Written question asked by Barry Gardiner (Labour) on Monday, 7 November 2011, in the House of Commons. It was due for an answer on Wednesday, 9 November 2011. It was answered by Lord Barker of Battle (Conservative) on Thursday, 10 November 2011 on behalf of the Department of Energy and Climate Change.

Carbon

Question: To ask the Secretary of State for Energy and Climate Change what assessment he has made of the effect of black carbon on climate change; and if he will make a statement.

Answer: Research reported in the International Panel on Climate Change Fourth Assessment Report suggests a small, but significant, warming effect in the range of +0.09W/m² to +0.59W/m² since 1750 from black carbon emitted into the atmosphere by fossil fuel, biofuel and biomass burning. There is also a small warming effect due to the deposition of black carbon on surface snow and ice, which the IPCC estimated to be about +0.1 W/m². By comparison, the total warming effect from long-lived greenhouse gases is estimated by the IPCC to be +2.64W/m².Analysis by the Met Office Hadley Centre, funded by DECC, suggests black carbon aerosol emissions have potentially the second largest warming influence on climate, after greenhouse gases.

Secondary information