President Trump has decided to make good on a campaign promise to revoke the United States' commitment to the Paris climate change agreement, according to multiple reports. While Trump tweeted this morning that he would be announcing his decision "over the next few days," White House officials are leaking news of his decision to Axios, Politico, the NY Times and other outlets. From the Times:

Faced with advisers who pressed hard on both sides of the Paris question, Mr. Trump appears to have decided that a continued United States presence in the accord would harm the economy; hinder job creation in regions like Appalachia and the West, where his most ardent supporters live; and undermine his “America First” message. But advisers pressing him to remain in the accord were still pressing up to the final announcement.

The exit of the United States, the world’s largest economy and second-largest greenhouse gas polluter will not dissolve the 195-nation pact, which was legally ratified last year, but it could set off a cascade of events that would have profound effects on the planet. Other countries that reluctantly joined the agreement could now withdraw or soften their commitments to cutting planet-warming pollution.

“The actions of the United States are bound to have a ripple effect in other emerging economies that are just getting serious about climate change, such as India, the Philippines, Malaysia and Indonesia,” said Michael Oppenheimer, a professor of geosciences and international affairs at Princeton, and a member of the Intergovernmental Panel on Climate Change, a United Nations group that produces scientific reports designed to inform global policy makers.

Once the fallout settles, he added, “it is now far more likely that we will breach the danger limit of 3.6 degrees,” the average atmospheric temperature increase above which a future of extreme conditions is irrevocable.

If true, America will now join the ranks of just two other countries who have refused to commit to the Paris agreement: Syria and Nicaragua.

Trump has apparently been torn between advisers including chief strategist Steve Bannon, who advocates withdrawal on the grounds of "economic nationalism," and more moderate voices like his daughter Ivanka Trump and Secretary of State Rex Tillerson, who is scheduled to meet with Trump today. Tillerson praised the Paris deal when he was ExxonMobil’s CEO, and Politico notes that "during his confirmation hearing this year, he said the United States must keep 'its seat at the table' for international climate talks."

But last week 22 Republican Senators, including Mitch McConnell, sent a letter to Trump demanding an exit from the agreement. "Because of existing provisions within the Clean Air Act and others embedded in the Paris Agreement, remaining in it would subject the United States to significant litigation risk that could upend your Administration's ability to fulfill its goal of rescinding the Clean Power Plan," the letter reads. "Accordingly, we strongly encourage you to make a clean break from the Paris Agreement."

Republican Senator Lindsey Graham criticized his GOP colleagues following the release of the letter, warning that pulling out of the Paris accord would amount to “a statement that climate change is not a problem, is not real."

It would take years for the United States to fully withdraw from the agreement, which requires nearly every nation on earth to reduce greenhouse gas emissions and "strengthen the global response to the threat of climate change by keeping a global temperature rise this century well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius." The contribution that each individual country will make to help achieve the worldwide goal is determined by all countries individually.

The absence of the United States, the world's second-largest greenhouse gas polluter, will not prevent other Paris Agreement signatories from sticking to their commitments, but it would weaken its chances of being enforced. Without the United States, the Times reports, "there is likely to be far less pressure on major polluting countries and industries to accurately report their emissions. There have been major questions raised about the accuracy of China’s emissions reporting, in particular."