Climate change could see up to 1.2 BILLION people suffer from unsafe temperatures by 2100
Rising temperatures caused by could see up to 1.2 billion people suffer from heat stress by 2100 if greenhouse gases are not curbed, a study found. Researcher from Rutgers University in New Jersey found that four times as many people could end up being impacted by heat stress than are today. Heat stress harms human and animal health, agriculture, the economy and the environment. Heat stress in humans is caused when the one is unable to cool down adequately by means of sweating leading the body's temperature to rise dangerously. Previous studies into projected future climates and heat stress have typically focused on heat extremes, but overlooked another key driver humidity. '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,' explained climate scientist Robert Kopp of Rutgers University. 'Every bit of global warming makes hot, humid days more frequent and intense,' said paper author Dawei Li, who now works at the University of Massachusetts. '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.' In their study, the researchers used 40 different climate simulations to examine how combined extremes of heat and humidity would occur on a warming Earth. The team used a measure of heat stress that considered various individual factors including temperature, humidity, wind speed and both solar and infrared radiation. The models suggest that that areas currently home to some 500 million people would be subjected to extreme heat and humidity in excess of safe levels each year if the planet warms by the Paris Climate target of just 1.5C (2.7F). This would increase to 800 million people under 2C (3.6F) of warming above pre-industrial levels and up to around 1.2 billion people should the planet warm by 3C (5.4F) an increase expected under a 'business as usual' policy scenario. The planet has already warmed by about 1.2C (2.2F) since the late 19th century. Heat stress in humans is caused when the one is unable to cool down adequately by means of sweating leading the body's temperature to rise rapidly, which can ultimately damage the brain and other organs. Its most severe form, heat stroke, can kill or cause permanent disability if emergency treatment is not administered, the US Centers for Disease Control and Prevention have warned. The most common manifestation of heat stress is heat exhaustion, however, with other milder conditions including heat rash and heat cramps. The full findings of the study were published in the journal .