The UK's carbon dioxide emissions fell by 1.5 per cent in 2007, according to the Department for Energy and Climate Change.
Figures for 2007 also revealed that output of all six greenhouse gases, including methane and nitrous oxide, was down 1.7 per cent on 2006 levels.
The greatest CO2 savings were made by homes improving efficiency and business cutting energy, although certain sectors such as transport saw an increase in emissions.
The statistics put the UK well ahead of its target under the Kyoto Protocol to cut greenhouse gas emissions by 2012. Greenhouse gas emissions were down 22 per cent down on 1990 levels in 2007.
But there are more domestic stringent targets including a goal to cut carbon dioxide output, the gas which makes up the majority of the UK's emissions, by 20 per cent below 1990 levels by 2010 – which it has long been expected to be missed. Emissions of CO2 were 12.8 per cent down on 1990 levels in 2007.
The Climate Change Act has also set legally-binding targets for the UK to reduce its greenhouse gas emissions by 80 per cent by 2050 and CO2 by at least 26 per cent by 2020.
Greg Clark, Tory spokesman on climate change, said the new figures cast doubt on the targets.
"These figures show that for all Labour's posturing on climate change, emissions of carbon dioxide have fallen by just one per cent since 1997. The reason is emblematic of the failure of Labour: it signs up to targets, but has no plan to deliver them," he said.
Robin Webster, of Friends of the Earth, pointed out that the figures do not include emissions from international aviation or shipping.
"The reality is that UK carbon dioxide emissions are still higher than when Labour came to power in 1997, despite repeated promises of significant cuts," she said.
But Ed Miliband, the energy and climate change minister, said the UK would cut emissions more quickly in the next few years.
"We need to reduce emissions even more quickly and I believe the policies we are putting in place now will set us on that path to meet the challenging targets we set ourselves in the Climate Change Act," he said.