The Risks and Eﬃcacy of Solar Geoengineering
David Keith appointments are at Harvard where he serves as the Gordon McKay Professor of Applied Physics in the School of Engineering and Applied Sciences (SEAS) and Professor of Public Policy at the Harvard Kennedy School. Professor Keith has worked near the interface between climate science, energy technology and public policy for twenty years. He took first prize in Canada’s national physics prize exam, won MIT’s prize for excellence in experimental physics, and was listed as one of TIME magazine’s Heroes of the Environment 2009. David divides his time between Boston and Calgary where he serves as President of Carbon Engineering a start-up company developing industrial scale technologies for capture of CO2 from ambient air.
Solar geoengineering may enable a significant reduction in climate risks by partially offsetting climate change due to increasing greenhouse gases, however this emerging technology entails novel risks and uncertainties along with serious challenges to global governance. I will attempt a rough summary of the physics of solar geoengineering and present recent findings regarding (a) the climate’s response to radiative forcing by stratospheric aerosols, (b) methods of producing appropriate aerosol distributions, and (c) risks. In closing I will discuss the trade-off between solar geoengineering, emissions reductions and adaptation in climate policy.