Wet-Bulb Temperatures and the Emerging Geography of Unsurvivable Heat
No site analysed reaches the 35 °C wet-bulb ceiling before about 4.4 °C of global warming; the binding line is lower. Healthy young adults lose the ability to cool themselves in humid heat near 30.5 °C, a level 11 of 161 sites reached for at least an hour in 2024. Under current policies, about 2.8 °C, the cities touching it would hold 161 million people, up from 9 million today — around the Gulf, across South Asia and in eastern China.