Geoengineering the climate: Science, governance and uncertainty

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Description/Abstract

Geoengineering, or the deliberate large-scale manipulation
of the planetary environment to counteract anthropogenic
climate change, has been suggested as a new potential
tool for addressing climate change. Efforts to address
climate change have primarily focused on mitigation, the
reduction of greenhouse gas emissions, and more recently
on addressing the impacts of climate change—adaptation.
However, international political consensus on the need to
reduce emissions has been very slow in coming, and there
is as yet no agreement on the emissions reductions needed
beyond 2012. As a result global emissions have continued
to increase by about 3% per year (Raupach et al. 2007),
a faster rate than that projected by the Intergovernmental
Panel on Climate Change (IPCC) (IPCC 2001)7 even under
its most fossil fuel intensive scenario (A1FI8) in which an
increase in global mean temperature of about 4°C (2.4 to
6.4°C) by 2100 is projected (Rahmstorf et al. 2007).
The scientifi c community is now becoming increasingly
concerned that emissions will not be reduced at the rate
and magnitude required to keep the increase in global
average temperature below 2°C (above pre-industrial
levels) by 2100. Concerns with the lack of progress of
the political processes have led to increasing interest in
geoengineering approaches. This Royal Society report
presents an independent scientifi c review of the range
of methods proposed with the aim of providing an
objective view on whether geoengineering could, and
should, play a role in addressing climate change, and
under what conditions.