U.N. climate negotiators will meet Monday for their last session ahead of a major conference in Paris to hammer out the details of what's envisioned to become the most ambitious agreement ever to fight global warming.
Delegates at the weeklong talks in Bonn, Germany, are expected to start line-by-line editing a 20-page draft that still contains multiple options on how to reduce the greenhouse gas emissions that scientists say are warming the planet.
Some 150 countries – including top emitters China, the United States, the European Union and India – have already made voluntary pledges to cut or curb their emissions after 2020, when the deal is supposed to take effect.
But several analyses show those pledges won't be enough to prevent levels of warming that many consider dangerous, so a key element of the Paris deal would be a mechanism to raise those commitments over time.
"We don't want to make a picture, we want to make a movie," Netherlands climate envoy Michel Rentenaar said, insisting that the Paris agreement cannot freeze the current level of ambition on climate action.
The U.N. talks have made significant strides since a 2009 climate summit in Copenhagen failed to live up to expectations.
For the first time all countries now agree they need to act against climate change, which scientists say is already transforming the planet through melting glaciers, rising sea levels, intensifying heat waves and warmer, more acidic oceans.
Though major sticking points remain, including how to spell out the different responsibilities of nations in various stages of development, rich and poor countries have moved closer in recent years.
"We have gone very far from the Copenhagen atmosphere," said Pa Ousman Jarju, Gambia's environment minister.
Risk ahead of summit
As always in the U.N. talks, which are based on consensus, there's a risk that a handful of countries block progress, he said. It would be a major setback if some countries reject the draft in Bonn, leaving negotiators with little time to come up with a new one before Paris.
Several delegates said they didn't expect that to happen, though they couldn't rule it out.
One of the most contentious issues is money. Rich countries have promised to provide $100 billion annually by 2020 to help poor countries reduce their emissions and deal with unavoidable impacts of climate change. But they are reluctant to make any commitments beyond that and say the most advanced developing nations should also chip in.
The World Resources Institute, a Washington-based environmental think tank, said negotiators must be prepared to get "their hands dirty" in Bonn and deal with the sticky issues before the Paris summit begins on Nov. 30.
"What happens in Bonn can pave the way for a universal agreement in Paris that can be the turning point on climate action that the world needs," the group said.