A new study highlights that climate change is causing more frequent and severe heatwaves in Australia, with projections indicating a potential 190% increase in heat-related deaths in Sydney and Melbourne if global warming reaches 2°C, and even higher at 3°C.

Under a 3°C warming scenario, the number of days experiencing severe and extreme heatwaves could rise by an additional 14 days annually, significantly worsening health risks.

Australia's climate risk assessment predicts an increase from four to 18 days of severe to extreme heatwaves per year if global temperatures rise by 3°C, with current projections indicating a 2.9°C increase this century.

Climate and health experts emphasize that heatwaves are often called a 'silent killer' because they do not leave visible scars like other disasters, yet they are the deadliest form of extreme weather in Australia.

Vulnerable populations, including the elderly, disabled, and those with lower income or less education, face higher mortality risks during heatwaves, with Queensland and New South Wales experiencing over three times higher death rates than Western Australia.

Communities in rural and remote areas, especially with higher proportions of vulnerable groups, experience greater heat-related mortality, with Queensland, New South Wales, and the Northern Territory showing the highest death rates.

Despite its wealth, Australia remains highly vulnerable to climate extremes, exemplified by a severe heatwave in 2018–2019 that lasted over two months and underscoring the ongoing risks.

Research from Monash University found that between 2016 and 2019, heatwaves caused 1,009 deaths in Australia, marking a significant increase since 1900 when total heat-related deaths reached 4,555.

Health services are seeing more heat-related illnesses, including exacerbations of existing conditions, mental health issues, and gender-based violence during heatwaves, disproportionately affecting vulnerable populations.

A comprehensive analysis of over 249,000 death records revealed that heatwaves are responsible for an average of 1.08 deaths per 100,000 residents annually, mainly due to cardiovascular and respiratory diseases.

The climate has already warmed by 1.2°C above pre-industrial levels, leading to more frequent and intense heatwaves, including a record-breaking temperature of 46.6°C in Adelaide during the 2018–2019 summer.

Looking ahead, sea level rise could threaten 1.5 million Australians with coastal flooding by 2050, adding to the climate-related risks facing the country.