Unbearably hot temperatures are already testing the limits of human survival and will continue to rise, challenging the ability of our bodies to cope and making parts of the world increasingly uninhabitable.
Scientists say urgent steps are needed for humans to adapt to extreme heat, such as rethinking the way we live, work, and exploit AC.
“Extreme heat will be more problematic in the future,” said Professor Blair Feltmate, head of the Intact Center for Climate Adaptation at the University of Waterloo in Ontario.
India and Pakistan have recently seen temperatures rise to 50 ° C, killing at least 90 people and devastating crops. South Asia, along with Africa, Australia, and the U.S. Gulf States, now face potentially fatal combinations of heat and humidity, conditions that scientists had not predicted until the end of this century.
Children cool off under a running water pipe on a hot summer day in New Delhi, India on May 17th. India and Pakistan recently experienced a heat wave with temperatures above 50 C. (Anushree Fadnavis / Reuters)
Canada is also suffering from the effects of extreme heat: in British Columbia last summer, 595 people died from the heat. The town of Lytton, BC, set a new Canadian heat record (49.6 C) on June 29, before being ravaged by a forest fire the next day. The same “heat dome” left the ground dry, contributing to catastrophic flooding in BC months later.
Feltmate is the author of a recent report warning of a “potentially lethal future” for Canadians in terms of heat, especially those living in the southern interior of BC, along the U.S. border in the Prades and in southern Ontario and Quebec.
“We’re going to see extreme heat events that will make what we saw in British Columbia last year during the heat dome look relatively smooth,” Feltmate said.
How heat affects our bodies
When you are exposed to prolonged heat, you may feel sluggish because your organs work harder to keep you fresh and alive.
Your heart beats harder to push blood to your skin, where it can cool down. Sweating is also essential to cool the body, but it becomes more difficult as the humidity increases.
In extreme cases of heat stroke, the body essentially begins to cook, breaking down the cells and causing damage to the organs.
A man skates in Toronto amidst a heat warning for the Greater Toronto Area and much of southern Ontario on August 22, 2021. People are generally advised to avoid strenuous activities in Toronto. outdoors during extreme heat. (Evan Mitsui / CBC)
“It’s a lot like cooking an egg,” said Professor Stephen Cheung, an expert on environmental stress in human physiology at Brock University in St. Louis. Catharines, Ont.
“The reason it goes from a liquid to a solid white mass is because the proteins have changed … If your body keeps warming up and not being able to control its temperature, eventually your proteins will do the same to your cells. “
It is not enough to sit in the shade and drink water when you are already suffering from a heat stroke. “It simply came to our notice then [an overheating person] go down as quickly as possible, ideally immersing them in water as cold as possible, ”Cheung said.
Having too much heat when going to bed also makes it difficult for us to sleep, which can lead to poor decision-making and injury, and have a detrimental impact on people’s mental health, says Michael Brauer, a professor at population school of the University of British Columbia. and public health.
A woman carries a pedestal fan during the humid and hot weather in Karachi, Pakistan, on May 11th. (Akhtar Soomro / Reuters)
“Nighttime temperatures matter a lot. We’re really trying to make your bedroom cool enough, to keep your body cool enough so you can sleep.”
Beat the heat
For anyone who assumes he can train his body to withstand the heat, Cheung, who helped Canadian athletes prepare for the heat and humidity of last year’s Tokyo Olympics, he says it is possible to some extent. The central temperature of our body can be adjusted to a higher heat for a period of about two weeks of gradual and continuous exposure.
But “in terms of global warming, it’s a band-aid solution.”
“The biggest advantage, in a sense, we humans have over other animals is our behavior: that we can develop things like housing, air conditioning, better clothes, and so on,” Cheung said. “But that comes at a cost, whether it’s to keep us indoors or to increase the energy use of the air conditioner.”
Many people can’t stay indoors and stay cool, including those who work hard outdoors, such as farmers and manual laborers.
There are concerns for outdoor workers, including farm workers, as temperatures continue to rise. In this photo, workers from Mexico and Guatemala pick strawberries on a farm in Pont Rouge, Que., On August 24, 2021. (Jacques Boissinot / The Canadian Press)
In the future, Feltmate says, the day will have to be changed so that these workers can avoid the hottest part of the day, for example, starting work at 5.30am and ending at 1pm.
Cities themselves need to be cooled, and that involves designing and adapting buildings thinking about the heat, planting more trees, and painting the roofs white to reflect light instead of absorbing it, Feltmate says.
He also says it is crucial that residential buildings have a safe power supply to ensure that air conditioning and fans continue to operate if there is a heat-induced shutdown.
Lack of urgency
As simple as these measures may seem, Feltmate says Canadian cities and governments are not moving fast enough, despite warnings about the potential for devastating loss of life due to extreme heat.
“What is missing from the equation, more than anything, is the lack of appreciation of the need to act urgently to implement adaptation measures.”
A man trotted with his dog during the thick morning fog in Dubai, UAE, on February 13, 2021. Scientists warn that the UAE and other Persian Gulf states will end up getting too hot for humans to the outdoors. (Kamran Jebreili / The Associated Press)
Adapting also means developing a plan for when places really get too hot for human habitability, as is expected in parts of the Persian Gulf, South Asia, Central America, and West Africa before the end of century.
“There are real thresholds that our bodies can reach even when you are acclimatized, and the Gulf region is beginning to exceed those thresholds more regularly,” said Cascade Tuholske, a researcher at the International Network Information Center. Columbia University Earth Sciences, whose research focuses. to exposure to deadly urban heat.
The poorest countries where people depend on subsistence agriculture could see mass migration to cities, which themselves are ill-equipped to cope with rising heat.
That’s why global solutions to climate change are so important, Tuholske said.
“I really question the habitability of many of the most populous places on the planet because of the extreme heat without adaptation. The future really depends on the present and how much we mitigate the heat now.”