UN negotiators opened a final round of talks in Bonn on Monday to thrash out the wording of a universal climate rescue pact to be inked in Paris in December.
Developing nations have objected to the latest, shortened blueprint for the agreement, saying some of their key demands have been dropped.
The five-day session is the last official meeting of rank-and-file negotiators to lay the groundwork for heads of states and ministers to seal a deal meant to curb global warming.
The pact, to take effect in 2020, will be the first agreement to include all 195 of the UN climate forum's member nations.
The joint (NasdaqCM: JYNT - news) chairmen of the talks have whittled the draft down from 80 pages to 20 since the last round of negotiations in September, to serve as the basis for this week's talks.
But initial reactions have been sceptical, especially from developing nations which insist that deleted passages be restored before the job of line-by-line text bartering can begin.
"We demand that the text be balanced for negotiations to commence," said Gurdial Singh Nijar, a spokesman for the Like-Minded Developing Countries (LMDC) group which includes major emitters China and India as well as many African, Asian and Latin American nations.
A key concern was wording on $100 billion (88 billion euros) in finance that the developed world had promised to mobilise by 2020 to help poorer nations make the shift to less-polluting energy and adapt to the unavoidable effects of global warming such as sea-level rise.
The new draft "completely ignored the submissions of G77 on finance," Nijar told AFP. The G77+China is a more than 100-strong grouping that includes the LMDCs, African nations and the Alliance of Small Island States (AOSIS) -- all of which object to the current wording.
"The current text neither satisfies the concerns of all parties, nor would it lead to the actions required to avert a global calamity," said AOSIS chairman Thoriq Ibrahim of the Maldives.
Peru's environment minister Manuel Pulgar Vidal, who is presiding over the talks, recognised the disappointment of some parties.
But he told delegates that throwing out the new draft was not an option.
Instead, he urged them to "work constructively in trying to find a fair, ambitious and pragmatic outcome."
He added: "The whole world is looking at us. The (Paris) agreement must launch the transformation of our economies toward a low carbon and resilient... society."
Climate envoy Laurence Tubiana of conference host France said the current blueprint "lacks ambition on all the elements," adding: "We are here today and for the rest of the week to correct these weaknesses."
Nations have agreed to finalise a deal at a November 30-December 11 UN conference in the French capital.
The overarching goal is to limit average global warming to two degrees Celsius (3.6 degrees Fahrenheit) over pre-Industrial Revolution levels -- beyond which scientists say the impacts will be disastrous (Other OTC: UBGXF - news) .