Prompted by the slow progress of global GHG reductions, the uncertainties of climate sensitivity, the potential existence of climate thresholds, and the political, social and economic impact of pursuing aggressive mitigation strategies, some in the international community have begun considering alternatives to address potentially catastrophic climate change. One such alternative is the use of geoengineering technologies. Geogineering technologies aim to intervene in the climate system through large-scale and deliberate modifications of the Earth's energy balance in order to reduce temperatures and counteract anthropogenic climate change. This book explores the diverse methods, technological characteristics and possible consequences of geoengineering.