Green energy combats climate change and brings life to the desert
Li, Yan, Eugenia Kalnay, Safa Motesharrei, Jorge Rivas, Fred Kucharski, Daniel Kirk-Davidoff, Eviatar Bach, and Ning Zeng. “Climate Model Shows Large-scale Wind and Solar Farms in the Sahara Increase Rain and Vegetation.” Science 361, no. 6406 (2018): 1019-022. doi: https://doi.org/10.1126/science.aar5629.
On a global scale, wind and solar powers are helping us reduce carbon emissions and combat climate change. At a regional level, the effects of installing large-scale wind and solar farms can change landscapes and harm ecosystems in ways not yet fully understood. However, recent research focusing on the impact of solar panels and wind turbines on desert landscapes highlights how renewable energy installations could bring multiple environmental benefits.
In a study published in the September 2018 edition of Science, Drs. Yan Li, Eugenia Kalnay, and Safa Motesharrei from University of Maryland analyzed the environmental impact of large-scale renewable energy farms in the Sahara Desert. The scientists simulated large wind and solar farms - large enough to generate more electricity than the whole world needs each year - in the Sahara Desert and the neighboring Sahel region. The sparsely populated Sahara Desert receives huge amounts of wind and sunlight. The Sahel is one of the poorest regions in the world, and its delicate transitional savanna-desert ecosystem is sensitive to land-use changes. The Sahara and the Sahel, with their strong exposure to wind and sun, provided researchers with ideal contexts for studying the environmental impact of massive renewable energy installations.
The researchers found that both wind and solar power farms could increase local temperature, precipitation, and vegetation, but through slightly different ways. Both solar panels and wind turbines can reduce the albedo, or the ratio of reflected sunlight to received sunlight on the land surface. A decreased albedo would change air pressure and the direction of air flow, creating extra rainfall in the region. It would also lead to a slight temperature increase. Wind turbines differ from solar panels because by changing land surface roughness, wind velocity and air pressure distribution, wind power farms can further increase the amount of rainfall in an area. The additional rain stimulated by wind and solar farms could support new plant growth. This could create a cycle of albedo reduction, rising evaporation and humidity, followed by more rainfall.
More rain and vegetation would bring life to the desert, but can increased temperature be considered a “positive effect”? The researchers argue that the slight local temperature increase from wind and solar power farms would barely influence the global mean temperature. Additionally, they mention that wind and solar power help to cool our planet and mitigate global warming in the long term by reducing carbon dioxide emissions. When taking this into account, the researchers explain that this slight regional warming would be negligible.
This research is a great news for the dry and underdeveloped Sahara and Sahel areas. On the one hand, the increased rainfall and vegetation would green the desert. On the other, investments in wind and solar energy promote economic growth in the region and provide accessible renewable energy to surrounding residential areas. Additionally, since this area is surrounded by huge existing European and Middle Eastern oil energy markets, it is the perfect place to meet existing demands with clean energy. However, the researchers do mention that results find in this study may not be applicable elsewhere, because of the specific local geography and climate of the area. What’s more, this research mainly focuses on the theoretical benefits of wind and solar installations. Practical efforts to build large-scale wind and solar power plants may have uncertain impacts on regional ecosystem and face financial and political problems.
This study shows that wind and solar power installations can do more than just reduce carbon emissions. As we strive to combat climate change, we must advance solutions that provide multiple environmental and social benefits. This research proves that installing wind and solar power plants on a large scale in the Sahara region is potentially one of these solutions.