Experts are in a state of alert after Australia has seen century-old heatwave records completely shattered during the past months.
Hobart alone had a November run of six consecutive days above 26 degrees, a phenomenon not witnessed in 130 years.
Sydney, on the other hand, saw seven consecutive days in November with maximum temperatures equal or above 25 degrees. This hasn’t happened at all since 1968 and has only occurred in two Novembers in the last 118 years.
Climate scientists are warning that if these conditions persist, a number of Australia’s capitals will become uninhabitable in the very near future.
Heatwaves form when high pressure in the upper atmosphere stops air from rising and traps the heat, similarly to how a pressure cooker works. Extreme heatwaves wreak havoc on the environment and threaten power, traffic and water infrastructure.
Unsurprisingly, heatwaves have greater fatality rates worldwide than avalanches and earthquakes. In Australia, they’re responsible for 55% of all natural disaster-related deaths.
Scientists say that without major reductions in emissions of greenhouse gases, it’s believed that up to three in four people will face the threat of dying from heat by 2100.
In addition to the “pressure cooker effect”, local circumstances make the situation even more dire in places like Darwin.
The city’s extensive use of bitumen, a black viscous mixture of hydrocarbons commonly used for road surfacing and roofing, causes surface temperatures to skyrocket.
Chief Minister Michael Gunner said “The study found our (Darwin’s) streets, parking lots, roofs and pavements have very high surface temperatures, ranging from 45-67C.”
“Areas such as the Post Office carpark, the Supreme Court car park, and the Bus Terminal are incredibly hot — Cavenagh Street (a CBD thoroughfare) is a river of fire.”
Combined with climate change, things look pretty grim indeed.
Mattheos Santamouris, a professor of high performance architecture at the University of NSW, is working on the project and said Darwin is a typical case of “urban heat island” effect, where the materials used in buildings and roads boost temperatures to dangerous levels.
“In Darwin, you have overheating because there’s too much bitumen and not enough greenery,” he said.
“A material with a temperature of about 70C may heat the air by around 3C.”
There are initiatives local officials can take to mitigate overheating, such as adopting alternative construction materials and creating large “green zones” amidst urban areas, but all of these measures can only go so far if climate change isn’t addressed at a global scale.
“As it keeps warming and warming, there’s only a little it can do,” says climate change expert Dr Elizabeth Hanna from Australian National University.
“Global temperatures are going so badly and emissions are increasing so much that it’s not looking good.”