LE BOURGET/UNITED NATIONS - Representatives from nearly 200 countries made common cause in the fight against climate change Saturday, adopting in Paris an agreement they hope will avert some of the worst effects of global warming and shift economies around the world to cleaner energy sources.

The agreement reached at a United Nations conference outside the French capital, the culmination of years of difficult negotiations, will mark a “historic turning point,” French Foreign Minister Laurent Fabius said when a final draft was unveiled earlier in the day.

Negotiators had been struggling to overcome deep divisions on key issues, including the pact’s long-term goals, how to address the costs of dealing with climate change , how to define the responsibilities of countries in different stages of development and how to ensure that nations fulfil their commitments.

The text adopted Saturday aims to limit the average global temperature rise since pre-industrial times to well below 2 degrees Celsius this century, while endeavoring to achieve a 1.5-degree target.

That is a more ambitious goal than organisers had set at the outset of the conference and represents a win for countries already suffering the damaging effects of global warming, including rising sea levels, prolonged droughts and extreme storms.

To achieve these objectives, however, the agreement relies on countries to set their own targets to reduce greenhouse gas emissions. The proposals currently on the table fall short of the 2-degree goal — the threshold at which scientists believe the most catastrophic effects of climate change could be avoided.

“Now comes the great task of the century: How do we meet this new goal?” Kumi Naidoo, international executive director at Greenpeace, said at a news conference. “The measures outlined in Paris simply don’t get us there.” Fabius said the deal lays out a system to review and strengthen those commitments every five years. There are also mechanisms to ensure that countries fulfil their pledges and mobilise sufficient aid to help poor countries convert their economies to cleaner energy sources and cope with global warming, he said. Reaction came swiftly once the final draft text was released, with supporters of an ambitious pact urging national leaders to adopt it but also to consider last-minute revisions. Earlier on Saturday, Foreign Minister Laurent Fabius announced to a gathering of delegates here that negotiators had reached a compromise overnight on an “ambitious and balanced” plan that would put Earth on a path toward sharply reducing emissions from fossil-fuel burning.

“Today we are close to the final outcome,” Fabius said to thunderous applause from delegates at a conference center north of Paris. He urged the delegates not to shirk from a ‘historic’ chance to stave off an environmental disaster. “The citizens of the world – our own citizens –and our children would not understand it. Nor, I believe, would they forgive us,” he said.

After a delay of several hours to allow the draft to be translated and studied, the assembly reconvened for a debate and vote that was expected late Saturday evening. At the tail end of the hottest year on record and after four years of fraught UN talks often pitting the interests of rich nations against poor, imperiled island states against rising economic powerhouses, Fabius urged delegates from nearly 200 nations to support what he hopes will be a final draft.

The accord sets a sweeping long-term goal of eliminating net man-made greenhouse gas emissions this century. It also creates a system to encourage nations to make good on voluntary domestic efforts to curb emissions and provides billions more dollars to help poor nations cope with the transition to a greener economy. Fabius said the compromise “affirms our objective … to have a temperature [increase] well below 2 degrees [Celsius],” as well as “to endeavor to limit that increase to 1.5 degrees, which should make it possible to reduce the risks and impacts linked to climate change .”

“The world is waiting with baited breath,” he said.

At a press conference, alongside French Minister Fabius, UN Secretary-General Ban Ki-moon said, “I’d like to take this moment to highlight, commend and appreciate the strong commitment and engagement of ministers, negotiators and all the staff who are engaged in this very difficult negotiation.”

“I have been attending many difficult multilateral negotiations, but by any standard, by far, this negotiation [...] is the most important for humanity,” he continued. “Very limited hours remain.”

The UN chief said there are still several outstanding issues, such as differentiation, the level of ambition and climate financing, but that thanks to many years of negotiations the parties already have “very good solutions.”

“This is not a moment of talking about national perspective. Good global solutions will help good local solutions,” he stressed, appealing to all countries to “make final decisions for humanity.” Agencies add: On the crucial financing issue, developed countries agreed to muster at least $100 billion (92 billion euros) a year from 2020 to help developing nations.

However, following US objections, it was not included in the legally binding section of the deal.

Ahead of the talks, most nations submitted voluntary plans to curb greenhouse gas emissions from 2020, a process widely hailed as an important platform for success. But scientists say that, even if the pledges were fully honoured, Earth would be on track for warming far above safe limits.

In an effort to encourage countries to improve their ambitions, the agreement will have five-yearly reviews of their pledges starting from 2023. Nations most vulnerable to climate change lobbied hard for wording in the Paris pact to limit warming to 1.5C. Big polluters, such as China, India and oil producing-giant Saudi Arabia, preferred a ceiling of 2C, which would have enabled them to burn fossil fuels for longer.

Immediately after the signing, China’s chief negotiator Xie Zhenhua told his fellow envoys the pact was not perfect.

“However, this does not prevent us from marching historical steps forward,” he said.

The United States and other rich nations countered that emerging giants must also do more, arguing developing countries now account for most of current emissions and thus will be largely responsible for future warming.

Nicholas Stern, a former chief economist for the World Bank who has become a prominent global advocate of climate action, also hailed the deal.

“This is a historic moment, not just for us and our world today, but for our children, our grandchildren and future generations,” Stern said.

“The Paris Agreement is a turning point in the world’s fight against unmanaged climate change , which threatens prosperity and well-being among both rich and poor countries.”