Steam rises from the cooling towers of the Electricite de France nuclear power station at Nogent-Sur-Seine, France, on Nov. 13. (Charles Platiau/Reuters)

THE LAST time international negotiators met to draft a major climate change agreement, they failed miserably. Expectations at the 2009 Copenhagen conference were so unrealistic they proved counterproductive.

Leaders seem to have learned a lesson. Over the next two weeks, international negotiators will try again, this time in Paris. The conclave will not solve the problem. It won’t even produce a specific plan to keep global warming below 2 degrees Celsius, the point past which scientists warn the world shouldn’t go. Given the complex and fractious nature of international negotiations, a binding treaty imposing a detailed and complete solution is not a realistic goal.

But the Paris conference may set the world on a path to significantly bend the global greenhouse emissions curve downward, build mechanisms to review countries’ progress, and establish institutions and expectations that press world governments to do more in coming years. It will be a success if it accomplishes these goals. The result should be analogous to the General Agreement on Tariffs and Trade, a post-World War II system that promoted free international exchange by regularly gathering countries in negotiating “rounds” that were expected to end in agreements to lower trade barriers. Countries will ante up in Paris and be expected to continually increase their ambition after.

More than 125 nations, including all the major emitters of gases that cause climate change, already have submitted the initial emissions-cutting commitments that will form the core of the agreement. The United States is promising to cut emissions by 26 percent to 28 percent of 2005 levels by 2025, with the Environmental Protection Agency already drawing the road map. China, whose rapid growth has translated into a huge emissions spike, is promising to peak its emissions within the next 15 years and ramp up its use of renewable energy. Chinese leaders are imposing a nationwide carbon price. Europe has had a carbon-pricing system in place for years, and it is promising to use it to cut 40 percent from 1990 levels by 2030.

A U.N. analysis found last month that, taken together, these efforts would contain the global temperature rise to about 2.7 degrees Celsius, which is significantly closer to the target than the world otherwise would have been. Other analyses make similar conclusions: IHS Energy, hardly a bastion of loopy environmentalism, released a study last week finding that countries’ emissions-cutting plans would get the world nearly half the way to the emissions reductions it needs to keep warming below 2 degrees.

IHS also warned that some countries may not keep their commitments, at least not fully. This is an inevitable risk, though smaller now that nations are more unified and determined to act. Negotiators should lower the risk further by emphasizing review and accountability mechanisms in the agreement they conclude in Paris.

For years, Republican critics have attacked the notion of doing anything serious about climate change in part because the United States acting alone can’t solve a global problem. In Paris, nations have a chance to prove this view wrong once and for all.