Australia’s summer officially begins on December 1, but climate change observes no calendar. And even as another summer is almost upon us, memories of last summer’s ferocious fires still linger on the minds of those devastated by all manner of loss.
For weeks on end, the residents of many towns and cities not directly threatened were almost asphyxiated by smoke from firestorms driven by multi-day heat waves that are occurring more frequently and are getting hotter and lasting longer by the day—globally.
And in keeping with a long-established norm, some prominent politicians propagated misinformation, suggesting that the majority of fires were either lit by arsonists, the result of poor land management, or not historically unusual. Scientists dismiss these claims.
Hot days and hellish nights
Since the 1950s, extreme fire weather and the length of the fire season across large parts of Australia have increased in concert with a changing climate.
The empirical data tells us that Australia’s climate has warmed by around 1.44°C (± 0.24) since records began in 1910. Last year was Australia’s hottest and driest year ever recorded with a national mean surface temperature of 1.88°C warmer than average.
Heatwaves are now more common than ever. Combined with extended periods of drought, heatwaves exacerbate the risk of massive firestorms. Human-induced global warming is driving the frequency of these conditions.
Heatwaves are caused by powerful high-pressure domes stationed high overhead, compacting and heating the upper atmosphere while trapping the lower atmosphere below as the scorched terrain heats the air from the ground up. The longer the high-pressure dome refuses to budge, through lack of air currents strong enough to move it along, the hotter it gets.
Heatwaves are deadly and have killed more Australians than cyclones, floods, and tropical storms combined. They are increasing in intensity, frequency, and duration. And if global warming reaches 2.0°C, it is predicted that their frequency will increase by 85 per cent. At 3.0°C, they could last as long as a month.
Welcome to the Age of Embers: or the Pyrocene as Stephen J Pyne called it
Despite assumptions that humans can adapt to a warming planet, peak heat stress suggests a forbidding upper limit wherein the body begins to shut down.
Humans start to overheat when the surrounding temperature is close to or exceeds one’s body temperature of 37 ?C, especially under conditions of dehydration. Heatstroke can occur when core body temperature rises above 40.5°C and can be fatal if not treated.
In 2003, 70,000 people in Europe died as a result of the June-August heatwave. In 2010, a 44-day heatwave caused 56,000 excess deaths in the Russian Federation.
Last year’s European summer sent temperatures skyrocketing and records tumbling. France issued an unprecedented red alert and recorded its highest temperature ever at 45.9 ?C. New highs were also established in the Czech Republic, Netherlands, Belgium, Slovakia, Austria, Andorra, Luxembourg, Poland, and Germany.
This year’s North American summer was also another scorcher with California and the San Francisco Bay area experiencing a merciless fire season that inspired a new Digital Age term: “gigafire”.
On February 9 this year, Seymour Island on the Antarctic Peninsula—once called the Rosetta Stone of Southern Hemisphere palaeobiology because it provides one of the world’s richest fossiliferous Palaeogene sequences—experienced a day never before recorded at 20.75°C. Even a one-off t-shirt-and-shorts temperature reading this high suggests things might be about to go awry.
If we fail to stop global warming, a rise of 2°C could see deadly clusters of 50°C days in our major cities like Sydney and Melbourne. And by 2100, heat death from heatwaves will threaten as much as 75 per cent of the global population.
When the birds stop singing
At 50°C the birds stop singing, parks and streets are empty, and the roads begin to melt. Animals seek shelter—including Homo urbanis—and cooling systems place a massive load on the energy grid as people fight to keep the monstrous heat at bay and prevent themselves from cooking—literally. Even the ocean feels like a jacuzzi and offers no respite.
Australia had its hottest day recorded on December 18, 2019, with a nationwide average temperature of 41.88°C, well above the previous record of 40.30°C set on January 7, 2013. To place this in perspective, the Australia-wide mean surface temperature maximum has exceeded 40°C for more days in the two previous summers than in the preceding 110 years.
The hottest December day last summer was 49.9°C recorded on December 9 at Nullarbor, a small town 1,000 kilometres north-west of Adelaide in South Australia, which was also a new December record.
Last December’s maximum temperatures were 4.15°C above average—well above the previous December record of +2.41°C set in 2018. It was also the highest above-average month in 110 years.
Vast sun-shelters on our favourite beaches
Such deviations in the climate are now the norm. But it still amazes me that people continue to sprawl themselves out under a blistering midday sun.
In the near future, as the days get hotter, to retain the reputation of a premier beach destination, coastal councils will need to erect vast sun shelters on popular beaches—at least through the summer months—to protect bathers from UV radiation that can permanently damage your DNA.
Swimmers and surfers will need to wear head-to-toe protective clothing. Councils, in their “duty of care” role, will be forced to close beaches in the hottest parts of the day. The thought of which, for myself, who grew up with the natural beauty of the beach, evokes a savage surrealism of a planet screaming out as it collapses under heat stress.
You might then wonder, will clusters of 50 °C days, or even 60 °C days, prompt Scotty the frog to jump out of the pot and take some serious climate change action before it boils, or will it remain a case of “economic growth at all costs” and we all boil together?
Dr Stephen Dark has a PhD in Climate Change Policy and Science, and has lectured at Bond University in the Faculty of Society & Design teaching Sustainable Development and Sustainability Economics. He is a member of the Urban Development Institute of Australia and the author of the book Contemplating Climate Change: Mental Models and Human Reasoning.