Evaluating the Legality of President Trump’s Withdrawal from the UNFCCC

By: Rajeshwari Rawal
Edited by: William Liu and Michael Stewart

On January 7, 2026, President Trump issued a Presidential Memorandum [1] announcing the administration’s intention to withdraw the United States from the United Nations Framework Convention on Climate Change (UNFCCC), the Intergovernmental Panel on Climate Change (IPCC), and over 60 other international conventions and treaties. [2] This announcement comes after the Trump administration signaled its intention to withdraw from the Paris Agreement—a component of the UNFCCC—for the second time in January 2025, which went into effect on January 27 of this year. The move was executed unilaterally, without the advice or consent of Congress, eliciting potential legal challenges. The U.S. is the first and only country to withdraw from the UNFCCC, one of the most globally accepted treaties in history. [3] Trump also called for the withdrawal from other organizations related to climate change, biodiversity, and clean energy, which Secretary of State Marco Rubio called “wasteful, ineffective, or harmful.” [4]

The UNFCCC is composed of two main protocols: the Kyoto Protocol of 1997 and the Paris Agreement of 2015. [5] Sue Biniaz, former Principal Deputy Special Envoy for Climate at the US State Department and key constructor of the Paris Agreement, said that the UNFCCC’s objective is to “avoid dangerous anthropogenic (man-caused) interference with the climate system” and that controversy surrounding the Convention dates back to the Bush administration about whether the emissions target would be legally binding or not. [6] George H. W. Bush entered the Convention in 1992 with the advice and consent of the Senate, which is consistent with the Constitution’s requirements for a president to enter international treaties. [7] Bush’s early action on climate paved the way for the Clinton administration to help lead global efforts culminating in the 1997 Kyoto Protocol and eventually the 2015 Paris Climate Accords. [8] This is not the first time the U.S. has pulled out of this specific treaty; the U.S. previously left the Paris Agreement during Trump’s first term. [9]  However, according to Legal Response International, “Withdrawal from the UNFCCC itself entails far more profound legal and political consequences, given its status as the parent framework of the international climate regime and its near-universal ratification by the international community.” [10]

Can Trump Unilaterally Withdraw from the UNFCCC?

Legal ambiguity lies in joining versus withdrawing from global treaties. Since the U.S. joined the Convention over 30 years ago, the nation can withdraw from the UNFCCC under international law. Under domestic law, however, it is unclear whether the President has the authority to withdraw from a treaty without congressional action. [11] The Constitution does not explicitly specify whether Senate consent is required to leave a treaty, creating legal uncertainty surrounding the process. [12] According to Curtis Bradley, a law professor at the University of Chicago, almost all U.S. treaty withdrawals in the past 50 years have been executed unilaterally by presidents. [13] However, the law does not necessarily grant  them the power to do so. There is no concrete legal precedent on whether a president can unilaterally leave a treaty under U.S. law; in Goldwater v. Carter (1979), the Supreme Court avoided deciding whether the Senate is required to approve a president’s withdrawal from a treaty. While the Constitution is clear about the Senate’s role in ratifying a treaty, there is no clear answer on ending one. [14] There have been various attempts to codify whether this withdrawal power is exclusive to the president or if they need the support of lawmakers. [15] Other legal experts argue for the “mirror principle,” asserting that if the president needed Senate approval to enter a treaty, he would similarly need Senate consent to withdraw from it. A president’s unilateral withdrawal can be challenged if it violates congressional power or if the withdrawal implies the power to enter a new treaty. [16] Biniaz explained that U.S. law is more complicated than international rules but said that “the mainstream legal view…set forth in the Fourth Restatement of Foreign Relations law, is that the president may constitutionally withdraw the United States from a Senate-approved treaty.” [17]

Can the U.S. Re-enter the Agreement in the Future?

