Is there a Plan B?

THE WORLD may have to fall back on little-understood and potentially dangerous "geoengineering" techniques to stem global warming if December's climate-change talks fail, says the UK's Royal Society (RS). An RS study, Geoengineering the climate: Science, governance and uncertainty, says unless future measures to cut greenhouse-gas emissions are much more successful than those taken so far, some little-tested forms of more radical intervention may be needed in the longer term. The most promising of these are Carbon Dioxide Removal (CDR) and Solar Radiation Management (SRM). CDR could take three main forms: capturing CO2 from the ambient air; enhanced weathering, which uses chemical reactions