WASHINGTON — President Donald Trump says he will again withdraw the United States, a top carbon polluting nation, from the landmark Paris climate agreement, dealing a blow to worldwide efforts to combat global warming and once again distancing the U.S. from its closest allies.

The White House announcement, which came as Trump was sworn in Monday to a second term, echoed Trump’s actions in 2017, when he announced that the U.S. would abandon the global Paris accord. The pact is aimed at limiting long-term global warming to 2.7 degrees Fahrenheit (1.5 degrees Celsius) above pre-industrial levels or, failing that, keeping temperatures at least well below 3.6 degrees Fahrenheit (2 degrees Celsius) above pre-industrial levels.

The 2015 Paris agreement is voluntary and allows nations to provide targets to cut their own emissions of greenhouse gases from the burning of coal, oil and natural gas. Those targets are supposed to become more stringent over time, with countries facing a February 2025 deadline for new individual plans. The outgoing Biden administration last month offered a plan to cut U.S. greenhouse gas emissions by more than 60% by 2035.

CEO of the European Climate Foundation Calls Departure ‘Unfortunate’

Laurence Tubiana, CEO of the European Climate Foundation and a key architect of the Paris agreement, called the planned U.S. withdrawal unfortunate but said action to slow climate change “is stronger than any single country’s politics and policies.”

The global context for Trump’s action is “very different to 2017,” Tubiana said, adding that “there is unstoppable economic momentum behind the global transition, which the U.S has gained from and led but now risks forfeiting.”

The International Energy Agency expects the global market for key clean energy technologies to triple to more than $2 trillion by 2035, she said.

“The impacts of the climate crisis are also worsening. The terrible wildfires in Los Angeles are the latest reminder that Americans, like everyone else, are affected by worsening climate change,” Tubiana said.

Gina McCarthy, who served as White House climate adviser under President Joe Biden, a Democrat, said that if Trump, a Republican, “truly wants America to lead the global economy, become energy independent and create good-paying American jobs,” then he must “stay focused on growing our clean energy industry. Clean technologies are driving down energy costs for people all across our country.”

World Is Hotter

The world is now long-term 2.3 degrees Fahrenheit (1.3 degrees Celsius) above mid-1800s temperatures. Most but not all climate monitoring agencies said global temperatures last year passed the warming mark of 2.7 degrees Fahrenheit, and all said it was the warmest year on record.

The withdrawal process from the Paris accord takes one year. Trump’s previous withdrawal took effect the day after the 2020 presidential election, which he lost to Biden.

While the first Trump-led withdrawal from the landmark U.N. agreement — adopted by 196 nations — shocked and angered nations across the globe, “not a single country followed the U.S. out the door,” said Alden Meyer, a longtime climate negotiations analyst with the European think tank E3G.

Instead, other nations renewed their commitment to slowing climate change, along with investors, businesses, governors, mayors and others in the U.S., Meyer and other experts said.

Still, they lamented the loss of U.S. leadership in global efforts to slow climate change, even as the world is on track to set yet another record hot year and has been lurching from drought to hurricane to flood to wildfire.

“Clearly America is not going to play the commanding role in helping solve the climate crisis, the greatest dilemma humans have ever encountered,″ said climate activist and writer Bill McKibben. “For the next few years the best we can hope is that Washington won’t manage to wreck the efforts of others.”

About half of Americans “somewhat” or “strongly” oppose U.S. action to withdraw from the climate accord, and even Republicans aren’t overwhelmingly in favor, according according to a poll from The Associated Press-NORC Center for Public Affairs Research. Only about 2 in 10 U.S. adults “somewhat” or “strongly” in favor of withdrawing from the Paris agreement, while about one-quarter are neutral.

Opposition Comes Mostly From Democrats

Much of the opposition to U.S. withdrawal comes from Democrats, but Republicans display some ambivalence as well. Slightly less than half of Republicans are in favor of withdrawing from the climate accord, while about 2 in 10 are opposed.

China several years ago passed the United States as the world’s largest annual carbon dioxide emitting nation. The U.S. — the second biggest annual carbon polluting country — put 4.9 billion metric tons of carbon dioxide in the air in 2023, down 11% from a decade earlier, according to the scientists who track emissions for the Global Carbon Project.

But carbon dioxide lasts in the atmosphere for centuries, so the United States has put more of the heat-trapping gas that is now in the air than any other nation. The U.S. is responsible for nearly 22% of the carbon dioxide put in the atmosphere since 1950, according to Global Carbon Project.

While global efforts to fight climate change continued during Trump’s first term, many experts worry that a second Trump term will be more damaging, with the United States withdrawing even further from climate efforts in a way that could cripple future presidents’ efforts. With Trump, who has dismissed climate change, in charge of the world’s leading economy, those experts fear other countries, especially China, could use it as an excuse to ease off their own efforts to curb carbon emissions.

Simon Stiell, the U.N. climate change executive secretary, held out hope that the U.S. would continue to embrace the global clean energy boom.

“Ignoring it only sends all that vast wealth to competitor economies, while climate disasters like droughts, wildfires and superstorms keep getting worse,” Stiell said. “The door remains open to the Paris Agreement, and we welcome constructive engagement from any and all countries.”