France and others argue no existing body is really equipped to tackle the crisis and a new one should be created.

"We have no problem with a new agency that can speak at cabinet level and has the power to knock a few heads together," said Gordon Shepherd, policy head at WWF International. "But it must not be used as an excuse for governments to do nothing in the meantime."

The French proposal for a United Nations Environment Organisation, originally floated at the Johannesburg Earth Summit in 2002 and revived three years later, has some 40 backers -- mainly from francophone nations.

Ranged against the proposal, for a variety of reasons, are the United States, Brazil and China. The Organisation for Economic Cooperation and Development has offered its own services.

Environmentalists note at least 20 UN bodies from its environment programme (UNEP) to its refugee agency (UNHCR), health organisation (WHO) and food body (FAO) cover the effects of climate change to some degree.

"There is an existing vehicle," said Shepherd. "It doesn't work very well but it can be helped in the interim while the new agency is set up."

Some diplomats argue the French idea would be a mistake given the need for immediate global action.

Scientists say that burning fossil fuels for power and transport will raise global average temperatures by between 1.8 and 4.0 degrees Celsius this century, leading to worse floods, famines and epidemics and forced migration for millions.

Illustrating the scale of the climate crisis, scientists in the United States have discovered that Arctic ice is retreating three times faster than previously predicted.

"What we have is far from perfect, but it does function to an extent. Starting from scratch now would be like rearranging the deckchairs on the Titanic after it hit the iceberg," said a British climate diplomat, on condition of anonymity.

The Kyoto Protocol is the only broad agreement to reduce emissions of greenhouse gases, but the United States rejected it in 2001 on the grounds that its economy would be damaged and that it was not binding on booming emitters China and India.

Kyoto's first phase runs out in 2012 and so far there is no agreement on how to extend and expand it.