Though it may be possible to withdraw from the UNFCCC, it does not come without consequences. Exiting the UNFCCC adds a bureaucratic process that would need to be navigated if future administrations seek to rejoin the Paris Agreement. According to Legal Response International, “Art. 20(1) of the Paris Agreement provides that only Parties to the UNFCCC may sign and ratify the Agreement. Therefore, withdrawal from the Convention prevents any future administration from rejoining the Paris Agreement unless and until the United States first accedes to the UNFCCC.” [18] Per the Convention’s Article 23, the UNFCCC has indicated that the U.S. is welcome to rejoin in the future, but the decision will “undercut U.S. competitiveness.” [19]

Biniaz explained that pulling out of the UNFCCC might have been strategic. The Biden administration was able to easily rejoin the Paris Agreement after Trump withdrew during his first term. However, since rejoining the Paris Agreement requires being part of the UNFCCC, withdrawal reduces the ability for future administrations to do what the Biden administration did. [20] Legal experts have expressed differing opinions on the feasibility of rejoining in the future. Jean Galbraith, a professor at the University of Pennsylvania, said a future president could rejoin the convention within 90 days of a formal decision under the merit of the previous Senate approval (i.e. the original 1992 Senate approval). [21] Considering whether the original Senate approval applies is an important caveat, as being majority-Republican reduces the chance that the U.S. would re-enter the Convention if another round of congressional approval is needed. Yale Law Professor Oona Hathaway echoes this, citing a history of U.S. leaders quitting and rejoining global organizations, such as the International Labor Organization and the United Nations Educational, Scientific and Cultural Organization (UNESCO). [22] Rejoining the UNFCCC would not restore the U.S.’s prior status; as Article 25 mandates a three-year commitment, it would require a new resolution for advice and consent. [23] Joanna Depledge, a research fellow at Cambridge University’s Centre for Environment, Energy and Natural Resource Governance (CEENRG), does not believe there is a way to re-enter the climate treaties, but a future president may adopt the climate policy and rules domestically. [24] This is reflected in a 2025 Congress report on the process and potential effects of withdrawal: “Congress may choose to support policies such as emissions reductions, consistent with the PA’s goals; alternatively, Congress may choose to repeal emissions reductions and other policies after the withdrawal decision..” [25]  

Withdrawal from the UNFCCC will reduce the financial resources, expertise, and data available to the international climate science and policy community. [26] The action of withdrawing is indicative of the administration’s views on climate change. In September 2025, Secretary of Transportation Sean Duffy accused the International Civil Aviation Organization (ICAO) of “wasting critical resources on social programs or climate financing initiatives work.” Although the U.S. is the only nation withdrawing, the country is the world’s second-largest annual emitter; therefore, not being legally obligated to report national emissions may pose significant consequences. Furthermore, Biniaz said the U.S. withdrawal may make UN climate negotiations more difficult, as the U.S. has historically played a significant “broker” role. [27] “While the U.S. may no longer be a party to the Paris Agreement,” said Amnesty International's Marta Schaaf, “it still has legal obligations to protect humanity from the worsening impacts of climate change as confirmed by the International Court of Justice in its landmark 2025 Advisory Opinion.” [28]

How Would Legal Redress be Considered?

A lawsuit against this withdrawal can be difficult for several reasons. Suing the administration can pose challenges if the withdrawal has not been formally instituted [29], which aligns with the fact that Trump’s memo did not specify whether or not his administration will submit a formal notice of termination to the UN. [30] While Congress may pass a bill stating that congressional approval is required before withdrawal, this outcome is unlikely given a majority-Republican Congress. It is also possible that the courts treat lawsuits as a political question rather than a purely legal one, as the Supreme Court “traditionally gives deference to presidents on matters of foreign affairs.” [31]

Furthermore,  the environmental and economic impacts are numerous and hard to isolate.

Loss and damage, which refers to the impact a country may sustain due to climate change, is a subject of debate within the UNFCCC. [32] It would be difficult for third parties to sue for harm because climate change’s wide-ranging impacts technically affect everyone. That being said, one caveat that can be introduced is the disproportionate harm certain parties or areas may face. [33] States may also struggle to sue for environmental damage since the UNFCCC does not contain specific obligations to reduce emissions. [34] Moreover, the extent of loss and damage may be inaccurately outlined because previous economic models failed to include the potential for net negative climate impacts resulting from a withdrawal. The uncounted impacts, per the 2025 congressional report on the process and effects of withdrawal, include “the economic effects from extreme heat events, droughts, flooding, and agricultural losses, among others, and how they would change with U.S. participation or withdrawal from the [Paris Agreement].” [35]

Climate change is a globally recognized phenomenon with documented adverse effects. Whether the U.S. decides to rejoin the UNFCCC or the Paris Agreement in the future—and whether the legal process admits future administrations to do so—it is essential to consider the environmental impacts of this withdrawal as well as the nation’s place in global politics and agreements moving forward. 

