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.

We rated this promise Stalled in our last update based on the lack of substantive progress made at the United Nations" climate talks in Copenhagen in 2009 and in Cancun in 2010.  Those meetings produced nonbinding commitments to reduce greenhouse emissions but no follow-up to the Kyoto Protocol -- the multinational treaty, adopted in 1997, that placed binding emission reduction targets on its signatories.

The 2011 U.N. Climate Change Conference in Durban, South Africa, was seen as the last chance to renegotiate or replace the Kyoto Protocol before its expiration in 2012. The conference was also the Obama administration"s final opportunity to represent the United States in U.N. climate talks before the 2012 presidential election.

The Durban conference concluded on Dec. 11, 2011. The agreement -- known as the Durban Platform -- bore more fruit than its predecessors. The U.N. member states agreed to extend the Kyoto Protocol until 2017. The members simultaneously agreed to negotiate a new binding agreement by 2015 that would subsequently go into effect by 2020. This portion of the platform is notable because it is the first time that prominent emerging economies such as China and India have consented, at least in theory, to binding emission commitments. The fact that the Kyoto Protocol does not apply to developing nations like China was a chief reason why the United States never ratified the agreement. Finally, the platform outlined an $100 billion Green Climate Fund to assist developing countries in reducing emissions.

While these details may seem to bode well for the fight against climate change, environmental policy experts have nevertheless expressed objections about the Durban Platform. Among these objections is that the agreement delays implementation of a new treaty for almost a decade. Meanwhile, no immediate action is being taken on an international basis to limit global temperatures from rising by over 2 degree Celsius -- the point at which scientists say that the effects of  global warming will become catastrophic.    

We reached out to Steve Herz, an attorney at Sierra Club's international climate program, for his opinion on the Durban Platform. He agreed that the commitment to a new treaty and Green Climate Fund are positive developments but that there are many issues left unaddressed.

"Two big pieces of work were not done,” said Herz in an e-mail interview. "First, despite recognizing that current efforts are not sufficient to meet the 2 degree Celsius target, the Durban platform includes a very weak ‘work plan" to increase the ambition of national pledges. Second, while the Green Climate Fund was created, the parties did not agree on how the money to fill it will be raised.”

President Barack Obama"s promise was to work with the other U.N. member states on addressing climate change. Given the administration"s participation in several climate conferences, it would be inaccurate to say that it has not worked with the U.N. on this issue.

Yet clearly more work is needed to address climate change in a global, unified way. The Durban Platform, while imperfect in the eyes of many policy experts and environmentalists, may have been the best possible outcome given the past intransigence of nations like China in agreeing to binding limits on emissions. For this reason, we rate this promise as a Compromise.

When we last updated this promise in February 2009, Secretary of State Hillary Clinton had appointed a special envoy, Todd Stern, to represent the United States in climate change negotiations before the United Nations. 

So what has transpired since Todd Stern"s appointment?

The United States participated in the 2009 U.N. Climate Change Conference in Copenhagen, Denmark. The conference"s purpose was to negotiate a follow-up to the Kyoto Protocol agreement on greenhouse gas emission cuts, which is set to expire in 2012. Friction erupted between the U.S. and China, the world"s two largest greenhouse-gas emitters, over verification of emission reductions. Meanwhile, developing nations pressed industrialized countries to commit to specific emission targets. 

In the end, the United States and four other countries (China, Brazil, India, and South Africa) produced a framework entitled the Copenhagen Accord. The deal called for recognition that global temperatures should not rise more than 2 degrees Celsius and stated that developed countries would provide hundreds of billions of dollars in aid by 2020 to assist developing nations to cope with climate change. Major criticisms of the The accord was criticized because it was not legally binding and relied on countries to fairly report their own emission reduction efforts.

It was hoped that that the U.N. member states could build upon this accord with a more formal agreement during the 2010 U.N. Climate Change Conference in Cancun, Mexico. The Cancun agreement spelled out the emission-cutting commitments individual countries made in the wake of Copenhagen. Member nations also formally established a Green Fund to assist developing countries. A U.N. anti-deforestation scheme, in which developed countries would pay their developing counterparts not to cut down forests, was also agreed upon. But still no follow-up to the Kyoto Protocol was negotiated.

U.N. member states hope to expand on the Cancun agreement during the 2011 Conference on Climate Change to be held in Durban, South Africa from Nov. 28 - Dec. 9. This will be the last opportunity for President Obama"s climate negotiators to solidify an agreement before the 2012 presidential election, and the last chance U.N. member nations will have to establish a new agreement before the Kyoto Protocol expires in 2012.

It is clear that the Obama administration has worked with the U.N. on climate change. The question, however, is whether the effort has produced any substantive outcomes. Most of the pledges to come out of these talks have been nonbinding. The conflict between China and the United States have helped prevent a substantive agreement. The two countries seem to be in a holding pattern, where one will not take action unless the other does. And even if there is an agreement, it still must be ratified in the U.S. Senate. 

Experts told us they were not hopeful that any substantive agreements will come out of South Africa this year. "Although other countries may move forward with Kyoto, right now we have low hopes for climate leadership from the U.S., and therefore for an agreement that includes the U.S. We see no indication yet that the U.S. delegation's marching orders will change from trying to stall the negotiations progressing toward anything like a treaty," said Kyle Ash, Senior Legislative Representative for Greenpeace USA in an e-mail interview.

We will hold off on a definitive rating until after the conclusion of this year"s climate conference. Until then, we rate this promise as Stalled.

To help the Obama administration address global warming on an international scale, Secretary of State Hillary Clinton named Todd Stern as a special envoy for climate change on Jan. 26, 2009.

"The special envoy will serve as a principal adviser on international climate policy and strategy. He will be the administration"s chief climate negotiator," Clinton said. "He will be leading our efforts with United Nations negotiations and processes involving a smaller set of countries and bilateral sessions."

Stern coordinated initiatives on global climate change for the Clinton administration from 1997 to 1999, acting as the senior negotiator at U.N. climate talks in Kyoto and Buenos Aires.

"The time for denial, delay and dispute is over. The time for the United States to take up its rightful place at the negotiating table is here," Stern said in remarks accepting the position.

Appointing an envoy is a first step to working with the United Nations on climate change. We rate this promise In the Works.