Climate change is one of the greatest challenges facing the global community.  However, global consensus on an international framework to reduce or stabilise emissions is proving impossible to reach, while concentrations of greenhouse gases in the atmosphere are rising apparently inexorably.  "Geoengineering", the intentional modification of our climate to counteract global warming, is a possible solution, or at least part-solution, to this critical issue.

Many possible geoengineering strategies have been proposed, including placing mirrors in orbit around the Earth or injecting aerosols into the upper atmosphere in order to reflect a fraction of incoming sunlight, growing highly reflective crops, or fertilising the oceans with iron in order to draw more CO2 out of the atmosphere and into the oceans.

More work is urgently needed before an informed decision can be made as whether such schemes are viable, or, more importantly, potentially dangerous.  Critical questions that remain include:

• What are the climatic impacts of various geoengineering schemes - which are most effective in reverting to a 'pre-industrialised' climate?  Can these be predicted with a sufficient accuracy to warrant implementation?
• What are the regional impacts of such schemes - will there be 'winners' and 'losers' in different countries?  How can any such inequality be managed?
• Can we build a global framework for deciding the optimum combination of reducing emissions/geoengineering/energy efficiency, given the environmental, economic, social, and political pressures that are brought to bear?

Malcolm Fairbrother is currently working on the area of climate, economic growth and national preferences for geoengineering.

View his research presentation.