Withdrawing from the UN Climate Negotiations: Cascading Mistakes from the Trump Administration

Withdrawing from the UN Climate Negotiations: Cascading Mistakes from the Trump Administration
By Rachel Westrate

No one was particularly shocked when one of President Trump’s first acts upon returning to office on January 20, 2025 was to sign an executive order directing the State Department to withdraw from the Paris Agreement on climate change. After all, Trump pulled out of the Agreement during his first term, only for the United States to re-join the Agreement under the leadership of President Joe Biden in 2021. Now, a new January 7, 2026 Presidential Memorandum demands the U.S. withdraw from the parent treaty of the Paris Agreement—the United Nations Framework Convention on Climate Change (UNFCCC)—as well as 30 other United Nations entities and 35 non-U.N. organizations.

Withdrawal from the UNFCCC will make the United States the only U.N. member state that does not participate in the international climate treaty. For those who care about the health of our planet, U.S. foreign relations, or general international order, this move is deeply troubling. It is unsurprising that this Administration would take such drastic measures to prevent the United States from participating in the international climate conversation. But it is also a profoundly un-strategic move by the Trump Administration, given both their keen interest in international energy trends and ongoing domestic litigation against state climate laws.

This blog will provide a brief background on the international climate regime, summarize the legal speculations around the U.S. withdrawal from the UNFCCC, and discuss the implications for Trump’s international and domestic priorities.

Background: the UNFCCC & International Climate Negotiations

The United States was the first industrialized country and the fourth country overall to join the UNFCCC, after ratification by the Senate and signature by Republican President George H.W. Bush. As the first and still the most significant multinational climate treaty, the UNFCCC establishes the framework under which countries cooperate to address climate change. That framework entails an annual Conferences of the Parties (COPs) where UNFCCC member states negotiate “legal instruments” or “protocols” to help achieve the UNFCCC’s goal of stabilizing greenhouse gas concentrations in our atmosphere.

Countries have negotiated and adopted two main instruments under the UNFCCC: the 1997 Kyoto Protocol and the 2015 Paris Agreement. The United States signed the Kyoto Protocol in 1998. But the Senate never ratified that treaty, because it called for binding emissions reductions in developed countries without imposing similar obligations on developing countries (the Byrd-Hagel Resolution expressing the Senate’s distaste for Kyoto passed with a vote of 95 – 0). As soon as it became clear that the U.S., the largest annual emitter of greenhouse gases at the time, would not ratify the Kyoto Protocol, negotiations began anew under the UNFCCC to work toward an agreement that would be more universally accepted.

The result was the Paris Agreement. Paris, unlike Kyoto, does not mandate emission cuts from any country. Instead, it establishes a cooperative framework under which countries work together to limit warming to under 2 degrees Celsius by creating and submitting plans to reduce national greenhouse gas emissions (called Nationally Determined Contributions, or NDCs). Parties to the Paris Agreement must also submit annual reports on their greenhouse gas emissions. Aside from those reporting obligations, though, the Paris Agreement is an entirely voluntary instrument, relying on bottom-up, domestic action within countries to address climate change—an evolution from the top-down, mandatory emissions reductions required under the Kyoto Protocol. 195 member countries to the UNFCCC adopted the Paris Agreement in 2015, and President Obama used his executive authority to ratify the Agreement on behalf of the United States in 2016.

President Trump withdrew from the Paris Agreement upon taking office, with the U.S. withdrawal becoming effective in 2020. The U.S. then rejoined under President Biden in 2021, only to deposit a notice of withdrawal from the Paris Agreement with the Office of the U.N. Secretary General on January 27, 2025, shortly into Trump’s second term. The U.S. withdrawal will become effective one year from that date, on January 27, 2026. (For a full timeline and guide, see NRDC’s Paris Climate Agreement: Everything You Need to Know).

Legal Implications of Withdrawing from the UNFCCC

While a President can unilaterally withdraw from the Paris Agreement (given that President Obama unilaterally entered it in 2016), it is a matter of legal debate whether the same is true of the UNFCCC. During the last Trump Administration, legal scholars built a body of work exploring this question. Professor Harold Koh published a 2018 essay arguing the President does not have the authority to unilaterally terminate or withdraw from any international agreement. Professor Jean Galbraith argued in a law review article that if a President unilaterally withdraws from a Senate-ratified treaty, the action does not negate the Senate’s initial advice and consent, and a future President could unilaterally rejoin the same treaty without seeking Senate re-authorization. But there is no Supreme Court precedent on unilateral withdrawal or rejoining of Senate-ratified treaties, and so the question remains up for debate.

This time around, the climate legal community has been quick to opine on whether or not the President can withdraw from the Framework Convention without consulting Congress and what withdrawal might mean for U.S. participation under a more climate-friendly future administration. Former U.S. climate negotiator Sue Biniaz and Professor Galbraith explained the international and domestic process of withdraw and reiterated their theory of rejoining without additional Senate consent. Carbon Brief collected experts’ thoughts on withdrawal, rejoining, and practical changes to the climate negotiations absent U.S. participation, detailing the legal uncertainty of the move and analogizing to other international organizations the U.S. has left and rejoined. Law Professor Dan Farber suggested that the U.S. may not even need to be a party to the UNFCCC to play a role in the Paris Agreement. The Executive Secretary of the UNFCCC issued a statement on Thursday, January 8^th noting that “the doors remain open for the US to reenter in the future”—but what that looks like legally is anyone’s guess.

