Australia’s eastern coast capitals could see heatwave deaths spike by up to 500 per cent if governments don’t take adaptation and mitigation actions, according to a new study published in PLOS Medicine.
In what is thought to be by far the largest international study on the health impacts of heatwaves, researchers from across the world, including Australia’s Monash University, projected heatwave death rates under different scenarios including greenhouse gas emissions, preparedness and adaptation strategies, and population density.
They found that without mitigating climate emissions or adopting adaptation measures, Sydney, Melbourne and Brisbane could see heatwave deaths increase by 471 per cent between 2031-2080, compared with 1971-2020.
Even with adaptation measures, low population growth and meeting Paris agreement targets, heatwave deaths are expected to rise by at least 50 per cent.
Study lead and Monash University associate professor Yuming Guo said the deadly heatwaves that occurred across Europe, Japan, India and Canada in the past month highlighted the importance of the study.
“Future heatwaves in particular will be more frequent, more intense and will last much longer,” Dr Guo warned.
“If we cannot find a way to mitigate the climate change… and help people adapt to heatwaves, there will be a big increase of heatwave-related deaths in the future…”
He said if the Australian government did not put more effort into reducing the impact of heatwaves, the outcome would be more people dying.
The results were worse for some other countries, particularly “poor countries located around the equator”, Dr Guo said.
Colombia in South America, for example, was predicted to have death rates increase by 2000 per cent in a high emissions, low adaptation, high population growth scenario.
Co-author associate professor Antonio Gasparrini, from the London School of Hygiene & Tropical Medicine, said the dramatic increase in mortality could be tempered.
“The good news is that if we mitigate greenhouse gas emissions under scenarios that comply with the Paris Agreement, then the projected impact will be much reduced,” he said.
The study also suggested six adaptation interventions, which would be especially relevant for developing countries in tropical and subtropical regions:
- Individual: information provision, adverting
- Interpersonal: Information sharing; communication; persuasive arguments; counselling; peer education
- Community: Strengthening community infrastructure; encouraging community engagement; developing vulnerable people group; livelihoods; neighbourhood watch
- Institutional: Institutional policies; quality standards; formal procedures and regulations; partnership working
- Environmental: Urban planning and management; built environment; planting trees; public available drink water; house quality
- Public policy: Improvement of health services; poverty reduction; redistribution of resources; education; heatwave-warning system