COPENHAGEN (AFP) - A landmark conference on climate change opened in Copenhagen on Monday, with grim warnings of the apocalyptic dangers for mankind if world leaders fail to agree a way to stave off global warming.

The impact on humanity of man-made drought, flood, storms and rising seas were spelt out at the start of the 12-day meeting, which will climax with more than 110 heads of state or government in attendance.

Danish Prime Minister Lars Loekke Rasmussen warned that the world was looking to Copenhagen to safeguard the generations of tomorrow.

"For the next two weeks, Copenhagen will be Hopenhagen. By the end, we must be able to deliver back to the world what was granted us here today: hope for a better future," he said.

Opening ceremonies began with a short sci-fi film featuring children of the future facing an apocalypse of tempests and desert landscapes if world leaders failed to act today.

"Please help save the world," said a terrified little girl at the end of the film.

A choir of Danish youngsters then sang a plaintive song to delegates, accompanied by a brass ensemble.

The negotiation marathon gathers members of the UN Framework Convention on Climate Change (UNFCCC), the fruit of the 1992 Rio summit.

Its rollcall of 192 nations was joined this year by Iraq and Somalia, the conference heard.

Delegates must craft a blueprint for tackling manmade "greenhouse" gases blamed for trapping solar heat and disrupting Earth's fragile climate system.

They must also put together a funding mechanism able to channel hundreds of billions of dollars to poor nations most exposed to the effects of climate change.

If all goes well, world leaders on December 18 will agree a political deal that sets down the course of action, including a roster of national pledges.