Or at least make it significantly greener than it is now.
"Our model results show that large-scale solar and wind farms in the Sahara would more than double the precipitation, especially in the Sahel, where the magnitude of rainfall increase is between 20mm and 500mm per year," said Dr Yan Li, the lead author of the paper from the University of Illinois, US. "As a result, vegetation cover fraction increases by about 20%." In the Sahel, the semi-arid region that lies to the south of the Sahara, average rainfall increased 1.12mm per day where wind farms were present, according to the study.
With wind turbines, it's all about the mixing of air caused by the rotation of the blades. Wind farms mix warmer air from above, which creates a feedback loop whereby more evaporation, precipitation and plant growth occurs.
Solar panels actually reduce the reflection of sunlight from the surface known as the albedo effect. This triggers a positive albedo-precipitation-vegetation feedback that leads to precipitation increases of about 50%, the authors report.
"Precipitation increases predicted by our model would lead to substantial improvements of rain-fed agriculture in the region, and vegetation increases would lead to the growth in production of livestock," said Dr Safa Motesharrei, from the University of Maryland, another author of the paper.
Of course what he should have said was, "We will change the face of Arrakis !"
https://www.bbc.com/news/science-environment-45435593
I am generally very worried when climate engineering rears its ugly, unforeseen-consequences-filled head, but this one looks interesting.
ReplyDeleteThough, this 20% increase in vegetation fraction, it is about total surface, right? Not existing fraction?
From the context of discussing the relative increase in rainfall, I'd assume the 20% increase is also relative to the existing fraction, not total area.
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