Reducing global warming, boosting rainfall in the Sahara now possible


A new study by the science journal indicates that deploying big wind and solar farms can help slow global warming and increase rainfall in the Sahara regions of Africa.

Researchers used computer modeling to simulate the effect of covering 20 percent of the largest desert on the planet in solar panels and installing three million wind turbines there.

The findings showed that a solar and wind farm of that size — more than 3.5 million square miles (nine million square kilometers) — would be “at a scale large enough to power the entire world.”

A combination of wind and solar farm boosted average rain across the entire Sahara from 0.24 millimeters per day to 0.59 mm per day.

The effect was not uniform across the vast desert, with the most substantial rain increase occurring in the Sahel, a semi-arid region extending from Senegal to Sudan, where residents could see 200 to 500 mm more rain per year, or about 1.12 mm per day near the wind farms.

This would be “large enough to have major ecological, environmental, and societal impacts,” said the report.

Previous studies have found that wind and solar farms can introduce significant changes in climate at the continental scale by creating rougher, darker land surfaces.

This study is the first to incorporate how vegetation would change as a result, said lead author Yan Li, a postdoctoral researcher at the University of Illinois.

“The lack of vegetation feedbacks could make the modeled climate impacts very different from their actual behavior.”

Researchers also pointed out that any hikes in temperature from solar and wind farms would be limited in geographic area and scope, unlike fossil fuel emissions which continually build in the atmosphere and raise warming over time.

“The increase in rainfall and vegetation, combined with clean electricity as a result of solar and wind energy, could help agriculture, economic development and social well-being in the Sahara, Sahel, Middle East and other nearby regions,” said co-author Safa Motesharrei, a researcher at the University of Maryland.