Warming: Regions soon to be uninhabitable

NASA is not sounding the alarm but is observing. And above all relays a study published in the journal “Science Advances», study which establishes that several regions of the globe could be uninhabitable by 2050. That is to say in a little over twenty years, which is really very close. The cause, we let you guess, is global warming, which is not a mirage caused by heat but a reality whose first consequences are beginning to be felt.

This study relies on what is called heat stress. In other words, the stress that the body experiences when subjected to very hot environments increases its internal temperature. It should not be neglected, especially in the workplace, and every year, people die from heat stroke caused by this thermal stress. It is currently the main cause of death linked to global warming. In the case of our study, two factors were taken into account. The heat index, which combines ambient air temperature and relative humidity. And the wet bulb temperature index, which takes into account solar radiation. This globe thermometer was designed in 1956 by the Marines to reduce the risk of heat stress injuries in new recruits. Like the military, athletes also use it. In the case that interests us, it makes it possible to measure the lowest temperature to which an object can cool when humidity evaporates from it.

Heat dissipation

Scientists therefore combined these two indicators. Two scenarios then arise. If it is hot but the air is not humid, our body will be able to cool itself through perspiration, which reduces body temperature by releasing heat at the skin level. But if the ambient air is, on the contrary, too humid, the body will have much more difficulty in evacuating additional humidity, that is to say, in sweating, and therefore in cooling itself. In summary, if the ambient temperature is high but the wet bulb temperature is low, our body will be able to release heat by sweating. But if the wet bulb temperature is high, then our body’s ability to cool itself will be less effective. “This triggers changes in the body,” explains NASA. You become dehydrated. Your organs are under stress, especially your heart. Blood rushes to your skin to try to release heat, deserting your internal organs. The consequences can be fatal.” And if the wet-bulb temperature exceeds 35°C, “no amount of sweating or other adaptive behavior will be enough to bring the body back to a safe operating temperature,” warns Colin Raymond, a researcher at California Institute of Technology and lead author of the study.

The question now is whether such temperatures have ever been observed. The answer is yes. Between 1979 and 2017, in several regions of the globe, and rather in subtropical zones, which is not surprising. Occasional phenomena, such as the coastal current El Niño, can further increase this relative temperature. Mexico, Iran, India and Pakistan were notably concerned. In addition, the researchers also specify that the risk of death is present even with indices lower than that of 35°C. By the end of this century, periods of extreme heat will increase fourfold. Another notable fact, since 1991, heat has caused the direct death of 143 people per year, it is estimated.

American states in danger

Data yet unrelated to NASA’s predictions or forecasts. Which incriminates more territories than those mentioned above. Among these uninhabitable geographic areas will be South Asia, the Persian Gulf and the Red Sea. As well as eastern China, parts of Southeast Asia and Brazil, the latter by 2070. Several American states could also be affected, such as Arkansas, Iowa or Missouri. And that’s more unusual. In other words, the phenomenon tends to get closer. European areas are not currently affected. We can still sleep peacefully on this side of the globe for a few decades.

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