BONN, Germany (Reuters) - Countries that are signed up to the Kyoto Protocol reaffirmed plans on Friday to set new, tougher caps on greenhouse gas emissions after 2012, despite spreading skepticism about the environmental pact.
The conference of some 160 countries in Bonn set no timetable for agreeing on the goals, which would only apply to rich nations, but the talks would take at least two years.
The world's biggest polluter, the United States, was absent, having pulled out of Kyoto in 2001.
"The group has agreed an ambitious agenda to deliver new emission reductions," said Richard Kinley, acting head of the U.N. Climate Change Secretariat, wrapping up the May 15-26 talks.
It was the first meeting of a group set up by Kyoto countries last December to work out a roadmap for emissions cuts beyond 2012. Kyoto obliges 35 rich nations to cut emissions by at least 5.2 percent below 1990 levels by 2008-12.
Burning fossil fuels powers the world's energy needs but also pumps out gases such as carbon dioxide that are largely blamed for global warming of nearly 1 degree Celsius (1.8 degrees Fahrenheit) in the past century.
Scientists say catastrophic climate change could follow without emission cuts, but many countries fear the economic impacts of these, and that any burden may not be fairly shared.
Canada recently said its present targets were unachievable, while the commitment of Japan, another Kyoto ratifier, could not be taken for granted, said Michael Zammit Cutajar, head of the group driving post-2012 talks.