Boiled frog syndrome says that if a frog is suddenly placed in boiling water it will jump, but if it is placed in warm water, and then slowly heated, it will not perceive the danger and will be cooked to death. Experiments from the 19th century affirmed this, but experiments from the 20th century denied it. Now, in the 21st century, climate change will test it in humans. A study that has just been published by the American scientific journal Proceedings of the National Academy of Sciences indicates that 4,000 million inhabitants would be one step away from jumping out of the pot.
If global warming goes beyond 1.5 degrees above pre-industrial levels, the combination of heat and humidity will have “devastating” consequences for human health. Just half a degree above that increase that, in 2015, 196 nations pledged not to exceed in the Paris Agreement, and the 2.2 billion residents of Pakistan and India’s Indus River Valley, the billion people who live in eastern China, and the 800 million of sub-Saharan Africa, that is, Almost half of the world’s population would be subjected to waves of heat and humidity so extreme that it would “exceed human tolerance.”
What is worrying, the researchers point out, is that these regions are also in low and middle income countries, Therefore, many of those affected will not have access to air conditioning or any other effective way to mitigate the negative effects of heat.
The ambient temperature limit for young, healthy people is approximately 31 degrees with 100% humidity, according to work published last year by researchers at Pennsylvania State University. In human history, the researchers point out, temperatures and humidity that exceed human limits have been recorded only a limited number of times, and for a few hours at a time in the Middle East and Southeast Asia.
The team of researchers modeled global temperature increases between the 1.5 degrees of the Paris Agreement and 4 degrees, which is the worst scenario proposed by climate experts. Researchers believe a 3-degree rise is the best estimate of how much the planet will warm by 2100 if no action is taken. If global warming were put at that number, then human tolerance would also be exceeded on the east coast and central United States, as well as South America and Australia.