Notes:

1. Donald Trump, “Withdrawing the United States from International Organizations, Conventions, and Treaties that Are Contrary to the Interests of the United States,” January 7, 2026, https://www.whitehouse.gov/presidential-actions/2026/01/withdrawing-the-united-states-from-international-organizations-conventions-and-treaties-that-are-contrary-to-the-interests-of-the-united-states/. 

2. Carbon Direct, “The United States’ unconventional withdrawal from the UNFCCC,” January 15, 2026, https://www.carbon-direct.com/insights/the-united-states%E2%80%99-unconventional-withdrawal-from-the-unfccc. 

3. Carbon Direct, “The United States’ unconventional withdrawal from the UNFCCC”

4. Marco Rubio, Secretary of State, “Withdrawal from Wasteful, Ineffective, or Harmful International Organizations,” January 7, 2026, https://www.state.gov/releases/2026/01/withdrawal-from-wasteful-ineffective-or-harmful-international-organizations/.

5. Carbon Brief, “What Trump’s US exit from UNFCCC and IPCC could mean for climate action,” January 9, 2026, https://www.carbonbrief.org/qa-what-trumps-us-exit-from-unfccc-and-ipcc-could-mean-for-climate-action/.

6. CleanLaw, Sue Biniaz, “Legal Implications of the US Withdrawal from the UNFCCC,” January 26, 2026, https://eelp.law.harvard.edu/legal-implications-of-the-us-withdrawal-from-the-unfccc/.

7. Carbon Direct, “The United States’ unconventional withdrawal from the UNFCCC”

8. National Security Archive, “Trump’s Withdrawal from UN Climate Body Breaks Bipartisan Consensus on Multilateral Efforts,” January 15, 2026, https://nsarchive.gwu.edu/briefing-book/climate-change-transparency-project/2026-01-15/trumps-withdrawal-un-climate-body. 

9. Carbon Brief, “What Trump’s US exit from UNFCCC and IPCC could mean for climate action”

10. Legal Response International, “The legality of the United States’ withdrawal from the UNFCCC,” January 13, 2026, https://legalresponse.org/the-legality-of-the-united-states-withdrawal-from-the-unfccc/.

11. Legal Response International, “The legality of the United States’ withdrawal from the UNFCCC”

12. Carbon Brief, “What Trump’s US exit from UNFCCC and IPCC could mean for climate action”

13. Sara Schonhardt, POLITICO, “Trump erased the Senate’s 1992 vote on a climate treaty. Can he do that?” January 20, 2026, https://www.eenews.net/articles/trump-erased-the-senates-1992-vote-on-a-climate-treaty-can-he-do-that/.

14. Sara Schonhardt, POLITICO, “Trump erased the Senate’s 1992 vote on a climate treaty. Can he do that?”

15. Karen Sokol, Congress, “Congress and the Scope of the President’s Article II Foreign Policy Authorities,” May 2, 2025, https://www.congress.gov/crs-product/R48524#_Toc197353385. 

16. Legal Response International, “The legality of the United States’ withdrawal from the UNFCCC”

17. Sue Biniaz, CleanLaw, “Legal Implications of the US Withdrawal from the UNFCCC”

18. Legal Response International, “The legality of the United States’ withdrawal from the UNFCCC”

19. Carbon Direct, “The United States’ unconventional withdrawal from the UNFCCC”

20. Sue Biniaz, CleanLaw, “Legal Implications of the US Withdrawal from the UNFCCC”

21. Carbon Brief, “What Trump’s US exit from UNFCCC and IPCC could mean for climate action”

22. Carbon Brief, “What Trump’s US exit from UNFCCC and IPCC could mean for climate action”

23. Legal Response International, “The legality of the United States’ withdrawal from the UNFCCC”

24. Legal Response International, “The legality of the United States’ withdrawal from the UNFCCC”

25. Jonathan Haskett, Congress, “U.S. Withdrawal from the Paris Agreement: Process and Potential Effects,” April 14, 2025, https://www.congress.gov/crs-product/R48504 

26. Carbon Direct, “The United States’ unconventional withdrawal from the UNFCCC”

27. Carbon Brief, “What Trump’s US exit from UNFCCC and IPCC could mean for climate action”

28. Amnesty International, “Global: US withdrawal from landmark Paris Climate Agreement threatens “a race to the bottom,” January 27, 2026, https://www.amnesty.org/en/latest/news/2026/01/global-us-withdrawal-from-landmark-paris-climate-agreement-threatens-a-race-to-the-bottom/ 

