Extreme Temperature Diary- Sunday November 5th, 2023/Main Topic: Another Study Warning That Climate Driven Heat May Make Some Parts of Our World Uninhabitable – Guy On Climate
The ambient wet-bulb temperature limit for young, healthy people is about 31 C, which is equal to 87.8 F at 100% humidity. However, in addition to temperature and humidity, the threshold for any individual at a specific moment also depends on their exertion level and environmental factors, including wind speed and solar radiation. In human history, temperatures and humidity that exceed human limits have been recorded only a limited number of times — and only for a few hours at a time — in the Middle East and Southeast Asia, according to the researchers.
Results of the study indicate that if global temperatures increase by 2 C above pre-industrial levels, the 2.2 billion residents of Pakistan and India’s Indus River Valley, the one billion people living in eastern China and the 800 million residents of sub-Saharan Africa will annually experience many hours of heat surpassing human tolerance.
 Map showing annual hot-hours over South Asia (A–D), East Asia (E–H), North Africa (I–L), Middle East (M–P), and North America (Q–T) under 1.5, 2, 3, and 4 °C of warming relative to preindustrial level. Graphic: Vecellio, et al., 2023 / PNAS |
