Imagine a world where even the most basic outdoor activities can put your health or even your life at risk. No, that’s not a cheesy trailer for a Hollywood sci-fi flick about life on a remote desert planet. It’s a real-life scenario about life in the Persian Gulf region right here on Earth at the end of this century, laid out in a startling new study in the current issue of the journal Nature Climate Change.
The study, by researchers at Loyola Marymount University and MIT, projected temperature and humidity increases in far southwestern Asia between 2071 and 2100 based on current greenhouse gas emissions trends. It found that a key threshold of human habitability — essentially heat plus humidity — is expected to “exceed (the) threshold of human adaptability” several times across the region over those 30 years.
It also found that temperatures reached on the hottest five percent of summer days in the region now will become more or less the norm for summers in that future.
“We are looking at heat waves, severe heat waves in that region,” says Elfatih Eltahir, a civil and environmental engineer at MIT and a co-author of the study, in which a combined calculation of temperature and humidity — commonly referred to as mugginess but which the scientists refer to as “wet-bulb” temperature — exceed 35 degrees Celsius, a level equivalent to the National Weather Service’s National Weather Service’s heat index of 165 degrees Fahrenheit.
Above that level, Eltahir says, “the ability of the human body to adapt to the warm conditions becomes very limited.”
This threshold, Eltahir and his co-author Jeremy Pal write, “defines a limit of survivability for a fit human under well-ventilated outdoor conditions and is lower for most people.
“We project ... that extremes of wet-bulb temperature in the region around the Arabian Gulf are likely to approach and exceed this critical threshold under the business-as-usual scenario of future greenhouse gas concentrations.”
The “business-as-usual scenario” means a future in which no dramatic steps are taken to reduce the emission of greenhouse gas pollution that are helping trap more heat in the Earth’s atmosphere.
The researchers emphasize that this danger level won’t be the norm everywhere, all year round in the region, so much as an increasingly common summertime event
Depending on the location, Eltahir and Pal say they expect such conditions “in some places, once every decade. In others, several times a decade. So it’s not like this will be the normal heat level all the time, but there will be severe heat waves experienced in that part of the world.”
At such times, Eltahir says, people in wealthier regions will be able to adapt through increased air conditioning and other means. But even in these places, he and Pal write, “even the most basic outdoor activities are likely to be severely impacted.”
In less wealthy parts of the region, for example in Yemen along the Red Sea, where homes and other buildings are largely without air conditioning, people “will probably suffer both indoors and outdoors. ... Under such conditions, climate change would possibly lead to premature death of the weakest — namely children and the elderly.”
It’s uncertain how the report will be received in the region, where economies tend to be heavily reliant on the very stuff that’s helping cause the climate crisis — petroleum — but where oil money has largely buffered residents from the impacts of environmental change.
But journalist Razan Alzayani, who grew up in the United Arab Emirates and now lives in Dubai, says she hopes it will be a “wake-up call” for the region.
“It’s the shock that people need to realize that this is a tangible thing,” Alzayani says. “The timeline they’re talking about is the end of the century and we’re talking about our grandchildren. And the fact that this world that we’re creating is so uninhabitable for them… made me kind of sad,” says Alzayani.
Alzayani says she already senses a change in the region. Summers have been feeling longer and winters aren’t as cold as when she was young.
“It’s the end of October and it feels like the summer is extending much longer than it should this year,” she says.
One place where the reality of dangerous warming could hit a raw nerve is the Muslim holy city of Mecca, in Saudi Arabia, the birthplace of the Prophet Muhammad. All Muslims are supposed to visit Mecca at least once in their lives, in the annual pilgrimage called the Hajj. But the rite, which often falls during the summer, has become increasingly crowded and sometimes deadly in recent years, and the prospect of adding super-charged heat to the mix is worrying.
"You can only wonder how [the Hajj] will look in a few years’ time if the temperatures are to rise even further," says Nicholas Niksadat of the BBC Persian service.
It’s a concern shared by the report’s authors.
“These extreme conditions are of sever consequence to the Muslim rituals of the Hajj,” Eltahir and Pal write. “This necessary outdoor Muslim ritual is likely to become hazardous to human health, especially for the many elderly pilgrims, when the Hajj occurs during the ... summer.”
The one saving grace in their study, Eltahir says, is that this future may be avoidable if countries of the world act together to significantly reduce, or mitigate, greenhouse gas pollution at the upcoming global climate summit in Paris.
“Serious global mitigation efforts are no longer optional,” says Eltahir. "I think of them as a necessary step that has to be taken, in order to avoid consequences like this.”