Great and desperate measures: Geo-engineering

Abstract

Geoengineering has been defined as purposeful action intended to manipulate the environment on a very large-especially global-scale. Some researchers point out that our present manipulation of atmospheric CO2 content could be considered geoengineering, so that we are really discussing what type of geoengineering is appropriate. Geoengineering has been promoted as our fall-back option for combating global warming. However, like carbon capture and sequestration, geoengineering schemes are single-purpose technical fixes for climate change mitigation, which would leave the questions of energy availability and other global environmental problems untouched. Crucially, it does nothing to address the 'other' CO2 problem-ocean acidification. In this chapter we will restrict our discussion to large-scale schemes directed at counteracting the effects of rising GHGs by altering the Earth's albedo-the proportion of insolation that is reflected back to space. A large number of schemes have been proposed, some of which would alter the planetary albedo as a whole, while others would act on a more regional scale, with correspondingly more regional effects. Geoengineering can be implemented rapidly, and at projected costs much lower than the alternatives. Research shows, however, that it is not possible to simultaneously bring about present temperature and precipitation conditions. Because costs and benefits would be unevenly distributed across countries, it would also be very difficult, politically, to implement.