The sizzling high temperatures that sent the heat index - a combination of temperature and humidity - up to 73 degrees Celsius in Iran this past summer could become the rule by the end of the century rather than the exception, according to new research.
The reason? Climate change, says a team of scientists from the Massachusetts Institute of Technology and Loyola Marymount University, writing in the journal Nature Climate Change.
The combination of intense sun and shallow waters makes the Persian Gulf area “a specific regional hotspot where climate change, in absence of significant mitigation, is likely to severely impact human habitability in the future,” the researchers wrote.
Heat could be so intense that in many regional cities, the temperature “could exceed a tipping point for human survival, even in shaded and well-ventilated spaces,” and even for healthy adults.
The tipping point means a combination of 35 degrees Celsius with enough humidity to make it difficult for humans to survive more than six hours.
“It is an upper limit to adaptability to climate change due to heat stress,” MIT researcher Elfatih Eltahir told reporters at a news conference called to discuss the findings.
Using “high resolution” climate models that assumed a “business as usual” approach to carbon emissions, the researchers predict that in cities like Doha, Qatar, Abu Dhabi, and Dubai in the United Arab Emirates, and Bandar Abbas, Iran, could exceed the 35 C. threshold several times over a 30-year period.
Extreme conditions could “characterize the usual summer day in the future,” said Eltahir.
Christoph Schaer, a professor of atmospheric and climate science at ETH Zurich who was not involved in this study, cited the dangers of heat waves from the U.S. to Russia, but said the kind of heat described in the study “concerns another category of heat waves — one that may be fatal to everybody affected, even to young and fit individuals under shaded and well-ventilated outdoor conditions.”