New York: Extreme heat waves with conditions “intolerable to humans" may become a regular occurrence in the Persian Gulf by century’s end, according to a study evaluating the consequences of unchecked global warming.

Temperature and humidity levels exceeding anything previously recorded on earth may bake major cities including Abu Dhabi, Dubai, Doha and Dharhan, according to the research published in the journal Nature Climate Change. Less severe but still “extremely dangerous" heat waves, now seen once every 20 years or so, would become “the normal summer day," said Elfatih Eltahir, an engineering professor at the Massachusetts Institute of Technology who co-authored the paper.

“What we are talking about is significantly more severe than people have experienced anywhere before," Eltahir said in a conference call with reporters. The most extreme conditions “would exceed what a human body may be able to tolerate."

The research studied what scientists call “wet bulb temperature," a measure that combines heat and humidity. Above a wet-bulb temperature of 35 degrees Celsius (95 degrees Fahrenheit), humans can no longer regulate their body temperature through sweating or radiating heat. That never- before observed level would correspond to a heat index — what the conditions actually “feel" like — of about 170 degrees Fahrenheit.

Heat wave

For comparison, the heat index reached 163 degrees in Iran in July during a record heat wave that gripped the Middle East.

Eltahir and co-author Jeremy Pal of Loyola Marymount University ran computer simulations of what the Persian Gulf’s climate may look like in the last 30 years of the century. They assumed greenhouse gases would continue to accumulate in the atmosphere at their current pace, driving up global temperatures. The modeling found major coastal cities would surpass the 35-degree wet-bulb mark about once a decade and peak just below that level even more frequently.

The Hajj, the annual pilgrimage that draws millions of Muslims to Mecca in Saudi Arabia, could “become hazardous to human health" when it occurs during the summer, especially for elderly travelers, the study said. Standard temperatures in the city are projected to exceed 55 degrees Celsius. In Kuwait City, the researchers found, the annual peak could reach 60 degrees.

The results show Persian Gulf countries have an interest in reining in climate change, the authors said, even with their economies tied to oil and gas industries that are a prime source of greenhouse gases.

“Although it may be feasible to adapt indoor activities in the rich oil countries of the region, even the most basic outdoor activities are likely to be severely impacted," the authors wrote. Less wealthy, oil-poor areas like coastal Yemen “will probably suffer both indoors and outdoors." Bloomberg