NEW YORK—Presidents and prime ministers, environmental advocates and entrepreneurs have descended on the Big Apple to help the landmark Paris climate deal take force and discuss new ways of reducing greenhouse gases.

The annual event, known as Climate Week, is in its eighth year and coincides with the opening of the U.N. General Assembly.

It is the first such gathering since nearly 200 countries agreed in the French capital in December to curb global warming through nationally determined plans to limit emissions. U.N. Secretary-General Ban Ki-moon has invited countries to deposit their instruments of ratification of Paris at a Wednesday morning ceremony at U.N. headquarters.

“I am using every opportunity to push for the early entry into force of the Paris Agreement before the end of this year,” Ban declared earlier this month.

Getting the Paris deal up and running this year has also been a priority for the United States.

“We are working together to bring that agreement into force as quickly as possible,” Secretary of State John Kerry told his international counterparts in remarks at an ocean protection summit at the State Department last week. In New York, he said, “nations will have an opportunity to do that, and in the next two months, hopefully, to bring this into force before the end of this year.”

The Paris Agreement takes effect when it is formally adopted by at least 55 countries representing at least 55 percent of global greenhouse gas emissions. The move early this month by the world’s two top emitters, China and the United States, to join the deal brought the total to 27 ratifiers covering nearly 40 percent of the world’s emissions.

Experts say about 25 countries have committed to join Wednesday morning during a one-hour General Assembly event. About five more seemed likely to firm up their plans over the weekend.

“About 30 is the number that we’re anticipating, more or less,” said U.S. Special Envoy for Climate Change Jonathan Pershing last week. “That looks like it crosses the threshold of 55 countries.”

Countries including Brazil, Mexico, Chile and Argentina will be on that list. But Wednesday’s entrants are not likely to bring enough emissions to the table to tip the deal into force. Pershing said the total emissions covered by the deal after Ban’s Wednesday event are likely to fall between 50 and 55 percent, just shy of that secondary threshold.

But the year isn’t over yet.

“A number of additional countries, at least informally, are suggesting they may be completing their work by the time of Morocco,” Pershing said, referring to the next round of U.N. climate talks, which begins in Marrakech in November.

Japan and Canada have said they plan to ratify the deal this year, and their accession would bring the deal closer to the 55 percent mark. India has not explicitly promised a 2016 ratification, but Pershing said Prime Minister Narendra Modi’s government appears to have reached the conclusion that it could ratify without parliamentary action—a position that could facilitate earlier action by the world’s fourth-largest emitter.

“I think there’s a political sense around the world of the urgency of the problem, and people believe that one of the ways that they can signal their engagement in support of the urgency is to ratify quickly,” Pershing said.

What about the European Union?

The European Union campaigned hard for a tough agreement in Paris, launching the “high-ambition coalition” with small island states and bringing one of the world’s most aggressive carbon-cutting plans to the table. But the 28-member compact warned that there would be limits to how swiftly it could join the deal because its member states’ national parliaments needed to act on Paris and on domestic energy legislation before Brussels could give the deal final approval.

Most predicted a 2017 ratification date for the compact, but that appears to be changing. French climate ambassador Laurence Tubiana told ClimateWire in Washington last week that Europe feels pressure to ratify more swiftly.

“Now in Brussels and elsewhere, they are thinking of how we can be there and not be a laggard this year. And I’m confident that we’ll find a solution,” she said. “Europe is trying to find a way to overcome the normal institutional difficulties.”

Getting the deal through national parliaments has been slow going; only France, Hungary and Austria have finished the process so far. And the pace is further impeded by the fact that so many countries are holding elections this year.

But Tubiana noted that the French presidency of the talks, the European Commission and European Parliament are all searching for alternatives, including the possibility of not waiting for national parliaments to finish their work before the European Parliament acts. There is precedent for this, but only on much more limited international agreements.

This is a good problem to have, said Tubiana, who is one of the architects of last year’s deal.

“When we decided in the last minutes of drafting the text of Paris to leave this open, we decided to do that because we hoped it would maybe be ratified before 2020, but before 2020—not the following year,” she said, calling the world’s swift action “a wonderful surprise.”

Preparing for Marrakech

Nations are expected to meet again Nov. 7 for yet another round of U.N. negotiations, this time in Marrakech, for the 22nd Conference of the Parties to the U.N. Framework Convention on Climate Change (COP 22). For Paris to be in effect on the first day of those talks, the double 55 thresholds would need to be met by Oct. 7.

But Pershing noted that there is nothing to prevent the deal from entering into force after the conference in the desert city has begun, and that would still make this year’s summit the first meeting of the parties to Paris.

That, in turn, would start the clock on negotiations for a host of decisions to guide implementation of the deal. But countries that had not yet ratified the agreement would be excluded from participating formally in those talks—an unintended consequence that the conveners are studying how to avoid.

Moroccan environment ambassador Hakima El Haite told ClimateWire last week that her country is ready if Paris takes effect during the meeting.

“We want an inclusive COP,” she said. “We don’t want to negotiate and prepare the tools to implement the Paris Agreement with 60 countries or 55 countries.”

The presidency would declare open the meeting of the parties, and those countries that had ratified the deal would be expected to agree to postpone decisionmaking until after other countries had a chance to also join the agreement, she said.

El Haite said the main priority of this year’s conference will be certainty about what countries plan to do to put themselves on a low-carbon trajectory before their commitments kick in in 2020.

Obama to attend UNGA

As a “champion” with Tubiana of the Global Climate Action Agenda, El Haite is also focused on finding ways to track commitments by subnational governments and private-sector investors and link those with the more formal, national pledges.

And this year’s negotiations must produce a road map toward the $100 billion a year by 2020 that developed countries have promised to raise to help poor nations cope with warming.

“We have pledges and announcements from countries,” she said. “We need to know if the money is already there, if we can begin to implement the project now.”

Finally, she invited heads of state to journey to Marrakech to reinforce their commitment to Paris.

“We need to maintain the trust, we need to maintain the solidarity, and we need to see the heads of state come to Marrakech and fulfill their promises,” she said. “Their presence in Marrakech will be an indicator.”

Paris drew 150 heads of state, including President Obama, but it is unclear whether many will journey to this year’s conference, which is viewed as more of an implementation conference than a messaging moment.

Obama will be in New York this week for the opening of the General Assembly, though advisers did not say whether he will participate in the Wednesday event.

Only a handful of heads of state are expected to speak Wednesday, a group that will likely include French President Francois Hollande.

Obama will convene a summit tomorrow on refugees and migration, which is expected to touch on warming as a contributor to mass displacements in the Middle East and elsewhere. And U.N. Ambassador Samantha Power told reporters Friday that he and Kerry would do “a lot of buttonholing in corridors” in New York to try to persuade countries to ratify Paris more swiftly.

Kerry, who helped to broker the Paris deal in December, will attend Ban’s ceremony Wednesday.

Reprinted from ClimateWire with permission from Environment & Energy Publishing, LLC. E&E provides daily coverage of essential energy and environmental news at Click here for theoriginal story.