"This is not yet a breakthrough for a climate deal. But the EU has shown that real numbers can now be negotiated," Elise Ford, head of Oxfam's Brussels office, said.
They are entrusted with the task of simplifying a draft document full of competing proposals, disputed wording and minority-backed options.
In order to draw up a workable agreement that can be accepted by all 192 nations due to attend the December 7-18 Copenhagen conference.
But with time running out, scepticism is mounting that one of the most complex treaties in history can be reached in the Danish capital, as envisioned when the negotiations began two years ago.
Deep divisions remain among industrial countries and the developing world on commitments by the rich countries to reduce greenhouse gas emissions and on how the developing countries can lower their own emissions.
"It is realistic to say that in Copenhagen we will not be able to conclude a treaty, but it is important to lay down a political framework which will be the basis of the treaty," Angela Merkel, the German chancellor, said at the close of a European Summit in Brussels on Friday.
Even with that framework, she said, "negotiations will drag out longer until we get a treaty".
Environmental advocates caution against losing faith and momentum.
"It is crucial that we keep ambitions high," said Kim Carstensen, the global climate strategist for the World Wildlife Fund, concerned that pessimism could contribute to failure in Copenhagen.
The Kyoto Protocol required 37 countries to reduce emissions by an average 5 per cent from 1990 levels by 2012, but made no demands on emerging countries.
The US renounced it as unfair and harmful to its economy.
Over the next decade after Kyoto was signed through 2006, US emissions grew 5.5 per cent while India's grew 47 per cent and China's by 92 per cent, according to the US Energy Information Administration.
Of the 180 pages in the draft document being discussed in Barcelona, 30 pages deal with financing for poor countries to help them adjust to climate changes and to move toward a greener development path.
The European Union called on Friday for $7.5bn to $10.3bn over the next three years, scaling up gradually to €100 billion, or nearly $150bn a year, by 2020.
|Climate activists criticised the draft document discussed in Barcelona as too vague [AFP]
As much as half is expected to come from governments and public money, while the other half should derive from private investments and from the carbon market in the industrial countries.
Europe has had carbon trading since 2005, and the US Congress is considering a similar cap-and-trade scheme.
Climate activists criticised the EU paper as too vague and the funding inadequate.
The policy paper avoided saying how much Europe would contribute to the climate fund and called on all countries except the poorest to lend financial support. The EU said it would pay its "fair share" if others did too.
Oxfam International called it an "opening bid for climate justice that is nowhere near enough".