LE BOURGET, FRANCE - Ministers racing to forge a pact to save mankind from disastrous climate change were finalising a crucial blueprint on Wednesday, giving the clearest picture yet of whether a historic week in Paris will succeed.
The 195-nation UN talks have been billed as the last chance to avert the worst consequences of global warming: deadly drought, floods and storms, and rising seas that will engulf islands and densely populated coastlines.
Ministers gathered in Paris on Monday with an ambitious end-of-week deadline imposed by France to resolve complex disputes that have blocked the path to a universal climate pact for more than 20 years.
French Foreign Minister Laurent Fabius said he would deliver a streamlined draft of the hoped-for accord by 1:00 pm (1200 GMT) Wednesday, guided by the work of negotiating groups tasked with tackling the tough issues.
"It will be an important step, I hope, but not yet the final result," Fabius said on Tuesday night.
Nations remain divided over how to help developing countries cope with the costs of global warming, what limit to set for planetary overheating, how to share the burden between rich and poor nations and how to review progress in slashing greenhouse gases.
Even with a clear new draft on Wednesday, decisions on the most divisive arguments were not expected to be reached until the final moments of the negotiations.
Fabius said he wanted the new accord blueprint to remove hundreds of brackets from the old draft that denote various points of dispute, leaving the focus only on the one the key issues.
Still, there was a growing sense of optimism among negotiators that there would be no repeat of a spectacular failure six years ago in Copenhagen, the last time a global accord was attempted.
"Though we have some tough issues in the next few days to resolve I am confident that we have the ability to do it," US Secretary of State John Kerry said on the sidelines of the conference at Le Bourget on the northern outskirts of Paris.
Chinese climate negotiator Xie Zhenhua expressed similar sentiments.
"I believe we can find a comprehensive, ambitious, legally binding agreement with no person left behind. I'm fully confident," Xie said.
India's environment minister Prakash Javadekar said he was disappointed by a "low level of ambition" among rich nations, but predicted on Tuesday the world was "roughly 80 hours away" from a deal.
Taking effect in 2020, the Paris agreement would seek to limit emissions of heat-trapping greenhouse gases driven by burning coal, oil and gas - the backbone of the world's energy supply today.
The goal is to limit global warming to under two degrees Celsius (3.6 degrees Fahrenheit) over pre-Industrial Revolution levels.
One of the biggest potential deal-busters is money.
Rich countries promised in 2009 to muster $100 billion (92 billion euros) a year from 2020 to help developing nations make the costly shift to clean energy, and to cope with the impact of global warming.
But how the pledged funds will be raised remains unclear - and developing countries are pushing for a promise that the amount will be ramped in future.
Meanwhile, rich nations are insisting that developing giants work harder to tackle their greenhouse gases, noting that much of the world's emissions come from their fast-growing economies.
Singapore's Foreign Minister Vivian Balakrishnan cautioned that "faultlines remain" over how to share greenhouse gas cuts between rich and developing nations.
Small island states at risk of being swamped by higher seas are pushing for a lower warming ceiling of 1.5C.
"We are the face of vulnerability," said Philippines' climate delegate and leader of the bloc of vulnerable nations Emmanuel de Guzman.
Nevertheless, he said, countries most at risk could accept a deal with 2C as the formal goal, as long as it made a reference to the lower 1.5C threshold.
Warning of the price of inaction, Kerry said the United States spent $126 billion last year undoing the damage of eight huge storms.
The top US diplomat also described the splintered wood he had seen strewn across the mountains of the Philippines in the path of Super Typhoon Haiyan that struck in 2013, leaving more than 7,350 people dead or missing.
"That's the future,folks, unless we tame this monster that we have unleashed," he said.