United Nations General Assembly started Tuesday in New York, and with it, leaders from around the world have converged on the city to discuss humanitarian issues, global health, climate change, and more. UN Secretary-General Ban Ki-moon is using the opportunity to host a special climate event on September 21, which will collect formal ratification agreements and commitments to join “to rush the 2015 Paris climate change accord into legal force this year, hoping to bind all countries to its strictures for at least the next four years — regardless of the outcome of the presidential election in the United States,” Coral Davenport writes for The New York Times.

What’s at stake? The Secretary-General is pushing to speed the Paris Agreement’s entry into force before the next U.S. presidential inauguration, where some fear that Donald Trump, the Republican nominee who has called climate change a hoax, “could make good on his vow to withdraw the United States from the agreement — even if President Obama has signed on to it,” Davenport writes.

His push is an unusual one in the history of UN accords, Davenport notes — historically, the process of bringing international agreements into legal force has taken years, if it happens at all. As Davenport writes, “Experts in international law said they could not think of an example of a major United Nations agreement entering into legal force less than a year after it was finalized. The Paris deal was reached in December. At the time, the diplomats who forged the deal said that their goal was for it to enter into force by 2020.”

Once the agreement has met the thresholds for entry into force (joined by at least 55 countries representing at least 55% of the world’s emissions), each country will be legally bound to the deal for at least four years, even if the country’s government does not participate in the accord. “That would be enough to keep the United States legally bound to the Paris deal through the first term of a Trump presidency,” Davenport notes.