A study carried out in Australia revealed that urban residents face a greater risk of death during extreme temperature events.
Researchers from the University of Queensland and Griffith University examined two decades of temperature and mortality data to identify which regions in Australia are more susceptible to heatwaves using a Heatwave Vulnerability Index (HVI).
They found a correlation between HVI and the rise in heatwave-related deaths across major cities such as Melbourne, Sydney, Adelaide, Brisbane, Hobart, Perth, and Darwin.
Even during mild heatwaves, there was a significant correlation between deaths and HVI in Australia's capital cities. The far north and southern regions of Western Australia showed a higher risk of fatalities, with critical areas in the capital cities of Victoria, Queensland and Tasmania.
The risk is elevated in cities due to the heat island effect, which results from more heat-absorbing surfaces like roads, buildings, and railway lines. The study referenced Greater London as an example, where the heat vulnerability index could forecast a rise in ambulance call-outs and mortality on heatwave days.
As heatwaves are more detrimental to human health than other heat-related extremes HVI is an important metric used to locate population's vulnerability to heatwaves.
Patrick Amoatey, the first author of the study said that while analysing data for more than 2,000 suburbs, they found city dwellers with low income, low education, diabetes and limited access to health services, were at the highest risk of heatwave related deaths.
This was the case for all of Australia’s capital cities, which are home to 70 per cent of Australia’s population, Amoatey said.
The study published in Environmental Impact Assessment Review, March 2025 examined the association between HVI and risk of heatwave-related deaths across Australia.
Higher mortality rates associated with extreme temperature heatwaves are projected to continue and researchers hoped that the research would help communities and health authorities to prepare for extreme temperature events.
A study published in Environmental Research Climate January 27, 2025 also examined the mortality burden of heatwaves in Australia. The study showed a 20 per cent increase in human induced climate change.
The study focused on excess heatwave related mortality in the state of Victoria that occurred during the 2009 southeast Australian heatwave.
Victoria experienced approximately 374 additional deaths over a five-day period, with peak temperatures soaring 12-15 degrees higher than usual. “Our results suggest heatwaves with associated periods of higher mortality will occur more often than they did in the past,” Nicholas Osborne, one of the authors said.