We have yet to see if any litigation will be filed against the Trump Administration for this latest action—and whether any potential litigation may provide us with a definitive answer.

International Implications

By withdrawing from Paris, the United States will no longer be required to submit an NDC, nor will it submit yearly reports on domestic emissions (although, despite the withdrawal not officially occurring until 2026, the Trump Administration failed to submit the data in 2025). U.S. funding to the international climate organizations has ceased, including the UNFCCC and the Green Climate Fund (GCF).

But the U.S. withdrawal also means it can no longer participate in negotiations as a party and does not have the right to vote, which in turn means the U.S. will no longer have a say on topics that seem central to the Trump Administration’s policy agenda. In recent years, multinational climate negotiations have increasingly seen calls for an international roadmap to phase out fossil fuels, which would jeopardize the Administration’s goal of exporting domestic fossil fuels. The U.S. has already used its influence in other spheres to weaken environmental language coming out of the U.N., and it seems strange the Administration is willing to so easily give up the opportunity to thwart international climate progress.

Pulling out of the UNFCCC also means that future decisions and agreements will not reflect the interests or priorities of the United States—and are likely to be more heavily influenced by other big players. That includes China, which is rapidly expanding its global influence and renewable energy markets, and the European Union, which usually favors a more top-down, regulatory approach to addressing climate change in comparison to U.S.-favored market-based, voluntary approaches (for evidence of the U.S.-EU tension, see recently released State Department papers detailing the lead up to the Paris summit).

But what is bad for the Trump Administration could well be good for people and the planet. The lack of the presence of the United States, and particularly the Trump Administration, could leave room for more innovation and progress in the climate talks, as U.S. positions (in both Republican and Democratic Administrations) against mandatory emissions reductions, climate finance contributions, and phase-out of fossil fuel subsidies have frustrated negotiations in the past. While deep divides remain among countries party to the UNFCCC and the Paris Agreement, the power vacuum left by the U.S. may create an opportunity for new players and alliances to support ideas that would have previously been considered dead on arrival.

The folly of the Trump Administration and the potential for new movement in the climate negotiations, however, are unlikely to outweigh the staggering loss of the U.S. withdrawing from the UNFCCC. A climate process without the largest historical emitter of greenhouse gases, the second largest current emitter of GHGs, and the world’s largest economy can only achieve so much when climate change is a collective action problem. And while the international climate negotiations process will not break down without the participation of the U.S., the country has been a major player for the last thirty years and often a broker of compromise.

Beyond this Administration, if decisions and agreements coming out of the COPs are not reflective of U.S. priorities and political landscape, it may also make it more difficult for the U.S. to rejoin in the future. President Obama was able to unilaterally join the Paris Agreement because domestic legislation and authority already existed to allow the country to comply with obligations under the agreement—and U.S. negotiators worked to design the agreement with this in mind. Even in the final hours of the negotiations over the Paris Agreement, State Department lawyers had to lobby for a one-word change that threatened the U.S.’s ability to support the outcome. Without U.S. input and pressure, it is possible for the negotiations to produce outcomes that even a climate-friendly Administration would be unable to rejoin without action from the Congress.

Domestic Implications: Inconsistencies in Ongoing Litigation

Perhaps especially cofounding is the Trump Administration’s decision to withdraw from the UNFCCC while relying on U.S. membership in the organization to justify ongoing domestic litigation against state climate laws. Both Vermont and New York passed climate superfund acts in 2024, which require payments from entities that emitted large amounts of greenhouse gases in the past several decades to help pay for climate adaptation projects in the states. On May 1, 2025, the United States of America and the United States Environmental Protection Agency filed suit against Vermont and New York, claiming (among other things) that the climate superfund laws are preempted by the federal government’s foreign affairs power.

The basis for the lawsuits overall is fundamentally flawed, given that the climate superfund laws do not regulate greenhouse gas emissions, states have both a right and responsibility to protect their citizens and environment, and both the UNFCCC and Paris Agreement support subnational action. But putting aside the Trump Administration’s mischaracterization of the laws and misunderstanding of national and international law, withdrawing from the UNFCCC fatally undermines their arguments that the federal government’s participation in the UNFCCC is what preempts states from acting on climate.

In its complaint against Vermont, the United States argues that “[b]y adopting the Framework Convention, the federal government undertook to formulate foreign policy” on greenhouse gases. It characterizes Trump’s decision to withdraw from the Paris Agreement as a foreign policy decision because Trump wants to “put the interests of the American people first in negotiating the terms of any future treaty to implement the” UNFCCC. The Vermont Act, the brief claims, “interferes with… the United States’ participation in the” UNFCCC. In a subsequent brief, the Department of Justice also argues that state climate superfund statutes conflict with the 1987 Global Climate Protection Act, in which Congress directed the President to “‘work towards multilateral agreements’ on greenhouse gas emissions.”

By withdrawing from the UNFCCC, the Trump Administration has pulled the rug out from under those arguments. The Administration has ensured that the United States will not be negotiating any future treaty to implement the UNFCCC or to carry out its obligations under the Global Climate Protection Act. By abdicating its role in formulating the American climate policy, the Trump Administration may well have cleared the way for states to fill the void.

The news from January 7^th is, without a doubt, a major setback for the international climate negotiations. But it is also, as U.N. climate chief Simon Steill said, a “colossal own goal” for the United States and the Trump Administration in their quest to influence international and domestic climate priorities in the coming years.