U.S. withdraws from the IPCC, UNFCCC and other international climate science bodies (Jan. 2026)

Case

On Jan. 7, 2026 President Trump ordered the U.S. to withdraw from 66 international organizations, including the Intergovernmental Panel on Climate Change (IPCC), the UN climate treaty body (UNFCCC) and the biodiversity panel IPBES, and Treasury announced the next day the U.S. was leaving the Green Climate Fund. The U.S. had already begun leaving the Paris Agreement, effective Jan. 27, 2026. Scientists say the exit reduces U.S. input to global assessments and shared emissions inventories.

The January 2026 withdrawals
On Jan. 7, 2026 President Trump issued a memorandum withdrawing the U.S. from 66 international organizations, conventions and treaties "contrary to the interests of the United States": 35 non-UN entities and 31 UN entities.
The list includes the UNFCCC (the UN climate treaty body), the Intergovernmental Panel on Climate Change (IPCC) and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). The memo follows a review ordered by Executive Order 14199 of Feb. 4, 2025.
On Jan. 8 the Treasury Department announced the U.S. would also leave the Green Climate Fund, the world's largest climate fund.
Eos reports the order will make the U.S. the only country in the world that does not participate in the UNFCCC.
The U.S. had already announced its withdrawal from the Paris Agreement in January 2025, effective Jan. 27, 2026.
UNFCCC Executive Secretary Simon Stiell said the step back from global leadership, climate cooperation and science can only harm the U.S. economy, jobs and living standards, and that the door remains open for the U.S. to reenter.

Effects on climate science
Carbon Direct says leaving the UNFCCC and IPCC will reduce the financial resources, expertise and data available to the international climate science and policy community, and will result in incomplete global emissions inventories.
The IPCC will keep producing reports. The Union of Concerned Scientists' Delta Merner said walking away leaves people, policymakers and businesses flying in the dark when credible climate information is most needed.
Inside Climate News reported in December 2025 that the global scientific community is planning long-term carbon monitoring with less reliance on NOAA, after the WMO confirmed a record annual rise of 3.5 parts per million in atmospheric carbon dioxide.
Scholars at the American Enterprise Institute, a conservative think tank, argue the U.S. helped create the IPCC in the 1980s and that a robust IPCC serves U.S. interests in economics, defense and science.

What the sources do not establish
Carbon Direct notes a global debate over whether a U.S. president can unilaterally exit these agreements. The sources reviewed do not confirm effective dates for the UNFCCC or IPCC exits.
The sources reviewed do not say which U.S. scientists continue to take part in IPCC reports in a personal capacity.

Perspectives

Official position — White House (Jan. 7, 2026 memorandum)
The memorandum withdraws the U.S. from international organizations, conventions and treaties that the administration says are contrary to the interests of the United States, following a review ordered by Executive Order 14199.

Expert view — UNFCCC Executive Secretary Simon Stiell
Stiell said the step back from global leadership, climate cooperation and science can only harm the U.S. economy, jobs and living standards, and that the door remains open for the U.S. to reenter in the future.

Critic — American Enterprise Institute scholars (conservative think tank)
AEI scholars argue that leaving the IPCC and UNFCCC is bad for the United States, noting the U.S. helped create the IPCC in the 1980s and that a robust IPCC serves U.S. interests in economics, defense and science.

Critic — Union of Concerned Scientists (Delta Merner)
Merner said walking away does not make the science disappear and only leaves people across the United States, policymakers and businesses flying in the dark at the moment when credible climate information is most urgently needed.

Editorial read — The Author (site author)
The Author's view is that the U.S. should stay in the bodies that assess climate science, because other countries continue to take part and U.S. scientists lose influence by leaving. This is interpretation. The sources show the withdrawals and warnings from critics, including a conservative think tank, and the administration's position that the bodies are contrary to U.S. interests; none measures the harm, and effective dates are not confirmed.

Research notes
Open leads: (1) Effective dates and legal status of the UNFCCC and IPCC exits; (2) which U.S. scientists still participate in IPCC reports in a personal capacity; (3) the Carbon Direct analysis is a commercial source and is used for context only; (4) the Oil & Gas Journal summary of supporters' views names only one speaker by surname and is not quoted.

Note
Supporters say the exits restore U.S. sovereignty and advance energy independence. Critics, including scholars at the conservative American Enterprise Institute, say leaving the IPCC and UNFCCC harms U.S. interests. Whether a president can leave these bodies unilaterally is debated, and the sources reviewed do not confirm effective dates for each.

Sources
[1] IISD SDG Knowledge Hub: US withdraws from 65 international organizations, UN agencies (https://sdg.iisd.org/news/us-withdraws-from-65-international-organizations-un-agencies/) · 2026-01
[2] Eos: Trump pulls United States out of international climate treaties "contrary to national interests" (https://eos.org/research-and-developments/trump-pulls-united-states-out-of-international-climate-treaties-contrary-to-national-interests) · 2026-01
[3] Carbon Direct: The United States' unconventional withdrawal from the UNFCCC (https://www.carbon-direct.com/insights/the-united-states%E2%80%99-unconventional-withdrawal-from-the-unfccc) · 2026-01-15
[4] American Enterprise Institute: Leaving the IPCC and UNFCCC is Bad for the United States (https://ctse.aei.org/leaving-the-ipcc-and-unfccc-is-bad-for-the-united-states/) · 2026-01-08
[5] Inside Climate News: Global Scientists Anticipate Less Reliance on the US in Future Carbon Monitoring (https://insideclimatenews.org/news/05122025/global-scientists-carbon-monitoring-noaa-cuts/) · 2025-12-05

Connections

Related — Environmental deregulation under EPA Administrator Lee Zeldin
Both are part of the administration's broader retreat from climate policy and science.

Related — Ocean observing under budget pressure: NOAA research cuts, Argo floats and the end of U.S. biogeochemical Argo (2025-2026)
Both reduce U.S. participation in shared global observation and assessment: Argo funding and NOAA research there, IPCC and UNFCCC participation here.