The Trump administration’s all-out assault on climate and environmental policy is nothing new—it has been a defining feature of the president’s agenda since his first term. And yet, Trump’s decision to pull the U.S. from the United Nations Framework Convention on Climate Change (UNFCCC) still shocked the world on Wednesday.

Trump signed a sweeping executive order to effectively withdraw the U.S. from 66 international organizations that “no longer serve American interests,” according to the White House. That includes the UNFCCC, the foundational treaty and legal framework for global cooperation to combat climate change. The move will leave the U.S. as the only country in the world not part of the treaty.

The executive order also pulled the U.S. from the Intergovernmental Panel on Climate Change (IPCC)—the leading global scientific body studying climate change—and more than a dozen other international partnerships focused on climate, conservation, natural resources, energy, and sustainability.

“At a time when climate change impacts are accelerating—whether it’s ever-worsening fire seasons, more intense hurricanes, or prolonged droughts—choosing withdrawal over leadership is shortsighted and profoundly irresponsible,” the leaders of the House Sustainable Energy and Environment Coalition (SEEC) said in an emailed statement. “Climate change does not respect borders, and we cannot address this crisis alone.”

How we got here

This move was a long time coming. Trump has consistently framed international climate agreements as constraints on U.S. sovereignty and economic growth. His withdrawal from the Paris Agreement—an integral part of the UNFCCC—in 2017 signaled broader opposition to UN climate architecture.

The U.S. rejoined the Paris Agreement in 2021 under the Biden administration, but Trump withdrew again on the first day of his second term.

Over the course of 2025, the Trump administration continued to distance itself from global climate leadership, rescinding outstanding pledges to climate funds, canceling support for international clean energy initiatives while financing major fossil fuel projects, and refusing to send a delegation to COP30 (the 2025 UN climate summit in Belém, Brazil).

Meanwhile, the administration’s attacks on domestic climate policy have been just as aggressive. Within the past year, it has dismantled a slew of climate and pollution regulations, declared a fictitious “National Energy Emergency” to expedite the permitting process for fossil fuel projects while curtailing the growth of the renewable energy sector, and overhauled how the government responds to climate-driven natural disasters.

These are just some of the steps the Trump administration has taken to transform the U.S. from an active leader in global climate action to a dissenter. Now that the country is withdrawing from the UNFCCC, it will be harder than ever for a future administration to reverse course.

What the withdrawal means

Once the U.S. files a formal notice with the United Nations, the treaty withdrawal will take a year to go into effect. After that, the U.S. will no longer take part in COP negotiations or be bound by the treaty’s emissions reporting obligations. This will strip the U.S. of its formal influence over global climate rules, leaving those decisions to the rest of the world.

In a statement, Simon Stiell, executive secretary of the UNFCC, said “the doors remain open” for the U.S. to reenter the treaty in the future, as it did with the Paris Agreement under Biden.

But some legal scholars warn that reversing the withdrawal may not be so simple. According to DT Vollmer, an associate lawyer at the Canadian climate and energy law firm Resilient LLP, rejoining the UNFCCC may be extremely difficult without a two-thirds Senate majority. This is “a challenging bar to meet for any administration in an age when the 100-member Senate is generally held by only a small majority,” Vollmer writes.

Even as the Trump administration works to isolate the U.S. from global climate action, it cannot isolate the country from the impacts of climate change. Rising temperatures will continue to fuel deadly, costly extreme weather events, strain infrastructure, disrupt agriculture, and harm public health. Americans can only hope the rest of the world will remain committed to mitigating the damage.