Professors Develop Climate Model

In an attempt to explore ways to stabilize rising global temperatures, a team of researchers including Applied Physics Professor David Keith has developed a plan to quantify and model the effects of solar radiation management (SRM)—techniques to reflect sunlight back into space.

Dubbed the “planet hacking” project, SRM aims to combat rising global temperatures by mitigating the “greenhouse effect,” which traps solar radiation near the Earth’s surface. For example, SRM techniques may add aerosols to the upper atmosphere, thereby scattering light and limiting the greenhouse effect.

Keith and his colleagues provide a framework for analyzing the potential benefits of exploring SRM techniques more deeply, concluding that further testing of SRM would be beneficial.

“Our goal was to examine the all-or-nothing assumption common in studies of SRM, by using climate models to find out if a limited test of SRM could be detected in the face of natural climate variability,” Keith said in a SEAS press release.

“Our results suggest that it should be possible to turn SRM on slowly—looking carefully for unexpected side-effects—before committing to full-scale use.”


Though SRM may help combat rising global temperatures, environmentalists worry that such protocols would deter nations from enacting stricter emissions policies.

“There is a taboo when it comes to talking about this because there is an underlying feeling that even talking about technical fixes like this will encourage people not to cut emissions,” Keith said.

Nonetheless, Keith said inaction is more harmful to the environment than the effects of solar radiation management.

According to an opinion article Keith published in the January 2010 issue of Nature, solar radiation management could offset rising temperatures 100 times more cheaply than emission cuts.

Though the project is very economical, Keith said that it may still be a risky proposition.

“This is not a cost-benefit trade-off,” Keith said. “It’s a risk-risk trade-off, so doing this stuff has some risks, including some very serious global risks, but it has some potential large benefits.”