Deadly heat waves projected in the densely populated agricultural regions of South Asia

Abstract
The risk associated with any climate change impact reflects intensity of natural hazard and level of human vulnerability. Previous work has shown that a wet-bulb temperature of 35°C can be considered an upper limit on human survivability. On the basis of an ensemble of high-resolution climate change simulations, we project that extremes of wet-bulb temperature in South Asia are likely to approach and, in a few locations, exceed this critical threshold by the late 21st century under the business-as-usual scenario of future greenhouse gas emissions. The most intense hazard from extreme future heat waves is concentrated around densely populated agricultural regions of the Ganges and Indus river basins. Climate change, without mitigation, presents a serious and unique risk in South Asia, a region inhabited by about one-fifth of the global human population, due to an unprecedented combination of severe natural hazard and acute vulnerability.

Deadly Heat Is Forecast in Persian Gulf by 2100

By the end of this century, areas of the Persian Gulf could be hit by waves of heat and humidity so severe that simply being outside for several hours could threaten human life, according to a study published Monday. Because of humanity’s contribution to climate change, the authors wrote, some population centers in the Middle East “are likely to experience temperature levels that are intolerable to humans.”

The dangerously muggy summer conditions predicted for places near the warm waters of the gulf could overwhelm the ability of the human body to reduce its temperature through sweating and ventilation. That threatens anyone without air-conditioning, including the poor, but also those who work outdoors in professions like agriculture and construction.

The paper, published in the journal Nature Climate Change, was written by Jeremy S. Pal of the department of civil engineering and environmental science at Loyola Marymount University in Los Angeles and Elfatih A. B. Eltahir of the Massachusetts Institute of Technology. Previous studies had suggested that such conditions might be reached within 200 years. But the new research, which depends on climate models that focus on regional topography and conditions, foresees a shorter timeline.