MADRID - A UN climate summit in Madrid was facing failure Saturday after all-night negotiations between countries left them more divided than ever over how to fight global warming and pay for its ravages.

Delegates from rich nations, emerging giants and the world's poorest countries all objected to a draft final text unveiled by host Chile in a botched attempt to find common ground.

Following a year of climate-related catastrophes including deadly storms, flooding and wildfires, as well as weekly strikes by millions of young people, negotiations in Madrid were meant to send out a clear signal of governments' willingness to tackle the crisis.

The COP 25 summit also aimed to finalize the rulebook of the landmark 2015 Paris accord, which goes into effect next year.

Instead, delegates on Saturday were exasperated at what they called backwards steps on the key political issue -- how far each nation is willing to go to help stave off climate catastrophe.

"All the references to science have gotten weaker, all references to enhancing the (ambition) have gone, it seems we prefer to look backward rather than looking forward," Carlos Fuller, head of the Association of Small Island States negotiating bloc, said in plenary of the draft COP 25 final text.

Even after marathon talks between ministers, observers and delegates told AFP there were still significant splits on a number of issues.

Old divisions between rich polluters and developing nations re-emerged in Madrid over who should slash greenhouse gas emissions by how much, and how to pay the trillions needed for humanity to adapt to a climate-addled world.

Newer fissures, meanwhile, between poor, climate-vulnerable nations and emerging giants such as China and India -- the world's No.1 and No.4 emitters -- also blocked progress.

In Saturday morning's public discussions, additional discord surfaced on how nations should refer to a string of scientific assessments of the state of the planet.

But the bottom-line ask for climate-vulnerable nations remains some signal that all countries are willing to improve on emissions reduction commitments that would see the world careen toward runaway global warming. -AFP