Tough negotiations on the crunch issues facing the UN Climate Change Conference here got under way yesterday and were expected to continue into the night in an effort to reach agreement.
Plenary sessions were abandoned to permit a core group of countries to grapple with the task of devising rules for emissions trading, forestry, compliance and funding to assist developing countries.
The intention of the negotiators, now split up into four broadly-representative working groups, is that the outline of any deal should be conveyed to G8 leaders in Genoa, Italy, before they conclude their summit this weekend.
One of the main issues of contention remains the extent to which trees can be used as "sinks" to store carbon-dioxide and whether a liberal use of this loophole would undermine the environmental integrity of the Kyoto Protocol.
The Belgian Energy Minister, Mr Olivier Deleuze, said yesterday that proposals tabled by Canada, Japan and Australia on the "sinks" issue would open a "Pandora's box" which would result in no reduction at all in carbon-dioxide emissions.
Mr Deleuze, who currently chairs the EU Council of Ministers, said the EU's common position was that there needed to be "very tight caps" on the use of this loophole or Kyoto would be meaningless.
The EU Environment Commissioner, Ms Margot Wall strom, described the current round of talks as "a rescue operation for the Kyoto Protocol".
She said the working groups were "fully occupied" trying to hammer out a deal.
Ms Wallstrom said there was no indication that the so-called umbrella group of countries, including Canada, Japan, Australia and Russia, were not also anxious to conclude a deal in Bonn, even without US participation.
"We have to take seriously that they want to reach agreement with us on a set of rules to make the protocol ratifiable. Then it will be up to each country to decide whether it wants to ratify on that basis."
Ms Wallstrom rejected suggestions that the EU had made a mistake in rejecting the final set of terms on the table at the Hague summit last November, given that the positions of some countries appeared to have hardened since then.
The Canadian Deputy Prime Minister, Mr Herb Grey, made it clear yesterday that his government did not share the US view that Kyoto was "fatally flawed" and said Canada would ratify it if it got some concessions from the EU.
Ms Geraldine Tallon, assistant secretary at the Department of the Environment and head of the Irish delegation at the talks, said there was a "good disposition" on the part of most countries to ensure that Bonn succeeded.
Standing in for the Minister for the Environment, Mr Dempsey, who has been indisposed by a viral infection, Ms Tallon is one of the five EU negotiators in a 35-strong working group on financial aid for developing countries.
Two members of the World Wide Fund for Nature dressed as polar bears yesterday presented the first of 2,000 fans to the Japanese Environment Minister, Ms Yoriko Kawaguchi, to underline the need for "cool heads" at the summit.