About Geoengineering

Geoengineering encompasses two different classes of approaches: carbon dioxide removal (CDR) and solar radiation management (SRM).  Potential SRM approaches that have been suggested include the deliberate introduction of sulfate aerosols into the stratosphere (e.g., by injection of sulfur dioxide), the enhancement of cloud reflectivity through increasing the number of water droplets in clouds (e.g., by using a fine seawater spray), the enhancement of surface reflectivity through whitening of roofs or planting of more reflective crops, and various space-based methods for reflecting sunlight away from Earth (e.g., reflective satellites). Potential CDR approaches that have been suggested include ocean fertilization (e.g., by the addition of iron to marine ecosystems), terrestrial biomass capture through the planting of forests or other agricultural crops, and the direct air capture of carbon dioxide with long-term geologic storage.  Geoengineering has been discussed in the scientific literature,1,2 and by various government and non-government organizations (e.g., UK Royal Society,3 Novim,4 Asilomar,5 NRC,6 GAO,7 and CRS8).

1 P.J. Crutzen, 2006. Albedo enhancement by stratospheric sulfur injections: a contribution to resolve a policy
Dilemma? Climatic Change, 77: 211–219.

2 R.J. Cicerone, 2006. Geoengineering: encouraging research and overseeing implementation, Climatic Change, 77: 221–226.

3 The Royal Society, 2009. Geoengineering the climate: Science, governance and uncertainty. The Royal Society, London, England.

4 J.J. Blackstock et al., 2009. Climate Engineering Responses To Climate Emergencies, Novim, Santa Barbara, CA.

5 Asilomar International Conference on Climate Intervention Technologies, Asilomar Conference Center in California from March 22 to 26, 2010.

6 NRC, 2010, America’s Climate Choices: Advancing the Science of Climate Change, National Academies Press, Washington, DC.

7 Government Accountability Office, 2011. Technology Assessment on Climate engineering: Technical status, future directions, and potential responses, GAO-11-71.

8 Kelsi Bracmort and R.K. Lattanzio, Congressional Research Service report on “Geoengineering: Governance and Technology Policy,” January 2, 2013; http://www.fas.org/sgp/crs/misc/R41371.pdf