Around 12 percent of the earth will be affected by droughts in the next 86 years, a recent study shows.
Researchers at The Earth Institute Columbia University used latest climate simulation models to monitor the effects of both changing rainfall and evaporation rates in future droughts. They estimate that in 2100, around 12 percent of the land will be struck by drought due to changes in rainfall.
But the dry areas could extend to 30 percent of land if higher evaporation rates due to the added energy loss and humidity are taken into account. The researchers explain that the increase in evaporative drying indicates that areas experiencing higher rainfall that include wheat, corn and rice belts in the western US and south-eastern China, are possibly at drought risk.
So far, concern about future drought under global warming has primarily concentrated on rainfall projections. However, higher evaporation rates may also play an important role as warmer temperatures squeeze extra moisture from the soil, even in some places where rainfall is forecast to increase, the study showed.
"We know from basic physics that warmer temperatures will help to dry things out," study lead author, Benjamin Cook, a climate scientist with joint appointments at Columbia University's Lamont-Doherty Earth Observatory and the NASA Goddard Institute for Space Studies said in a press release. "Even if precipitation changes in the future are uncertain, there are good reasons to be concerned about water resources."
The latest climate report by the International Panel on Climate Change (IPCC) cautions that the soil moisture might decline globally and that already dry regions will be at greater risk of agricultural droughts.
It is also estimated that there are strong chances of soil moisture drying in the Mediterranean, southwestern United States and southern African regions, consistent with the Climate Dynamics study.
The study was published in the journal 'Climate Dynamics.'
