Solar geoengineering could protect crops from climate change effectsSiobhan Treacy | May 26, 2021
Researchers from Harvard’s John A Paulson School of Engineering evaluated the effects of solar geoengineering on crop growth.
Solar geoengineering injects aerosols into the atmosphere to reflect sunlight and reduce global warming effects. It’s not a fix-all for climate change, but one method that could help curb the risks and physical changes. According to the team, there is little known about how solar geoengineering could affect the ecosystem and agriculture but they believe it could be key to alleviating the worst impacts of global warming on crops.
Three types of solar engineering were examined: stratospheric aerosol injection, marine sky brightening and cirrus cloud thinning. The study focused on the impact of these methods on the global yield of maize, sugarcane, wheat, rice, soy and cotton where emissions continue at the current levels.
According to the team, the most effective way to protect crops against the worst effects of global climate change is by reducing surface temperature. All three potential solar geoengineering methods have a strong cooling effect that would benefit crop yields.
In the past, studies suggested that cooling temperatures with stratospheric aerosol injection could lead to less rainfall and loss in rainfed crops. But, these studies did not consider humidity, one of the most important factors in crop transpiration and productivity. Relative humidity and vapor pressure have stronger control over plant water use and crop productivity over precipitation. The team compared agricultural productivity affected by solar geoengineering methods and emissions reduction. Emissions reductions have strong cooling and humidity benefits with a smaller benefit in crop yields than solar geoengineering. This is because the reduction of carbon dioxide fertilization also reduced productivity of most crops compared with solar geoengineering, which achieves the same temperature reduction results.
The study was published in Nature Foods.