Summary They argued over apportioning carbon emissions curbs that will limit global warming.
WARSAW (AFP) - UN climate talks headed for overtime on Friday as rich and poor nations butted heads over who should be doing what to stave off dangerous planet warming.
Exhausted negotiators and ministers meeting in Warsaw geared for another late-night struggle to try to forge an ambitious climate pact, which must be signed in Paris by December 2015.
Nations remained deeply divided, delegates said. They argued over apportioning carbon emissions curbs that will limit global warming to a safer 2.0 degrees Celsius (3.6 Fahrenheit), and over funding for climate-vulnerable poor countries.
"It is indeed one sleepless night in front of us but we are still hoping to close the meeting as soon as possible," said Polish Deputy Environment Minister Beata Jaczewska, whose country has hosted the 11-day parlay.
Gathering delegates from more than 190 nations, the annual negotiations are meant to lay the groundwork for a historic deal by the end of 2015 that will brake the climate juggernaut.
With bureaucrats unlikely to reach agreement on the outstanding issues by Friday s scheduled close, "there s going to have to be a political package negotiated by ministers some time tonight or more likely tomorrow morning," said Alden Meyer of the US-based Union of Concerned Scientists.
Emmanuel Guerin with the Sustainable Development Solutions Network said a major sticking point was the demand by some developing nations for guarantees of less onerous emissions curbs compared to wealthy nations.
These nations -- which include Asian giants China and India -- are demanding a clear assurance on this point before they endorse a US-European proposal for a roadmap on how to arrive at the 2015 deal.
"They won t commit to anything without knowing what the deal will look like," Guerin told AFP.
"And they want rich nations to honour their promises," which include ramping up climate aid to $100 billion (74 billion euros) by 2020, up from $10 billion a year from 2010-12.
In hotly disputed language, the developing nations also want the deal to impose "commitments" on the West and seek only "actions" from emerging economies.
US negotiator Todd Stern has flatly said such a distinction "will not work".
As for the roadmap, Stern told journalists Friday that countries should ideally submit their initial emissions-cutting offers by about the first quarter of 2015. But a draft negotiating text made no mention of any timeframe.
