The Azimuth Project
Geoengineering (Rev #4)



Geoengineering is a name for various proposals to deliberately manipulate the Earth’s climate to counteract the effects of global warming. The National Academy of Sciences has defined geoengineering as “options that would involve large-scale engineering of our environment in order to combat or counteract the effects of changes in atmospheric chemistry”:

  • Committee on Science, Engineering, and Public Policy (COSEPUP), National Academy of Sciences, Policy Implications of Greenhouse Warming: Mitigation, Adaptation, and the Science Base, Section 28: Geoengineering, 1992.

The 2007 IPCC report concluded that geoengineering options, such as ocean fertilization to remove CO2 from the atmosphere, remained largely unproven. It was judged that reliable cost estimates for geoengineering had not yet been published:

However, there is still considerable interest in geoengineering, because many people deem it difficult to reduce carbon emissions in time to prevent dangerous global warming.

Example proposals

There is an analysis by Tim Lenton of the University of East Anglia which concludes that only geoengineering that reflects sunlight are able to have a large enough effect over a sufficiently short time interval. (He also projects that most of these are mechanisms that need continually replenishing, and in the event of discontinuing an even more dramatic rise in temperatures could occur.)


category: climate