Developed countries, taken as a group, have achieved sizable reductions of greenhouse gas (GHG) emissions, but further efforts are needed to sustain these reductions in gases blamed for global warming and cut them further, a United Nations climate body warned today.

The acting head of the secretariat of the UN Framework Convention on Climate Change, Richard Kinley, emphasized that a large part of the reductions was achieved in the early 1990s in countries of Eastern and Central Europe undergoing transition to a market economy.

"National efforts to implement the Climate Change Convention and to prepare for the implementation of the Kyoto Protocol have already resulted in emission reductions," he said of the pact that requires 35 industrialized nations to reduce greenhouse gas emissions by 5 per cent by the year 2012. Compared to 1990 levels, their GHG emissions were down 5.9 per cent in 2003.

But, Mr. Kinley warned, "What we see is that the emissions from developed countries as a group have been stable in recent years and not decreased as they did in the early 1990s. "Moreover, GHG projections indicate the possibility of emission growth by 2010. It means that ensuring sustained and deeper emission reductions remains a challenge for developed countries," he said. The findings are supported by a new UNFCCC publication, ( Key GHG Data, the first publication covering all GHG data officially submitted by developed and developing countries under the Climate Change Convention.

The study includes data on greenhouse gas emissions from 40 developed and 121 developing countries, presented in a reader-friendly form. The UNFCCC secretariat is confident that "Key GHG data" will become a recognized source of authoritative, transparent and easy-to-read information on greenhouse gas emissions.

The Kyoto treaty came into force in February after Russia ratified it. After President George W. Bush withdrew United States support in 2001, Russian ratification became vital since 55 Parties to the UNFCCC had to ratify the Protocol, including the developed countries whose combined 1990 emissions of carbon dioxide exceed 55 per cent of that group's total. Russia, with 17 per cent, pushed the amount over the threshold. The US accounts for about 24 per cent of global fossil fuel-related carbon dioxide emissions.