- Steven Reinberg
- Posted March 24, 2020
High Heat, Humidity Could Affect More Than 1.2 Billion People by End of Century
As the Earth continues to warm from climate change, an estimated 1.2 billion people will be affected by heat stress from extreme heat and humidity by 2100, a new study predicts.
That is four times more people than are affected today and over 12 times more than would have been affected if climate change hadn't happened, researchers say.
"When we look at the risks of a warmer planet, we need to pay particular attention to combined extremes of heat and humidity, which are especially dangerous to human health," senior author Robert Kopp said in a Rutgers University news release. He is a professor and director of the Rutgers Institute of Earth, Ocean and Atmospheric Sciences in New Brunswick, N.J.
Heat stress occurs when the body can't cool down properly through sweating. When body temperature rises quickly, the brain and other organs can suffer damage. Heat stress can cause heat rash and heat cramps or heat exhaustion. But heat stroke can be deadly.
For the study, researchers modeled various climate simulations.
They found that if the planet warms by 3 degrees Fahrenheit, extreme heat and humidity could affect places where about 500 million people live today. If temperatures rose 4 degrees Fahrenheit, nearly 800 million people would be affected.
The planet has already warmed 2 degrees Fahrenheit above levels from the late-19th century, the researchers noted.
An estimated 1.2 billion people would be affected if the Earth warmed by 5 degrees Fahrenheit, which is expected by the end of the century.
"Every bit of global warming makes hot, humid days more frequent and intense. In New York City, for example, the hottest, most humid day in a typical year already occurs about 11 times more frequently than it would have in the 19th century," said lead author Dawei Li, from the University of Massachusetts Amherst.
The report was published recently in the journal Environmental Research Letters.
For more on heat stress, head to the U.S. Centers for Disease Control and Prevention.
SOURCE: Rutgers University, news release, March 12, 2020