Pumping reflective particles into the atmosphere might cool down the planet, but what other consequences could it have? In A Case for Climate Engineering, physicist David Keith argued for a concerted research program into the effects of such a geoengineering plan, known as solar radiation management. Dave Levitan reviewed the book in Conservation’s previous issue (“We Are as Gods”).
Some results on the consequences of geoengineering are starting to come in. Researchers at the University of Reading in the U.K. modeled what would happen if a huge amount of sulfur dioxide aerosols—enough to counteract the warming caused by quadrupling atmospheric CO2 concentrations—were injected into the stratosphere. They found that the tropics could see a nearly 30 percent reduction in rainfall. The particles effectively blocked incoming heat from the sun, but they also absorbed heat reflected off the earth’s surface. This decreased the air temperature difference between surface and stratosphere, thereby dampening the convective upwelling that produces precipitation. Next, the researchers plan to identify which regions would be most affected by solar radiation management and to calculate economic risks.
1. Ferraro, A.J., E.J. Highwood and A.J. Charlton-Perez. 2014. Environmental Research Letters doi:10.1088/1748-9326/9/1/014001.