More recently, scientists said that the establishment of a hot and humid climate in the tropics and subtropics will occur with the planet warming up only by the end of this century. But new data suggests that these changes have already begun, and at once on all continents.
According to a study by scientists from Columbia University in the USA, unprecedented heat and humidity are already becoming a reality in many places in Asia, Africa, Australia, South and North America, including the Gulf Coast. Several brief outbreaks have been recorded along the Persian Gulf, exceeding the theoretical threshold for human survival. While such cases occur in a limited area and last several hours, but their frequency and intensity are growing, writes Phys.org. And this is happening in direct accordance with global warming.
Humidity is believed to be dangerous to humans because it makes it difficult for the body to cool naturally through sweat. Dry hot air evaporates moisture from the body, lowering its temperature, but if the air is already humid, then evaporation slows down and may even stop. In this case, the body heats up above the survival threshold, and the internal organs begin to fail. Even a physically prepared person, being in the shade and having enough drinking water at his disposal, can die in a few hours.
When they first analyzed hourly data from weather stations from 1979 to 2017, the researchers found that the combination of high temperature and humidity doubled over the study period. And potentially fatal indicators were recorded in three cities of Saudi Arabia, Qatar and the United Arab Emirates - Damman, Doha and Ras Al Khaimah, whose population is more than 3 million people.
Incidents mainly occur on the banks of rivers, lakes or bays, where evaporation increases air humidity. In some regions located inland, moisture is brought by monsoons or irrigation canals. Poor countries are most at risk, where residents do not have not only air conditioners, but also electricity, and to maintain life, they are forced to work in the open. The rise in cases of unbearable heat will sooner or later destroy their economies.
Climatologists at the Australian University of New South Wales say many areas of the Earth are much closer than expected to achieve sustained unbearable heat. Previously it was believed that we have a much larger margin of safety.
Recall that 2019 has become one of the warmest in human history. July turned out to be especially hot, when the average temperature of the planet was 0.95 ° C higher than the average temperature for the entire XX century. And it looks like extreme weather is becoming the new normal.