Should carbon emissions and global warming continue to rise unabated, parts of the Persian Gulf region could be hit with "unprecedented events of deadly heat" within this century, according to new research published Monday in the journal Nature Climate Change.
"Our results expose a specific regional hotspot where climate change, in the absence of significant mitigation, is likely to severely impact human habitability in the future," write study co-authors Elfatih Eltahir, a professor of civil and environmental engineering at Massachusetts Institute of Technology (MIT) and MIT alumnus Jeremy Pal, now a professor at Loyola Marymount University.
Running high-resolution versions of standard climate models, Eltahir and Pal found that many major cities in the Middle East "could exceed a tipping point for human survival, even in shaded and well-ventilated spaces," according to a press statement from MIT.
That tipping point involves a measurement known as "wet-bulb temperature." As the MIT release explains, a human body may be able to adapt to extremes of "dry-bulb temperature" (commonly referred to as simply temperature) through perspiration and associated evaporative cooling—provided that the wet-bulb temperature (a combined measure of temperature and humidity or degree of 'mugginess') remains below a threshold of 35°C.
Eltahir says this threshold "has, as far as we know … never been reported for any location on Earth."
But it got close this summer in Bandar-e Mahshahr, Iran, where the wet-bulb temperature hit 34.6°C—or a heat index of 165°F—in July. And such an event could occur several times in a 30-year period toward the end of the century under the business-as-usual scenario used as a benchmark by the Intergovernmental Panel on Climate Change, the researchers warn.
The Persian Gulf region is especially vulnerable, the researchers say, because of a combination of low elevations, clear sky, an adjacent water body that increases heat absorption, and the shallowness of the Persian Gulf itself, which produces high water temperatures that lead to strong evaporation and very high humidity.
Learn more in this video from MIT:
Despite all this, the Guardian reports, "[o]il and gas rich nations in the region, particularly Saudi Arabia, have frequently tried to frustrate international climate change negotiations. The Gulf, where populations are rising quickly, was hit in 2015 by one of its worst-ever heatwaves...and led to a significant number of deaths."
Air conditioning might be able to protect people indoors and those in wealthy Gulf oil states might be able to afford it, said the scientists, but less wealthy nations like Yemen would suffer. "Under such conditions, climate change would possibly lead to premature death of the weakest—namely children and the elderly," they said.
And as the Guardian noted in separate reporting on Monday, over-reliance on air conditioning and refrigeration comes with its own set of negative implications. "[S]ince cold is still overwhelmingly produced by burning fossil fuels," wrote reporter Jon Henley, "emission targets agreed at next month’s international climate summit in Paris risk being blown away as governments and scientists struggle with a cruel climate-change irony: cooling makes the planet hotter."