Study Identifies Cities Most Vulnerable to Rising Heatwave Mortality Due to Climate Change

Sydney: Human-induced climate change has significantly increased heatwave-related deaths, with urban populations facing the greatest risk, according to new research published on Tuesday.

Two separate studies conducted by the University of Queensland (UQ) examined the impact of extreme heat on mortality rates in Australia. The first study, carried out in collaboration with the Australian National University (ANU), analyzed data from a severe 2009 heatwave in southeastern Australia, as well as historical heatwave trends, to assess climate change's role in heat-related deaths.

During the 2009 heatwave, Melbourne recorded its highest-ever temperature of 46.4°C, while parts of Victoria endured 12 consecutive days of temperatures exceeding 40°C. Over a five-day peak period, Victoria saw an estimated 374 excess deaths due to the extreme heat.

The study found that climate change had directly contributed to a 20% increase in heatwave-related mortality during this event, highlighting the growing risks posed by rising global temperatures.

The second study, which analyzed two decades of data, identified specific populations in Australia most vulnerable to heatwave-related deaths. It found that city dwellers with low income, limited education, diabetes, and poor access to healthcare were at the highest risk.

Patrick Amoatey, a doctoral researcher at UQ and co-author of the study, explained that urban areas are particularly susceptible due to the prevalence of heat-absorbing surfaces such as roads, buildings, and railways, which contribute to the urban heat island effect.

Nicholas Osborne from UQ’s School of Public Health emphasized that extreme heat events, along with associated health risks, will become more frequent. "Our results suggest that heatwaves leading to increased mortality will occur more often than they did in the past," he said.

The researchers hope their findings will help communities and policymakers develop better strategies for heatwave preparedness and mitigation.

Heatwaves pose serious risks beyond human mortality, including drought, declining water quality, wildfires, power shortages, and agricultural losses. As climate change accelerates, experts stress the urgent need for adaptive measures to protect vulnerable populations.