Nearly 200 delegates from nations around the world on Saturday approved a framework to contain carbon emissions, in a move greeted as a groundbreaking accord that requires the world's economies to take concrete steps to regulate gases linked to global warming.
After two weeks of marathon negotiations conducted in the shadow of the Paris terrorist attacks which shocked the world, national representatives put a stamp of approval on a blueprint that commits signatories to curbing climate-altering greenhouse gases.
In a statement at the White House, President Barack Obama hailed the agreement as a framework that "offers the best chance to save the one planet we have." Climate change is a signature issue frequently mentioned as being central to Obama's legacy.
"This agreement sends a powerful signal that the world is fully committed to a low-carbon future," he said. "We've shown that the world has both the will and the ability to take on this challenge."
Earlier on Saturday, French Foreign Minister Laurent Fabius called the deal an "historic" measure for transforming the world's fossil fuel-driven economy within decades, and turn the tide on global warming.
Officials appeared to have resolved the final sticking points, with key features including a more ambitious goal for limiting the rise in global temperatures to less than 2 degrees Celsius; a $100 billion a year floor for funding developing nations beyond 2020; and a five-year cycle for reviewing national pledges to take action on greenhouse gas emissions.
The accord is being interpreted as a masterstroke of international diplomacy, at a time when Western powers have encountered difficulty forging agreement on major issues facing the global economy—terrorism and the massive flow of migrants seeking asylum in the West among them. In 2009, an attempt to strike a similarly comprehensive agreement in Copenhagen ended in failure.
The Paris accord "marks a decisive turning point in our response to climate change," said Miguel Angel-Gurria, Secretary-General of the Organization for Economic Cooperation and Development, in a statement.
"I strongly applaud this historic commitment and the robustness of a deal that includes an ambitious target for limiting the global temperature rise, a five-year review cycle, clear rules on transparency, a global goal for resilience and reducing vulnerability and a framework for supporting developing countries," he added.
The American Petroleum Institute, which represents the oil and gas industry, offered a measured assessment of the deal.
The API credited the U.S. shale boom — with its massive quantities of natural gas, known for having a lower carbon profile than oil and traditional gas products—as deserving of at least some credit behind the drop in domestic carbon output in recent years.
"America's private sector has already taken the lead on reducing greenhouse gas emissions, even as we increase economic activity and domestic energy production to keep energy reliable and affordable for consumers," said Jack Gerard, API's president, in a statement.
"The United States has become the world leader in reducing carbon dioxide emissions. And EPA data show that methane emissions are also plummeting, with the largest reductions coming from hydraulically fractured natural gas wells."
Gerard added: "Our nation's 21st century energy renaissance, which has made domestically produced natural gas cheap and abundant, has helped us achieve substantial and sustained emissions reductions without command-and-control style regulatory intervention. Where other nations have pledges, we have progress and results."
At the tail end of the hottest year on record and after four years of fraught U.N. talks often pitting the interests of rich nations against poorer ones, Fabius urged officials from nearly 200 nations to support the deal.
"Our responsibility to history is immense," Fabius told thousands of officials earlier Saturday, including President Francois Hollande and U.S. Secretary of State John Kerry, in the main hall of the conference venue on the outskirts of Paris.
For the first time in over two decades, both rich and poor nations have found a common vision for curbing greenhouse gas emissions, and a roadmap for eroding two centuries of fossil fuel dominance. Still, the devil remained in the details.
The U.S. Chamber of Commerce said in a statement that the Paris conference "delivered more of the same—lots of promises and lots of issues still left unresolved."
The business organization added that the "implementation still faces the same obstacles that we've been warning about for years. None of the commitments made...are binding, and many aren't even complete. Moreover, Congress must appropriate any funds that the Obama administration has pledged."
--Reuters contributed to this article.