Scorching temperatures are already standard for people living in the Gulf states, but by the end of the century, parts of the region could become so hot that it will be impossible for humans to spend time outside, a new study has warned.

The authors of the paper, published in the journal Nature Climate Change, said that major cities in the region, including Abu Dhabi, Dubai, and Doha, "are likely to experience temperature levels that are intolerable to humans" if climate change persists.

Using a measurement method called 'wet-bulb' temperature - described as "a combined measure of temperature and humidity" - the authors put the threshold for human survival at 35 degrees Celsius.

Being exposed to such conditions for more than six hours "would probably be intolerable even for the fittest of humans", the report said.

In order to forecast how future climate change would affect wet-bulb temperatures in the Gulf, the researchers ran a regional climate model following two different trajectories.

"[The scenarios are] 'business-as-usual' with severe climate and intolerable heat waves for the region of Southwest Asia, or a scenario with significant mitigation at the global scale that would avoid the serious impacts on the region," Elfatih Eltahir, the co-author of the report and a professor of civil and environmental engineering at MIT, told Al Jazeera.

In the business-as-usual scenario, where the current pace of greenhouse gas emissions is maintained, the researchers found that wet-bulb temperature would exceed the 35C threshold several times over a 30-year-period by the end of the century in cities like Abu Dhabi, Dubai, Doha, Dhahran and Bandar Abbas, Iran.

"These are important future projections with serious implications," Eltahir said.

"The time is now for action to be taken at a global scale," he added, noting that if climate change continues at the same pace the severe conditions that now happen roughly once every 20 summer days will become a normal occurrence.

In such extreme conditions, researchers warned that "even the most basic outdoor activities are likely to be severely impacted".

In particular, they cited the potential danger for the millions of Muslims attending the annual pilgrimage of Hajj.

"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 boreal summer," the authors said.

Commenting on the findings of the report, Al Jazeera's senior weather presenter Robert McElwee said: "Without any sort of mitigation, Gulf countries all exceed the deadly 35C wet-bulb temperature - a figure directly related to humidity - as a daily average.

"Anyone who has experienced the high humidity of a Gulf summer can relate to the debilitating nature of high humidity at high temperature.

"With mitigation adopted globally, the contrast is stark - no Gulf nation would reach the deadly conditions regularly, just more often than now."

Source: Al Jazeera