How will the U.S. exit affect climate action?

0.1 Context: Why this news is important

0.1.1 U.S. President Donald Trump has signed a presidential memorandum withdrawing the U.S. from 66 international organisations.
0.1.2 These include key climate bodies such as the UN Framework Convention on Climate Change (UNFCCC) and the Intergovernmental Panel on Climate Change (IPCC).
0.1.3 The decision raises concerns about its impact on global climate diplomacy, climate finance, and international cooperation.

What does the U.S. exiting the UNFCCC mean?

1.1 Background to the decision

1.1.1 Donald Trump has repeatedly described climate change as a hoax.
1.1.2 The U.S. government is already in the process of withdrawing from the Paris Agreement.
1.1.3 On February 4, 2025, an executive order was issued directing the government to review which organisations and treaties the U.S. is party to and whether they are contrary to U.S. interests.
1.1.4 The decision to exit the UNFCCC and IPCC followed this review.

1.2 Consequences of exiting the UNFCCC

1.2.1 Exiting the UNFCCC will exclude the U.S. from the core framework that organises almost all multilateral climate diplomacy.
1.2.2 The U.S. will no longer participate in:

• 1.2.2.1 The UNFCCC reporting system that tracks countries’ greenhouse gas emissions and progress on commitments
• 1.2.2.2 Collective monitoring and accountability mechanisms among nations

1.3 Impact on participation in climate negotiations

1.3.1 Withdrawing from the UNFCCC is treated as withdrawing from all protocols under it, including the Paris Agreement.
1.3.2 The U.S. will cease to be a party to the system that runs:

• 1.3.2.1 Annual Conference of Parties (COP) negotiations
• 1.3.2.2 Rule-making processes on transparency, carbon markets, and climate finance

1.3.3 The U.S. may still attend COP meetings as an observer, but:

• 1.3.3.1 It will not have legal standing
• 1.3.3.2 It will not have bargaining power as a negotiating party

How will climate finance be affected?

2.1 Financial mechanisms under the UNFCCC

2.1.1 The UNFCCC has a financial mechanism with operating entities such as:

• 2.1.1.1 The Global Environment Facility
• 2.1.1.2 The Green Climate Fund
  2.1.2 The COP oversees how this financial architecture functions.

2.2 Implications of U.S. exit

2.2.1 If the U.S. is no longer a party, it will lose influence over how climate finance rules evolve.
2.2.2 Exit also makes it politically easier for a U.S. administration to withhold financial contributions.
2.2.3 At the same time, withdrawal increases the “cost of doing climate business” for U.S. companies.

2.3 Impact on private sector and economic interests

2.3.1 Many U.S. companies, investors, insurers, and subnational governments plan investments assuming:

• 2.3.1.1 Global climate rules will become tighter over time
  2.3.2 The U.S. exit signals policy volatility, which may:
• 2.3.2.1 Increase risk premiums
• 2.3.2.2 Expose U.S. exporters to foreign climate-related trade measures

2.4 Broader diplomatic implications

2.4.1 Climate cooperation is increasingly linked with negotiations on:

• 2.4.1.1 Energy security
• 2.4.1.2 Critical minerals
• 2.4.1.3 Industrial policy
• 2.4.1.4 Development finance

2.4.2 Countries may become less willing to strike deals with the U.S. in adjacent domains due to doubts about the durability of U.S. commitments.

What does the IPCC do?

3.1 Role of the IPCC

3.1.1 The IPCC assesses scientific research on climate change.
3.1.2 It compiles reports that synthesise:

• 3.1.2.1 The current understanding of climate science
• 3.1.2.2 The impacts of climate change
• 3.1.2.3 Potential mitigation and adaptation strategies

3.1.3 Policymakers worldwide rely on IPCC reports to design climate policies.

3.2 Effect of U.S. withdrawal from the IPCC

3.2.1 Pulling out of the IPCC would weaken the U.S.’s role in shaping the shared scientific references used in climate negotiations.
3.2.2 It does not mean U.S. scientists will stop working on climate research, but:

• 3.2.2.1 Overall U.S. involvement is likely to reduce
• 3.2.2.2 The pipeline of U.S.-based expertise may narrow

3.2.3 IPCC authors are nominated by governments and observer organisations, and teams are formed by the IPCC Bureau.
3.2.4 If the U.S. stops nominating experts:

• 3.2.4.1 U.S.-based expertise in IPCC reports could decline

3.3 Continued but limited participation

3.3.1 The IPCC allows experts who are nominated but not selected to contribute as expert reviewers.
3.3.2 U.S. researchers could also participate through non-government routes, such as observer organisations.

What are the global repercussions?

4.1 Impact on reciprocity and trust

4.1.1 Climate negotiations rely heavily on reciprocity.
4.1.2 When a very wealthy, high-emissions country exits, it weakens expectations that:

• 4.1.2.1 Other major emitters will follow shared rules

4.2 Effect on developing countries

4.2.1 Many poorer countries already believe that rich countries:

• 4.2.1.1 Promise more than they deliver
  4.2.2 The U.S. exit may:
• 4.2.2.1 Harden scepticism
• 4.2.2.2 Provide cover for reluctant governments to delay or dilute action

4.3 Climate finance gap

4.3.1 Climate finance discussions have shifted from:

• 4.3.1.1 The older $100 billion goal
• 4.3.1.2 To much larger needs and targets

4.3.2 According to the OECD, developed countries mobilised $115.9 billion in 2022, the first time exceeding $100 billion.
4.3.3 However:

• 4.3.3.1 Adaptation finance remains far below needs
• 4.3.3.2 The UN Adaptation Gap Report estimates $310–365 billion per year by 2035
• 4.3.3.3 International public adaptation finance was only about $26 billion in 2023

4.4 Implications for future climate targets

4.4.1 At COP29 in 2024, governments agreed to pursue a new collective quantified goal of at least $300 billion per year by 2035.
4.4.2 The U.S. exiting key climate bodies makes it harder to:

• 4.4.2.1 Reach consensus on such targets
• 4.4.2.2 Persuade other countries to pay more when a major historical emitter steps away

4.5 Overall impact on global climate action

4.5.1 The U.S. exit weakens:

• 4.5.1.1 Multilateral climate governance
• 4.5.1.2 Scientific coordination
• 4.5.1.3 Trust in long-term climate cooperation