Geoengineering comprises the technologies that intend to reduce global temperatures and counteract anthropogenic (human made) climate change. The technologies vary in complexity from planting trees for carbon capture to placing mirrors in space in order to reflect sunlight back into space. Geoengineering technologies are intended to remove carbon dioxide from the atmosphere and the management of solar radiation. If geoenginering technologies are implemented, they´re are expected to produce significant worldwide effects.
Geoengineering technologies attempt to mitigate global warming. These technologies are classified into two principal groups: solar radiation management (SRM) method which aims to increase the reflectivity of the Earth´s atmosphere or surface, reducing incoming solar radiation, and the carbon dioxide removal (CDR) method which intends to remove CO2 and other greenhouse gases from the atmosphere.
CDR techniques are intended to cool the planet by reducing the absorption of heat in the atmosphere. This involves the capture and storage of CO2 by chemical or biological processes. CO2 may be stored by planting trees on land which has not been covered by a forest for several years (afforestation), ocean fertilization, weathering of sedimentary rocks, among other approaches. All this is intended to reduce the warming effects of greenhouse gases by removing carbon dioxide CO2 from the atmosphere.
SMR intends to reduce or divert the amount of incoming solar radiation by enhancing the reflectivity of the earth´s surface and atmosphere. It involves the implementation of land-based technology, such as desert reflectors, and atmosphere and space technology, including cloud whitening, aerosol injection in the stratosphere and shields in space. The effectiveness of this method depends on the location, altitude and radiative properties of the atmosphere.
While CDR techniques could help reduce temperatures by decreasing CO2 levels in the atmosphere, they would require a longer time to produce considerable impact on climate change than SRM techniques. SMR methods are considered cheap and fast, and could be used in the short-term if the necessity to cool the planet arises at any given time in the future; however, further studies need to be performed in regards to the effectiveness of these technologies.
Climate change has raised international attention in the past several years. A report released by the Intergovernmental Panel on Climate Change (IPCC) in 2007 revealed evidence of global warming, and many consider that climate change may severely and catastrophically bring about serious consequences for humans and ecosystems of the world. The 2010 Convention on Biological Diversity reviews the present status and trend of biodiversity and the key factors of biodiversity loss.
Geoengineering as an emerging scientific field is at the conceptual and developmental stage, and its effectiveness at reducing global warming has not been proven yet. There are not well documented studies that can inform about the social, political and environmental consequences of these technologies. If geoengineering technologies are deployed, they´re expected to produce significant worldwide effects.