The Uninhabitable Earth: Life After Warming

by David Wallace-Wells

At eleven or twelve degrees Celsius of warming, more than half the world’s population, as distributed today, would die of direct heat. Things almost certainly won’t get that hot, any time at all soon, though some models of unabated emissions do bring us that far eventually, over centuries. But at just five degrees, according to some calculations, whole parts of the globe would be literally unsurvivable for humans. At six, summer labor of any kind would become impossible in the lower Mississippi Valley, and everybody in the United States east of the Rockies would suffer more from heat than anyone, anywhere, in the world today. New York City would be hotter than present-day Bahrain, one of the planet’s hottest spots, and the temperature in Bahrain “would induce hyperthermia in even sleeping humans.” Five or six degrees is unlikely by 2100. But at just two degrees, cities now home to millions, across India and the Middle East, would become so hot that stepping outside in summer would be a lethal risk, and wildfires already terrifying anyone living in the American West would burn at least four times as much land. The sea level rise made inevitable by that amount of warming would, over centuries, flood or drown hundreds of major cities.