Obama's promise to work out a climate change agreement with the United Nations came to fruition at the December 2015 climate change talks in Paris.
The deal, negotiated by nearly 200 nations, aims to keep global temperatures from rising below 2 degrees Celsius (with an aspirational target of 1.5 degrees) from pre-industrial levels by 2100 and to reach net zero emissions by the second half of the century.
To meet these goals, countries are required to submit plans detailing how they will reduce greenhouse emissions and to report their progress every five years beginning in 2023, which will be monitored and verified. Developing countries also pledged $100 billion in annual funding to developing countries.
The Paris agreement, which takes effect in 2020, entered into force Nov. 4, 2016, after it met the ratification threshold of 55 countries, including the United States, accounting for 55 percent of global emissions. (As of Dec. 1, 2016, 115 countries have ratified the Paris agreement.)
Green groups and experts praised its symbolic heft as the first global agreement on climate change in history. They applauded President Barack Obama for gathering support among world leaders, particularly in bringing China and India to the table.
"It goes without saying that we would have not had the global community come together were it not for U.S. leadership and our skilled diplomacy abroad," said Sara Chieffo, the vice president of government affairs at the League of Conservation Voters. "He cultivated some extremely important breakthrough moments with China ahead of the negotiations."
China and the United States are the world's two largest polluters and account for just under 40 percent of global emissions. Together, they formally joined the Paris agreement in September 2016, with the United States pledging to cut emissions between 26 and 28 percent from 2005 levels by 2025.
Because the Paris agreement was not an official treaty, Obama was able to sidestep the Senate and used executive authority to ratify it — a "really smart policy move since you know Congress was never going to approve any top-down treaty," said Josh Howe of Reed College, who wrote the book Behind the Curve: Science and the Politics of Global Warming.
Yet the deal is not without critics. Leading climate change activist Bill McKibben called it "mediocre, but real" in an interview with PolitiFact. James Hansen, a prominent former NASA scientist who warned Congress about climate change in 1988, blasted the Paris deal as "a fraud." (Hansen could not comment given his ongoing climate change lawsuit against the U.S. government.)
And the legacy of the deal could be short lived. Obama's successor, President-elect Donald Trump, said he will pull out of the Paris agreement in May 2016 (though he has softened his position since winning the election) — a promise that experts say will hurt his negotiating leverage in other areas like trade and also damage U.S. credibility abroad.
Multiple Paris signatories like China, Brazil, India and the European Union pledged their commitment to the agreement, despite Trump's intentions, at the 2016 U.N. climate change talks in Marrakech, Morocco.
Regardless of what happens under a Trump administration, Obama played a key role in working with the U.N. to hash out the Paris agreement. We rate this as a Promise Kept.