Trump signs executive order directing US withdrawal from the Paris climate agreement

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.

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,” experts said.

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

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.