Solar climate engineering (SCE) can be defined as a deliberate effort to cool Earth’s climate by reflecting additional solar radiation in order to compensate for global warming due to increasing greenhouse gas concentrations. Current SCE efforts are focused on one of two approaches: creating a layer of small particles in the stratosphere to mimic the effects of volcanic eruptions or adding particles to the marine boundary layer to increase the brightness (reflectivity) of marine boundary layer clouds. These efforts, both of which will be discussed, have been investigated in computer simulations but as yet have not been tested experimentally. Equally importantly, SCE presents serious issues of ethics and potential governance. Ethical issues include variants of arguments about the lesser of two evils, moral hazard, intra- and inter-generational justice, and hubris. SCE raises questions, among others, about the role of global governance and compensation for unexpected outcomes. Assessment of these issues changes as one moves from considering research to atmospheric testing and, ultimately, to deployment. The fundamental question, then, is whether there is a path forward though these intertwined issues of science, ethics and governance.

About the Speaker:

Dr. Thomas Ackerman is Professor Emeritus in the Department of Atmospheric Sciences at the University of Washington. For the past decade, he was the Director of the Joint Institute for the Study of the Atmosphere and Ocean (JISAO) at the University of Washington. From 1999 through 2006, he served as the Chief Scientist of DOE’s Atmospheric Radiation Measurement (ARM) Program and was a Battelle Fellow at Pacific Northwest National Laboratory in Richland, WA. He was Professor of Meteorology at the Pennsylvania State University from 1988 to 1999, as well as Associate Director of the Earth System Science Center. Dr. Ackerman is the recipient of the NASA Distinguished Public Service Medal and the Leo Szilard Award for Science in the Public Interest, awarded by the American Physical Society. He is a fellow of both the American Association for the Advancement of Science and the American Geophysical Union. His research interests span a wide range of climate issues from fundamental science, such as the life cycle of tropical cirrus and aerosol-cloud interactions, to applied issues, such as the impacts of nuclear war on global climate and solar climate engineering.  
                   
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