Extreme global temperatures are pushing the human body “close to thermal limits”, according to a climate scientist.
Record-breaking heat has swept through Europe this week with temperatures topping 40C in a number of countries.
However, in places such as South Asia and the Persian Gulf, people are already enduring temperatures reaching up to 54C.
Despite all the body's thermal efficiencies, these areas could soon be uninhabitable, according to Loughborough University climate scientist Dr Tom Matthews in The Conversation.
When air temperature exceeds 35C, the body relies on sweating to keep core temperatures at a safe level. However, when the “wet bulb” temperature – which reflects the ability of moisture to evaporate – reaches 35C, this system no longer works.
“The wet bulb temperature includes the cooling effect of water evaporating from the thermometer, and so is normally much lower than the normal (“dry bulb”) temperature reported in weather forecasts,” Dr Matthews wrote.
“Once this wet bulb temperature threshold is crossed, the air is so full of water vapour that sweat no longer evaporates,” he said.
This means the human body cannot cool itself enough to survive more than a few hours.
“Without the means to dissipate heat, our core temperature rises, irrespective of how much water we drink, how much shade we seek, or how much rest we take,” he explained.
Some areas – which are among the most densely populated on Earth – could pass this threshold by the end of the century, according to Dr Matthews.
There is already evidence wet bulb temperatures are occurring in Southwest Asia.
With climate change starting to profoundly alter weather systems, rising temperatures could soon make parts of the world uninhabitable.
If electricity can be maintained, living in chronically heat-stressed conditions may be possible but a power outage could be catastrophic.
In a recent paper published in Nature Climate Change, Dr Matthews and his team looked at the probability of a “grey swan” event in the case of extreme heat coinciding with massive blackouts.
“We found that as the climate warms, it becomes ever more likely that these powerful cyclones would be followed by dangerous heat, and that such compound hazards would be expected every year if global warming reaches 4C.
“During the emergency response to a tropical cyclone, keeping people cool would have to be as much a priority as providing clean drinking water.”
Heat-stressed countries are likely to see the largest absolute increases in humid-heat and they are often the least well-prepared to deal with the hazard. This could drive mass migration, which would make heat a worldwide issue – even for countries that are not experiencing scorching temperatures.
Dr Matthews wrote: “The challenges ahead are stark. Adaptation has its limits. We must therefore maintain our global perspective on heat and pursue a global response, slashing greenhouse gas emissions to keep to the Paris warming limits.
“In this way, we have the greatest chance of averting deadly heat – home and abroad.”
Link: Chinese Hoax me if old
I had never heard about the wet bulb temperature before.
I fear that we might see massive migrations of people leaving these hot areas. It could totally overwhelm places like western Europe as the potential for refugees over climate change is so many more times greater than with Syria. At the same time, you also wonder how much and how long these people can endure these increasing temperatures. There are billions of people living in these regions - Where are they gonna go in total desperation once it gets bad enough? You cannot really grow shit anymore.
And in places like India they have other disasters like their water draught;
“The current water crisis in Chennai was predicted years ago, and there has been relatively little effort made to prepare for it,” says Mervyn Piesse, manager of global food and water crises research program at Future Directions International, a research institute based in Nedlands, Australia.
The situation in Chennai reflects a larger water crisis spreading across India. Half the country’s population—600 million people—live in areas where water resources are highly or extremely stressed. About 100 million people living in 21 of India’s biggest cities may see their groundwater exhausted by the end of next year, according to a 2018 study by NITI Aayog, an Indian government policy think tank.
Link: WSJ Water Crsis
What would 600 million people on the run in desperation for water even look like? That sounds like a cocktail for civil war, extremism, famine and mass deaths. Really, really scary stuff. You can reflect on the corruption and incompetence of the Indian government. A lot of people could die and get hurt on their watch, and this will have a ripple effect across other nations as desperate people pour over destabilizing other vulnerable nations.