Within this century, parts of the Persian
Gulf1 region could be hit with
unprecedented2 events of deadly heat as a result of climate change, according to a study of high-resolution climate models. The research reveals details of a business-as-usual
scenario3 for greenhouse gas
emissions4, but also shows that
curbing5 emissions could
forestall6 these deadly temperature extremes.
The study, published today in the journal Nature Climate Change, was carried out by Elfatih Eltahir, a professor of civil and environmental engineering at MIT, and Jeremy
Pal7 PhD '01 at Loyola Marymount University. They conclude that conditions in the Persian Gulf region, including its shallow water and intense sun, make it "a specific regional hotspot where climate change, in absence of significant mitigation, is likely to
severely8 impact human habitability in the future."
Running high-resolution versions of standard climate models, Eltahir and Pal found that many major cities in the region could exceed a tipping point for human survival, even in shaded and well-ventilated spaces. Eltahir says this threshold "has, as far as we know ... never been reported for any location on Earth."
That tipping point involves a measurement called the "wet-bulb temperature" that combines temperature and humidity, reflecting conditions the human body could maintain without artificial cooling. That threshold for survival for more than six unprotected hours is 35 degrees
Celsius9, or about 95 degrees
Fahrenheit10, according to recently published research. (The equivalent number in the National Weather Service's more commonly used "heat index" would be about 165 F.)
This limit was almost reached this summer, at the end of an extreme, weeklong heat wave in the region: On July 31, the wet-bulb temperature in Bandahr Mashrahr, Iran, hit 34.6 C -- just a fraction below the threshold, for an hour or less.