It’s called the ‘wet-bulb temperature’ – a combination of temperature and humidity which determines how climactic conditions affect the human body. Without artificial cooling, it is believed the fittest human could last for up to six hours in wet-bulb temperatures of over 35°C before survival itself becomes an issue, as the body succumbs to hyperthermia.
New research published in Nature, now suggests that the Middle East region may already be encroaching on this survival limit, and, thanks to the impact of climate change, will be well past it by the end of the century.
The Middle East is a hotspot for such extreme conditions. Low elevations, clear skies, and high water temperatures caused by the shallowness of the Persian Gulf creates high evaporation rates, and therefore high humidity. With temperatures known to hit 50°C, it’s a combination which could make the region uninhabitable for human life.
In July 2015, the wet-bulb temperature in Bandar-e Mahshahr, Iran, hit 34.6°C for around an hour. However, the study finds that the ‘business as usual’ consequences of unmitigated climate change, as set out by the IPCC, could lead to the 35°C threshold being exceeded several times over a 30-year period in major Middle Eastern cities.
This article was published in the December 2015 edition of Geographical magazine.