Climate Intervention: Reflecting Sunlight to Cool Earth, A Report from the National Research Council

The Committee on “Geoengineering Climate: Technical Evaluation and Discussion of Impacts” was charged with the task of conducting a technical evaluation of a limited number of proposed geoengineering techniques, with this talk focusing on issues related to solar radiation management (SRM) or what is also termed albedo modification.  The report comments generally on the potential impacts of deploying these technologies, including possible environmental, economic, and national security concerns. The study (1) evaluates what is currently known about the science of several selected example techniques, including potential risks and consequences (both intended and unintended), such as impacts, or lack thereof, on ocean acidification, (2) describes what is known about the viability for implementation of the proposed techniques including technological and cost considerations, (3) explains other geoengineering technologies that have been proposed (beyond the selected examples), and (4) identifies future research needed to provide a credible scientific underpinning for future discussions. The study also discusses historical examples of related technologies (e.g., cloud seeding and other weather modification) for lessons that might be learned about societal reactions, examines what international agreements exist which may be relevant to the experimental testing or deployment of geoengineering technologies, and briefly explores potential societal and ethical considerations related to geoengineering. This study is intended to provide a careful, clear scientific foundation that informs ethical, legal, and political discussions surrounding geoengineering.  This study was sponsored by the U.S. intelligence community, the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration, the Department of Energy, and the National Academies.