"We must realise that we have reached a point of no return, and have caused irreparable damage," according to the "Paris Call for Action" read out by French President Jacques Chirac after a two-day conference at his Elysee Palace. 

On Friday, the world's top climate scientists said global warming was man-made and said rising temperatures could cause more droughts, heatwaves and rising seas for more than 1,000 years even if emissions of greenhouse gases are capped.

We are coming to realise that the entire planet is at risk, that the well-being, health, safety, and very survival of humankind hangs in the balance," Chirac said after talks with politicians, scientists, business leaders and foreign leaders.

The Paris appeal seeks the creation of a new U.N. Environment Organisation (UNEO) to fight threats such as global warming, water shortages or a loss of species. And it urges "massive international action to face the environmental crisis".

The existing U.N. Environment Programme, based in Nairobi, is often faulted for having too limited powers.

The "Paris Call for Action" was backed by European Union countries and others including Algeria, Ecuador, Cambodia, Vanuatu, Seychelles, Gabon and Burundi.

But the United States, China, Russia and India -- the top four emitters of greenhouse gases -- were absent from a list handed out by Chirac's office. Carbon dioxide comes mainly from burning fossil fuels in factories, power plants and cars.

RETIREMENT

Morocco agreed to host a meeting of nations which favour the creation of a UNEO. But Chirac will retire in May after 12 years as president and it is unclear who might then champion the idea.

The proposed UNEO would be modelled on the World Health Organisation, which has more clout than UNEP, and could help coordinate government action, promote funding, research and ways to spread new technologies.

Some delegates cautioned that creating new bureaucratic institutions should not detract from action. But others said that a UNEO could, for instance, help fill gaps in science.

"We spend a great deal more on space research than trying to find out what the biosphere is all about," said Valli Moosa, head of the World Conservation Union.

He said it was unlikely that the world would achieve a goal set by governments in 2002 of slowing the rate of loss of species, ranging from exotic African frogs to rare Amazonian plants, by 2010.