Trump, with typical pageantry — which included a Marine Corps jazz warmup band — revealed his decision during a speech in the White House Rose Garden.
"As of today, the United States will cease all implementation of the non-binding Paris accord and the draconian financial and economic burdens the agreement imposes on our country," Trump said, adding "I cannot in good conscience support a deal that punishes the United States."
Trump said that the US would begin negotiations to "re-enter the Paris accord or a really entirely new transaction on terms that are fair to the United States."
"So we're getting out but we'll start to negotiate and we will see if we can make a deal that's fair," Trump said. "And if we can, that's great. And if we can't, that's fine."
Trump repeatedly framed the Paris agreement Thursday as an unfair deal for the US that would negatively impact the economy and bring about "a massive redistribution of United States wealth to other counties." The comments echo Trump's frequent criticism of the climate deal while he was on the campaign trail, and the withdrawal is sure to appeal to voters who took to his anti-globalist message.
It was unclear, however, how a renegotiation process might play out. Shortly after Trump's announcement, France, Germany, and Italy issued a joint statement saying the Paris agreement cannot be renegotiated. And during a White House press briefing Thursday afternoon, an official speaking on background would say only that the "negotiation process will be determined by the president going forward."
Officials nevertheless described Trump as "sincere" in his desire to renegotiate, but said economics was the bottom line in his decision to withdraw.
"When the president looked at the provisions of the agreement, he asked what is going to be the impact on the American worker, that was the bottom line," an official said.
White House officials would not answer reporters' questions about whether or not Trump believes climate change is real, calling the question "off topic."
By the rules of the 2015 agreement, Trump cannot formally notify the United Nations of his intention to withdraw until three years of it coming into force — and then must wait another year for the withdrawal to take effect. That would be two days after the next US presidential election in 2020.
The announcement of the withdrawal comes after months of internal debate within Trump's family and administration. Many conservatives, including Environmental Protection Agency head Scott Pruitt, wanted out of the deal. By withdrawing, Trump will be parting with ExxonMobil, the Pope, and his daughter Ivanka — as well as European leaders who had reaffirmed their commitment to the deal in May at the Group of Seven (G7) meeting in Sicily. There, German chancellor Angela Merkel called climate discussions with Trump "very difficult, if not to say very dissatisfying."
Under the Paris Agreement, the Obama administration had pledged to cut emissions within a decade by at least 26% compared to 2005 levels. A rollback in clean power plant rules that Trump ordered in March had already lowered the nation's chances of reaching that goal.
"The real consequence of withdrawal would be a catastrophe for US leadership and credibility in the world," retired US Navy Admiral David Titley, a climate scientist, told BuzzFeed News. Actual US commitments under the agreement only limited global warming a small amount, he noted, "but we are the world's second largest economy, so it actually does matter if the President does walk away, there is some damage to the climate."
What's more, he added, damaging the Paris accord diplomatically gets the world off track to limit climate change in this century: "I won't be alive then, but I'd be very surprised if we aren't over 3 degrees [5.4 degrees Fahrenheit] warmer in 2100, probably up 4 degrees [7.2 degrees], which will be disastrous for the world."
An array of environmental groups, politicians, and companies also criticized the withdrawal Thursday. Minutes after Trump began speaking, former President Obama called the Paris agreement an example of "steady, principled American leadership on the world stage."
"The nations that remain in the Paris Agreement will be the nations that reap the benefits in jobs and industries created," Obama continued. "I believe the United States of America should be at the front of the pack."
Former Democratic presidential candidate Hillary Clinton called the move "a historic mistake."
"The world is moving forward together on climate change. Paris withdrawal leaves American workers & families behind," she said in a tweet.
Sen. Bernie Sanders tweeted that "withdrawing from the Paris climate agreement would be a horrific mistake." Sen. Charles Schumer said in a statement that the decision to withdraw "is a devastating failure of historic proportions" that "puts America last in recognizing science, in being a world leader and protecting our shore line, our economy and our planet."
"Future generations will look back on President Trump's decision as one of the worst policy moves made in the 21st century because of the huge damages to our economy, our environment, and our geopolitical standing," Schumer said.
California Gov. Jerry Brown — who has made fighting climate change a key part of his administration and legacy — said that Trump "has absolutely chosen the wrong course" and is "wrong on the facts."
