PARIS (AFP) – Fifty-five nations including the world's top carbon polluters have registered their commitments to combat global warming, the UN climate chief said late Monday.

The pledges from both industrialised and developing countries for cutting greenhouse gases up to 2020 cover nearly 80 percent of total emissions, and provide a much-needed boost to December's Copenhagen Accord.

"This represents an important invigoration of the UN climate change talks," said Yvo de Boer, Executive Secretary of the UN Framework Convention on Climate Change (UNFCCC).

"The commitment to confront climate change at the highest level is beyond doubt," he said in a statement Monday night.

But more than a month after the nearly scuttled climate deal, rich nations have yet to say when and how they will deliver emergency funds to help poor ones begin to green their economies and cope with climate impacts.

The 30 billion dollars in so-called "fast start" financing is meant to cover the period 2010 to 2012.

Also missing for now is the list of countries that have chosen to "associate" themselves with the controversial Copenhagen Accord, which fell well short of the binding and comprehensive climate treaty once hoped for.

The UN climate forum shepherding the talks simply "took note" of its provisions after several countries refused to back it in December.

The UNFCCC's 194 member nations were later invited to endorse the deal by Sunday, January 31, and to list the actions they plan for reducing their greenhouse gas emissions.

It is still not known how many countries have opted to formally back the accord.

On the action plans, there were no surprises. The United States, the European Union, Japan and other rich nations all renewed pledges made in the run-up to the climate summit.

Rapidly developing countries led by China, India, Brazil and South Africa also reiterated voluntary national plans for curbing the carbon intensity of their economies.

But registering the commitments was widely seen as a critical step in jump-starting the troubled negotiations.

"The machine has been forcefully set in motion, it's going to put some new wind in our sails," commented French Environment Minister Jean-Louis Borloo.

The Copenhagen Accord calls for limiting warming to two degrees Celsius (3.6 degrees Fahrenheit), the threshold for dangerous impacts such as increased floods, drought and extreme weather, according to scientists.

"This is the first time that countries have ever committed to this goal. That's the good news," said Alden Meyer, a policy analyst at the Washington-based Union of Concerned Scientists.

"The bad news, of course, is that the pledges that have been put on the table to date don't put us on track to meet that goal, and would make it very difficult -- both economically and politically -- after 2020 to catch up."

The accord also commits developed countries to paying out 10 billion dollars per year to developing nations over the next three years, to be ramped up to 100 billion dollars annually by 2020.

"But it remains far from clear where the funding will come from, if it is genuinely new and additional, and how it will be allocated," said Saleemul Huq, a researcher at the International Institute for Environment and Development in London.

Many of the poor nations most vulnerable to climate change complained of being sidelined in Copenhagen, and delays in providing the financing could increase tensions as talks proceed.

Japan has taken the lead in promising some 15 billion dollars over the next three years, while the European Union has said it will stump up 10 billion.

The United States has yet to announce what share of the 30 billion it will shoulder, but analysts say it is likely to be substantially less, in the 3.5 to 4.5 billion range.

But so far none of this money has materialised.

"Looking at past experience of overseas development aid and climate funding, it may take several years to disburse even the 'fast-start' finance promised for 2010 to 2012," Huq said.

Borloo agreed that it would take some time to get the wheels turning.

"All the mechanisms have yet to be invented," he said of the 30-billion dollar fund.

"Simple bilateral aid is out of the question. We have to invent a new partnership and establish the fast-start modalities."