Government ministers from around the world were one step closer today to bringing a 1997 climate change treaty into force after their officials reached a key agreement.
Ministers took over the reins of the UN talks in Marrakesh, which will define the practicalities of the pact that commits industrialised nations to cut their greenhouse gas emissions by an average of five percent of 1990 levels by 2012.
Government officials, struggling for more than a week to iron out problems before the ministers' arrival, said they reached a significant breakthrough late yesterday - agreeing on a system for ensuring that countries comply with their pollution targets.
European Union Environment Commissioner Margot Wallstrom, said the progress augured well for a full agreement by Friday when the two-week conference attended by some 2,500 delegates ends.
"The atmosphere seems to be good now that we have solved some of the problems, Ms Wallstrom said.
"It seems at least the content of the compliance rules has been sorted out."
However, the head of the EU delegation, Belgian Energy Minister Mr Olivier Deleuze, sounded a note of caution.
"There might be an atmosphere of over-optimism...The work has to be done, finished in Marrakesh and it is not yet the case this Wednesday", he told a news conference.
The question of whether countries that emit more greenhouse gases than allowed under the so-called Kyoto Protocol of 1997 will face binding sanctions has proved thorny, but many delegates said it now seemed settled.