How Australia’s Extreme Heat Might Be Here To Stay
Asection of highway connecting Sydney and Melbourne started to melt. Bats fell dead from the trees, struck down by the heat.
On the northern Great Barrier Reef, 99 per cent of baby green sea turtles, a species whose sex is determined by temperature, were found to be female.
In outer suburban Sydney, the heat hit 47.3C (117F) before a cool change knocked it down - to the relative cool of just 43.6C in a neighbouring suburb the following day.
Scenes from a sci-fi novel depicting a scorched future? No, just the first days of 2018 in Australia, where summer is in fierce form. With parts of the US suffering through a particularly grim winter, extremes in both hemispheres have triggered discussions about the links between current events and the build-up of carbon dioxide in the atmosphere.
Climate change ‘no brainer’
The climate system is incredibly complex and no weather event can be directly attributed to rising emissions, but everything that is experienced today happens in a world that is about one degree warmer than the long-term mean. Prof Andy Pitman, the director of the ARC Centre of Excellence for Climate Extremes at the University of New South Wales, says given the average temperature has risen it is a “no brainer” that the likelihood of the sort of heat that hit Sydney last week has also increased.
“It was a meteorological anomaly, but the probability works a bit like if you stand at sea level and throw a ball in the air, and then gradually make your way up a mountain and throw the ball in the air again,” he says.
“The chances of the ball going higher increases dramatically. That’s what we’re doing with temperature.”
Record breaking news
While it is record-breaking that tends to make news, scientists say it is the unbroken run of hot days in the high 30s and 40s that causes the significant problems for human health, and other life.
Health officials in Victoria highlighted the threat of heatwaves when they found about 374 more people died during an extreme three-day period in January 2009 than would have been expected had it been cooler.
There has, however, been relatively little investment in research into the health impact of escalating maximum temperatures.
Paper on climate change
A paper published in the journal Nature Climate Change last year said while a government report called for greater focus on the area 25 years ago, less than 0.1 per cent of health funding since has been dedicated to the impact of climate change.
Prof Pitman says Australia is yet to properly consider the health risks of a warming planet. Last year was Australia’s thirdwarmest year since records began, according to the Australian Bureau of Meteorology.
Globally, it was the second or third warmest, and comfortably the hottest year in which there was not an El Niño weather system helping push up temperatures further.
Put another way: it is now hotter without an El Niño than it was with an El Niño just a few years ago.
People escape the heat at the iconic Bondi beach in Sydney, Australia.