Inland from Bondi Beach, ‘Heat Islands’ make summer deadlier in Australia
The construction site was just 15 miles inland from Bondi Beach on Australia’s east coast, but it might as well have been a world away. When the first heat wave of the summer hit earlier this month, the sweltering conditions left the Apenisa Marau colleague too delirious to function, with a pounding head and sore, sore eyes. He was moved to a cool corner to rest and hydrate.
The western expanse of Sydney, the country’s largest city, has always been warmer than its coastal suburbs due to geography. A cooling sea breeze does not reach these low-lying plains, where less rain falls than in the east.
But in recent decades, rapid urban development has made the region even hotter. It is now peppered with so-called heat islands: dense and populated neighborhoods that trap heat and magnify the effects of a warming planet. Temperatures can be as much as 18 degrees Fahrenheit (10 degrees Celsius) higher than in Eastern Sydney.
Heat waves cause more deaths worldwide than all other natural disasters combined. In Australia, the hot and dry El Niño weather pattern has returned after more than half a decade, making summer a highlight acute danger for the millions of people who live in Western Sydney.
Mr Marau, 28, moved to Australia from Fiji in early 2022 to escape cyclones, floods and rising seas on his home island of Vatulele.
“When I came to Australia I thought we wouldn’t have to deal with any of these things. But I didn’t know about these heat waves,” he said. “It’s quite scary, it’s inescapable.”
Western Sydney has one of these fastest growing urban population in the country, mainly fueled by international migration. Cheaper homes are a big draw: average property prices can be on the rise three times less then in the city center. As the area’s population has grown to around 2.5 million – almost one in ten Australians now live in Western Sydney – so has its urban development. The number of green spaces is decreasing, while the number of artificial surfaces, such as bitumen and concrete, that absorb and radiate heat is increasing.
Some researchers warn that if the Earth continues to warm at a rapid pace, the number of days of extreme heat, with temperatures higher than 35 degrees Fahrenheit, will increase fivefold to 46 by 2090.
Mr Marau lives in the suburb of Cabramatta and shares a three-bedroom house with eight people to save money on energy bills. Other Western Sydney residents hang duvets over windows to block out sunlight, or spend entire days in air-conditioned malls, says Aquilina Pinto, a community worker who has lived in the Mount Druitt suburb for 40 years and whose family has been affected by extreme temperatures. Her uncle died of heatstroke while washing his car.
This summer she fears the worst.
“There will definitely be more deaths,” she says. “We suffer.”
Despite calls for governments and developers to adopt more climate-conscious building practices, heat islands are expanding rather than shrinking, says Sebastian Pfautsch, associate professor of urban planning at Western Sydney University.
“What we’re doing is bringing hundreds of thousands of people into an area where we can expect extreme heat stress to increase,” he said. “It’s a very scary situation.”
A spokesperson for the New South Wales Planning and Environment Department, a state-level authority, said it aims to increase tree cover in Sydney by 2036, prioritizing the hottest parts of the west. The department has also introduced more energy-efficient building standards for new homes.
At the University of Sydney, Ollie Jay, who calls heat a “silent killer”, has spent years trying to understand how to mitigate the effects of extreme temperatures. Using a sealed ‘climate chamber’ in his research laboratory, he and a team of researchers simulate heat waves to study the physiological effects of heat on the human body – and the point at which they become harmful or even fatal.
Some experts say heat-related deaths in Australia have dramatically underreported. Deaths are usually accompanied by one of three complications: heat stroke, heart attack or kidney failure, conditions that are listed as causes on death certificates.
Another recent study, in which Dr. Jay was involved, it turned out that humans’ ability to survive extreme temperatures is probably vastly overestimated. This is particularly concerning for those in the heat islands of Western Sydney, who are at greater risk due to their predominantly lower socio-economic status.
“We are the most poorly resourced area in Sydney,” said Lai Heng Foong, an emergency physician at a Bankstown hospital and chair of the Medical Staff Council of New South Wales. “I don’t think we’re prepared,” she said, adding that local hospitals are already overwhelmed.
Part of the problem, Dr Lai Heng said, is that governments and communities take the dangers of heat seriously. Compared to raging wildfires and rising floods, she said, heat is undramatic, invisible and “insidious,” an “out of sight, out of mind” type of disaster.
“The one thing that emphasizes to me is that this is completely preventable,” she said. “We know it’s going to happen, and people just think we can get away with it. But we can’t do that.”