29. Sara Schonhardt, POLITICO, “Trump erased the Senate’s 1992 vote on a climate treaty. Can he do that?”

30. Dharna Noor, The Guardian, “Trump’s move to pull US from key UN climate treaty may be illegal, experts say,” January 12, 2026, https://www.theguardian.com/us-news/2026/jan/12/trump-un-climate-treaty-unfccc 

31. Sara Schonhardt, POLITICO, “Trump erased the Senate’s 1992 vote on a climate treaty. Can he do that?”

32. Jonathan Haskett, Congress, “U.S. Withdrawal from the Paris Agreement: Process and Potential Effects”

33. Sara Schonhardt, POLITICO, “Trump erased the Senate’s 1992 vote on a climate treaty. Can he do that?”

34. Sara Schonhardt, POLITICO, “Trump erased the Senate’s 1992 vote on a climate treaty. Can he do that?”

35. Jonathan Haskett, Congress, “U.S. Withdrawal from the Paris Agreement: Process and Potential Effects”

Bibliography:

Amnesty International. “Global: US Withdrawal From Landmark Paris Climate Agreement Threatens ‘A Race to the Bottom,’” January 27, 2026. https://www.amnesty.org/en/latest/news/2026/01/global-us-withdrawal-from-landmark-paris-climate-agreement-threatens-a-race-to-the-bottom/.

Biniaz, Sue. “CleanLaw — Legal Implications of the US Withdrawal From the UNFCCC – Environmental and Energy Law Program,” n.d. https://eelp.law.harvard.edu/legal-implications-of-the-us-withdrawal-from-the-unfccc/.

Haskett, Jonathan. “U.S. Withdrawal from the Paris Agreement: Process and Potential Effects.” Congress, April 2025. https://www.congress.gov/crs-product/R48504.

Noor, Dharna. “Trump’s Move to Pull US From Key UN Climate Treaty May Be Illegal, Experts Say.” The Guardian, February 10, 2026. https://www.theguardian.com/us-news/2026/jan/12/trump-un-climate-treaty-unfccc.

Schonhardt, Sara. “Trump Erased the Senate’s 1992 Vote on a Climate Treaty. Can He Do That?” E&E News by POLITICO, January 20, 2026. https://www.eenews.net/articles/trump-erased-the-senates-1992-vote-on-a-climate-treaty-can-he-do-that/.

Sokol, Karen. “Congress and the Scope of the President’s Article II Foreign Policy Authorities.” Congress. Congress, May 2025. https://www.congress.gov/crs-product/R48524#_Toc197353385.

Staff, Carbon Brief. “Q&Amp;A: What Trump’s US Exit From UNFCCC and IPCC Could Mean for Climate Action.” Carbon Brief, February 10, 2026. https://www.carbonbrief.org/qa-what-trumps-us-exit-from-unfccc-and-ipcc-could-mean-for-climate-action/.

Staff, Legal Response International. “The Legality of the United States’ Withdrawal From the UNFCCC,” January 2026. https://legalresponse.org/the-legality-of-the-united-states-withdrawal-from-the-unfccc/.

Chimdi Obienu, Rory Jacobson. “The United States’ Unconventional Withdrawal From the UNFCCC | Carbon Direct,” n.d. https://www.carbon-direct.com/insights/the-united-states%E2%80%99-unconventional-withdrawal-from-the-unfccc.

Donald Trump. “Withdrawing the United States From International Organizations, Conventions, and Treaties That Are Contrary to the Interests of the United States,” January 7, 2026. https://www.whitehouse.gov/presidential-actions/2026/01/withdrawing-the-united-states-from-international-organizations-conventions-and-treaties-that-are-contrary-to-the-interests-of-the-united-states/.

Edited by Rachel Santarsiero. National Security Archive. “Trump’s Withdrawal From UN Climate Body Breaks Bipartisan Consensus on Multilateral Efforts,” January 15, 2026. https://nsarchive.gwu.edu/briefing-book/climate-change-transparency-project/2026-01-15/trumps-withdrawal-un-climate-body.

Marco Rubio. “Withdrawal From Wasteful, Ineffective, or Harmful International Organizations - United States Department of State,” January 8, 2026. https://www.state.gov/releases/2026/01/withdrawal-from-wasteful-ineffective-or-harmful-international-organizations/.