Cheering envoys from 195 nations approved Saturday a historic accord in Paris to stop global warming, offering hope that humanity can avert catastrophic climate alter & usher in an energy revolution.
French Foreign Minister Laurent Fabius ended nearly a fortnight of gruelling UN negotiations with the bang of a gavel, marking consensus among the ministers, who stood for several minutes to clap & shout their joy, with some shedding tears of relief.
"I see the room, I see the reaction is positive, I hear no objection. The Paris climate accord is adopted," declared Fabius, the president of the talks.
Turning to a little green hammer with which he formally gave life to the arduously crafted pact, he quipped: "It may be a small gavel yet it can do huge things."
The post-2020 Paris Agreement ends decades-long rows between rich & poor nations over how to carry out what will be a multi-trillion-dollar campaign to cap global warming & cope with the impacts of a shifting climate.
With 2015 forecast to be the hottest year on record, world leaders & scientists had said the accord was vital for capping rising temperatures & averting the most calamitous impacts from climate change.
Without urgent action, they warned, mankind faced increasingly severe droughts, floods & storms, & rising seas that would engulf islands & coastal areas populated by hundreds of millions of people.
– Victory for the generations –
"It is a victory for all of the planet & for future generations," US Secretary of State John Kerry told his fellow envoys in Le Bourget on the northern outskirts of Paris.
The crux of the fight entails slashing or eliminating the use of coal, oil & gas for energy, which has largely powered prosperity since the Industrial Revolution began in the 1700s.
The burning of those fossil fuels releases invisible greenhouse gases, which cause the planet to warm & disrupt Earth's delicate climate system.
Ending the vicious circle requires a switch to cleaner sources, such as solar & wind, & improving energy efficiency. Some nations are moreover aggressively pursuing nuclear power, which does not emit greenhouse gases.
The Paris accord sets a target of limiting warming of the planet to "well below" 2.0 degrees Celsius (3.6 Fahrenheit) compared with the Industrial Revolution, while aiming for an even more ambitious goal of 1.5C.
To do so, emissions of greenhouse gases will need to peak "as shortly as possible", followed by rapid reductions, the agreement states.
The world has already warmed by almost 1C, which has caused major problems in dry developing countries, according to scientists.
Some environmentalists said the Paris agreement was a turning point, predicting the 1.5C goal would assist to doom the fossil-fuel industry.
"That single number, & the new goal of net zero emissions by the second half of this century, will cause consternation in the boardrooms of coal companies & the palaces of oil-exporting states," Greenpeace International chief Kumi Naidoo said.
– Solving money battles –
Developing nations had insisted rich countries must shoulder the lion's share of responsibility for tackling climate alter as they emitted most of the greenhouse gases since the Industrial Revolution.
The United States & other rich nations countered that emerging giants must moreover do more, arguing developing countries now account for most of current emissions & thus will be largely responsible for future warming.
On the crucial financing issue, developed countries agreed to muster at least $100 billion (92 billion euros) a year from 2020 to assist 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 billed as an significant platform for success.
But scientists say that, even if the pledges were fully honoured, Earth will still be on track for warming far above safe limits.
In an effort to obtain countries to scale up their commitments, the agreement will have five-yearly reviews of their pledges starting from 2023.
Nations most vulnerable to climate alter lobbied complex for wording to limit warming to 1.5C.
Big polluters, such as China, India & oil producing-giant Saudi Arabia, preferred a ceiling of 2C, which would have enabled them to burn fossil fuels for longer.
China's chief negotiator Xie Zhenhua said the pact was not perfect.
"However, this does not prevent us from marching historical steps forward," he said.
"This indeed is a marvellous act that belongs to our generation & all of us."
Tuvalu, a Pacific island nation of approximately 10,000 people at risk of being submerged by rising oceans, celebrated.
"We have saved Tuvalu, & in doing so we have saved the world," Tuvalu negotiator Ian Fry said.
He told AFP the 1.5C goal was legitimate for climate-vulnerable countries yet in reality, it was "a dream, & certainly too ambitious to reach."
"My disappointment is approximately action before 2020," which would assist avert future warming, Jouzel said. "There is really no ambition there at all."