Deadly heat stress to become commonplace across South Asia already at 1.5°C of global warming
This report presents how South Asia is one of those hotspots where earliest exposure to deadly wet‐bulb temperatures (Tw >35°C) is projected in warmer future climates. It finds that even today parts of South Asia experience the upper limits of labor productivity (Tw >32°C) or human survivability (Tw >35°C), indicating that previous estimates for future exposure to Tw‐based extremes may be conservative.
The results show that at 2°C global warming above pre‐industrial levels, the per person exposure approximately increases by 2.2(2.7) folds for unsafe labor (lethal) threshold compared to the 2006–2015 reference period. Limiting warming to 1.5°C would avoid about half that impact. The population growth under the middle‐of‐the‐road socioeconomic pathway could further increases these exposures by a factor of ∼2 by the mid‐century. These results indicate an imminent need for adaptation measures, while highlighting the importance of stringent Paris‐compatible mitigation actions for limiting future emergence of such conditions in South Asia.