that we have time to adapt... so when these heatwaves occur, we're as prepared for them as possible," she said.
She emphasised the extensive existing knowledge about heatwave impacts on health, ecosystems and financial services, while acknowledging that specific adaptation strategies still need development. "What those adaptation strategies look like - that remains to be seen," she admitted. "Those conversations can start now."
The research underscores the urgent need for both rapid emissions reduction and comprehensive adaptation planning to address the escalating heatwave threat that will persist for centuries, regardless of when net zero is ultimately achieved.
