GEOGRAPHY IN THE NEWS:

Because warmer air can hold more moisture, humidity is expected to rise along with global temperatures. A recent study published in Nature Geoscience suggests that the combination could push human life in the tropics to the breaking point. "Humans’ ability to regulate their body heat is dependent upon the temperature and humidity of the surrounding air. We have a core body temperature that stays relatively stable at 37C (98.6F), while our skin is cooler to allow heat to flow away from the inner body. But should the wet-bulb temperature – a measure of air temperature and humidity – pass 35C, high skin temperature means the body is unable to cool itself, with potentially deadly consequences. ... The research team looked at various historical data and simulations to determine how wet-bulb temperature extremes will change as the planet continues to heat up, discovering that these extremes in the tropics increase at around the same rate as the tropical mean temperature. ... This has potentially dire implications for a huge swathe of humanity. Around 40% of the world’s population currently lives in tropical countries, with this proportion set to expand to half of the global population by 2050 due to the large proportion of young people in region. The Princeton research was centered on latitudes found between 20 degrees north, a line that cuts through Mexico, Libya and India, to 20 degrees south, which goes through Brazil, Madagascar and the northern reaches of Australia. ... '“Theoretically no human can tolerate a wet bulb temperature of above 35C, no matter how much water they have to drink,' [Boise State climate risk expert Mojtaba Sadegh] added."
www.theguardian.com/science/2021/mar/08/global-heating-tropical-regions-human-livability