Emissions of greenhouse gases from the US fell for the first time in more than a decade between 2000 and 2003 owing largely to a shift in heavy manufacturing away from US shores to cheaper locations such as China.

James Connaughton, chairman of the White House's Council on Environmental Quality, said yesterday the decrease of 0.8 per cent in gases such as carbon dioxide, methane and nitrous oxide had been unexpected: "This was not something we would have projected."