David Keith on Solar Geoengineering

Harvard’s Gordon McKay Professor of Applied Physics and Professor of Public Policy David Keith visited ASU to deliver a presentation on Solar Geoengineering. The presentation, sponsored by SFIS through the new Center for Energy and Society, led by SFIS Associate Director Clark Miller, focused on the risks and rewards of employing stratospheric sulfate aerosols to alter climate. In simple terms, that means infusing Earth’s atmosphere with particles that could reflect enough solar radiation to offset global warming and curb the effects of climate change.

Seeding the atmosphere with sulfates is a controversial idea. Many worry it could lead to negative changes in precipitation including acid rain, ozone depletion, or being locked into dependency on continuous distribution of the reflective particles. On the other hand, solar geoengineering has the potential to stop net carbon release and even return ozone density to pre-industrial levels some time during the next century.

Keith, himself, does not necessarily advocate stratospheric manipulation. Rather, he argues that there is a clear need for greater understanding, stressing that none of the experiments he’s designed go beyond simple science. He maintained that reflective particles could only be part of the solution to climate change along with conservation, efficiency, emissions reduction, and carbon removal. The surest way to kill the idea, he believes, would be to invest too much too soon, saying that “a Manhattan-scale project would be a terrible idea.” Conversely, Keith has previously stated that suppressing the idea without proper study could lead to quick and potentially dangerous decision-making when the crisis escalates.

Keith is a leading authority on the subject. He has been awarded Canada’s national physics prize as well as MIT’s Prize for excellence in experimental physics and was singled out as one of TIME magazine’s Heroes of the Environment in 2009. Keith has even figured in more general public media, appearing on BBC’s “Hard Talk” and Comedy Central’s “The Colbert Report.” Currently, he splits his time between Harvard and Calgary, where he is a leader of Carbon Engineering, a company working on ways to recapture carbon from ambient air.

Much of the presentation and the Q & A that followed concerned the political dimension of the question. Most support, both ideological and financial, comes from environmental donors and little or none is found in the corporate sector. Meanwhile, Keith observed that government representatives seem to agree that there should be experimentation “but no one feels like rocking the boat.” Still, Keith sensed that polarization in the scientific community may be quickly dissipating and that there would be a program in place soon “but it will be small and cautious.”

Keith’s presentation was well-timed, coming hot on the heels of the Planetary Design: Climate 3.0 event, during which experts discussed, among other relevant issues, potential solutions to climate change now that it has become too late to simply reduce carbon emissions.


View video of David Keith’s presentation.