The UK's carbon emissions were reduced by two per cent last year, which may be the result of energy firms using less coal.According to a report in the Guardian, the amount of energy supplied by coal in the UK in 2007 fell by 9.5 per cent when compared with 2006 levels. Total carbon emissions during this same time period fell from 554.5 million tonnes to 543.7 million tonnes, provisional government figures have indicated.However, some critics claim that the change has less to do with government changes to environmental policy and more to do with the cost of burning coal compared with gas."Coal became more expensive than gas so [electricity producers] switched some of their production to gas," said Robin Smale, who is an energy analyst at Vivid Economics.She added that as emissions produced by the aviation and shipping industries were not included in the government figures, they may not accurately reflect the nation's carbon footprint.Meanwhile, Environment News Service reported this week that Robin Webster of Friends of the Earth has claimed the reduction of carbon emissions between 2006 and 2007 may have been "down to good luck".