Sahara Desert in Libya.
With around 9 million km², it is the largest hot desert in the world. But a new study predicts a wet future for the Sahara.
The Sahara Desert, which has been around for 800,000 years, is one of the driest regions in the world, receiving only about 7.5 cm of precipitation per year — a tenth of the rain, hail and snow that falls in a rainy city like Chicago.
But, according to a study conducted by researchers at the University of Illinois (UIC), in second half of the 21st centurythe increase in global temperatures could make the Sahara much wetter.
Until then, the North African desert may experience 75% more precipitation than its historical average, say the authors of the study, presented in a recently published report on npj Climate and Atmospheric Science.
In extreme weather conditions, an increase in precipitation is also expected in the southeast and south-central Africathe researchers added.
“Changes in precipitation patterns will affect billions of people, both inside and outside Africa”, he says Thierry Ndetatsin Taguelaresearcher at the College of Liberal Arts and Sciences and lead author of the study, in a UIC statement published on .
“We have to start planning how to face these changes, from flood management to the development of drought-resistant crops”, adds the researcher
Taguela emphasizes that understanding how rising temperatures influence precipitation can help in creation of adaptation strategies.
In the study, the team used a set of 40 climate models to simulate summer precipitation in Africa in the second half of the 21st century (2050–2099), comparing it with the historical period (1965–2014), and analyzed the model results under two climate scenarios: one that simulated moderate greenhouse gas emissions and another that simulated very high emissions.
Both scenarios predict that precipitation in Africa will increasein general terms, until the end of the 21st century, with regional variations. It is noteworthy that rain in the Sahara is expected increase by 75%, followed by an increase of 25% in southeast Africa and 17% in the center-south.
In contrast, the region is predicted to southwest becomes drierwith an estimated reduction in precipitation of 5%.
“The Sahara is projected to almost double your historical precipitation levelswhich is surprising for such a dry region from a climatological point of view,” said Taguela.
“But while most models agree with the general trend toward wetter conditions, it still there is considerable uncertainty regarding the amount of rain predicted. Improving these models is essential to increase confidence in regional projections”, highlights the researcher.
Most of these projected changes are associated with the effects of climate changeas higher temperatures allow the atmosphere to retain more moisture, which in turn intensifies precipitation.
“Understanding the physical mechanisms that determine precipitation is essential to develop adaptation strategies capable of facing both wetter and drier futures”, concludes Taguela.