"California will resist this misguided and insane course of action," Brown said in a statement. "Trump is AWOL but California is on the field, ready for battle."
In the minutes before Trump announced the pull out, the Sierra Club tweeted congratulations to "President Bannon."
Center for Biological Diversity executive director Kierán Suckling called the withdrawal "reckless" and said it "took a giant step toward turning our country into a rogue nation."
Elon Musk, CEO of Tesla and SpaceX, made good on his promise to step down as an adviser to the president if the US withdrew, tweeting Thursday afternoon that he was "departing presidential councils. Climate change is real. Leaving Paris is not good for America or the world."
In a statement to BuzzFeed News, a spokesperson for Amazon said that the online retailer "continues to support the Paris climate agreement and action on climate change."
"We believe that robust clean energy and climate policies can support American competitiveness, innovation, and job growth," the spokesperson said. "We remain committed to putting our scale and inventive culture to work in ways that are good for the environment and our customers."
Grant Reid, CEO of candy maker Mars, said in a statement his company "stands by the Paris Climate Agreement." Jeff Immelt, CEO of General Electric, tweeted that he was "disappointed with today's decision on the Paris Agreement. Climate change is real." Sundar Pichai, CEO of Google, tweeted that he was disappointed but his company "will keep working hard for a cleaner, more prosperous future for all."
And in a statement to BuzzFeed News, cereal company General Mills said it was "disappointed" by the withdrawal and remained committed to "addressing challenges related to climate change."
Anticipating criticism, Trump argued in his speech Thursday that the US "will continue to be the cleanest and most environmentally friendly country on Earth."
"We'll be the cleanest," he said. "We're going to have the cleanest air, the cleanest water, we will be environmentally friendly but we're not going to put our businesses out of work and we're not going to lose our jobs."
Thursday afternoon, a White House official speaking on background to explain the decision said "there's no question the Paris Agreement would be the nail in the coffin for US manufacturing.
At the Pentagon, which for years has spoken of climate change as a threat that expands from the Arctic to the Middle East, Thursday's announcement was met with a notable silence. Privately, some defense officials seemed concerned about how the decision would affect the world's trust in America's word. For a military which makes agreements across battlefields with Iraqi troops, Afghan politicians, and even allied counterparts, trustworthiness is key.
Still others were confused about what this decision means for how the US military will approach what it has described as a threat spurred by climate change.
"What is our policy?" one defense official asked.
In his comments Thursday, Trump made no mention of climate change as a potential national security threat.
The climate accord went into force worldwide in November, days ahead of the US election, and has been ratified by 147 nations responsible for more than 55% of the world's greenhouse gasses. It pledges to limit emissions and promises financial aid to developing nations so they can build low-emissions energy industries.
As Trump spoke Thursday, the European Union and China were holding a summit in Brussels, where they will reaffirm limits to greenhouse gas emissions and plans to pursue clean energy investments worldwide. Chinese Premier Li Keqiang told reporters in Berlin that dealing with global warming was an "international responsibility," according to the Associated Press, and that China — the world's largest economy and emitter of greenhouse gasses — intended to honor the commitments it made in the Paris agreement.
A leaked version of a joint EU-China statement released ahead of Trump's appearance said that those two parties, "confirm their commitments under the historic 2015 Paris Agreement and step up their co-operation to enhance its implementation."
In Antarctica, meanwhile, an ice shelf the size of Delaware is about to drop off the frozen continent, according to researchers at the United Kingdom's Swansea University. The calving of the Larsen C Ice Shelf will birth one of the world's largest icebergs, and will open the door to more ice loss from the Antarctic Peninsula, one of the most rapidly-warming places on Earth.
As early as 2010, Secretary of Defense Jim Mattis publicly called climate change a national security threat.
“Climate change is impacting stability in areas of the world where our troops are operating today,” Mattis wrote in unpublished testimony provided to the Senate Armed Services Committee in the run up to his confirmation hearing, according to a March ProPublica report.
And in 2010, Mattis, who was then a general and commander of the Joint Forces Command, released a report that listed climate change as a national security threat. In the foreword of the report, Mattis called climate change one of the “trends that remind us we must stay alert to what is changing in the world if we intend to create a military as relevant and capable as we possess today.”
Nancy Youssef contributed to this report.