Tuesday, February 12, 2013 – 5:00pm
Haller Hall, Geo Museum 102, 24 Oxford Street, Cambridge
“Smoke and Mirrors: Is Geoengineering a Solution to Global Warming?” with Alan Robock, Department of Environmental Sciences, Rutgers University
ABSTRACT: In response to the global warming problem, there has been a recent renewed interest in geoengineering “solutions” involving “solar radiation management” by injecting particles into the stratosphere, brightening clouds, or blocking sunlight with satellites between the Sun and Earth. While volcanic eruptions have been suggested as innocuous examples of stratospheric aerosols cooling the planet, the volcano analog actually argues against geoengineering because of ozone depletion and regional hydrologic responses. In this talk, I describe different proposed geoengineering designs, and then show climate model calculations that evaluate both their efficacy and their possible adverse consequences. No such systems to conduct geoengineering now exist, but a comparison of different proposed stratospheric injection schemes, using airplanes, balloons, and artillery, shows that using airplanes to put sulfur gases into the stratosphere would not be expensive. Nevertheless, it would be very difficult to create stratospheric sulfate particles with a desirable size distribution. Our GeoMIP project, conducting climate model experiments with standard stratospheric aerosol injection scenarios, is ongoing, but has already shown that temperature and precipitation responses would be uneven globally.