The world is bracing for President-elect Donald Trump to withdraw the U.S. from the Paris climate agreement for the second time — only this time, he could move faster and with less restraint.

Trump’s vow to pull out would once again leave the United States as one of the only countries not to be a party to the 2015 pact, in which nearly 200 governments have made non-binding pledges to reduce their planet-warming pollution. His victory in last week’s election threatens to overshadow the COP29 climate summit that begins on Monday in Azerbaijan, where the U.S. and other countries will hash out details related to phasing down fossil fuels and providing climate aid to poorer nations.

The United States’ absence from the deal would put other countries on the hook to make bigger reductions to their climate pollution. But it would also raise inevitable questions from some countries about how much more effort they should put in when the world’s second-largest greenhouse gas polluter is walking away.

“Countries are very committed to Paris, I don’t think there’s any question about that,” said David Waskow, head of the World Resources Institute’s international climate initiative. “What I do think is at risk is whether the world is able to follow through on what it committed to in Paris.”

The Trump campaign told POLITICO in June that the former president would quit the global pact, as he did in 2017 during his first stint in the office. A campaign spokesperson did not respond to a request for comment for this story.

Trump said as recently as last weekend that climate change is “all a big hoax.”

“We don’t have a global warming problem,” he said at a campaign appearance, in spite of a mountain of data that says otherwise — and projections that 2024 is set to be the warmest year on record, surpassing a milestone set last year.

Once Trump takes office in January, he could file a request to the U.N. to withdraw from the agreement again. It would take a year for that move to take effect under the terms of the pact, not the three years it did previously.

Over that time, the Trump administration could ignore past U.S. climate commitments established by President Joe Biden and refuse to submit any new plans for reducing greater amounts of carbon pollution, according to analysts.

As POLITICO reported in June, some conservatives have also laid the groundwork for Trump to go even further if he chose to. One option would remove the United States from the 1992 U.N. treaty underpinning the entire framework for the annual global climate negotiations, a much more definitive step that could do lasting damage to the effort to limit the Earth’s warming.

Either way, a U.S. withdrawal could leave the country sidelined from international discussions about the expansion of clean energy, allowing China to continue out-competing America on solar panels, electric vehicles and other green technologies, said Jonathan Pershing, a special envoy for climate change during the Obama administration.

“China is the world’s largest trading partner for virtually every country in the world, so their ability to influence is not diminished,” he told reporters Thursday. “If anything, it is increased with U.S. withdrawal.”

He added: “I think we lose when the U.S. is out, and with the U.S. out, China will step up, but in a very different way.”

The U.S. was an architect of the 2015 Paris Agreement, which requires the 195 countries that signed it to submit national plans for cutting greenhouse gas emissions and provide updates about their progress toward hitting those marks. It also calls on wealthier nations to pay for climate projects, but there are no penalties for not adhering to the agreement.

In the nine years since it was established, climate pollution has continued to rise globally — though arguably at a slower rate than without it. Disasters have hit harder from Nepal to North Carolina, inflating the need for climate finance into the trillions of dollars each year.

A second exit

The Paris Agreement was about a year old when Trump announced that he served the people “of Pittsburgh, not Paris” and was withdrawing. The move stirred international shock — and fears that other countries might follow the U.S. out the door.

Now the agreement “is in a different stage in its existence,” said Todd Stern, who helped finalize the Paris deal as the U.S. climate envoy. “I would be very surprised to see countries actually pull out.”

Biden reentered the agreement in 2021 and then announced that the U.S. would slash its emissions in half by 2030 from 2005 levels.

U.S. carbon pollution is falling, but not fast enough to meet Biden’s pledge — and stepped-up action by states, cities and businesses can get only part of the way there in the absence of stronger federal efforts.

The nations that signed the Paris deal are supposed to submit new plans by mid-February. If the world’s biggest economy isn’t contributing, it could send a signal to opponents of stringent climate action in China, India or Europe to do less.

“There are interests in all of these other countries that want to promote continued reliance on fossil fuels and a resistance to climate ambition,” said Alden Meyer, a senior associate at the climate think tank E3G.

A test of how committed other nations are to the Paris Agreement will come at COP29.

They’re expected to set a new target for global climate aid — one that could reach up to $1 trillion a year. Biden administration officials will be at the table. But with a future Trump presidency looming over the talks, other countries might be less inclined to contribute more money.