Climate Diplomacy

Overview

Climate diplomacy refers to international dialogues and negotiations that specifically relate to global climate change. Environmental diplomacy is a broader term that covers issues ranging from biodiversity and natural resources to chemicals and pollution. The United Nations (UN) Conference on the Human Environment, often referred to as the Stockholm Conference, laid the foundation for international cooperation on global environmental challenges in 1972.

A prominent example of climate diplomacy in action is the UN Framework Convention on Climate Change (UNFCCC). The UNFCCC brings together almost every country across the globe, through major summits and other events, to discuss and negotiate international climate policies on issue including greenhouse gas emissions, climate adaptation, and international climate finance. In 2015, countries agreed to the landmark Paris Agreement under the UNFCCC, which established the international goal to “limit global temperature increase to well below 2°C [3.6°F], while pursuing efforts to limit the increase to 1.5°C [2.7°F].” The Paris Agreement continues to provides the structure under which countries cooperate today.

The United States ratified the UNFCCC in 1992, and joined the Paris Agreement in 2016 via executive agreement. The first Trump Administration subsequently left the Paris Agreement in 2020. The United States rejoined the agreement in 2021, but the second Trump Administration left it again in 2026.

Also in January 2026, the United States announced its intent to leave more than 60 international organizations, including the UNFCCC. This departure takes effect one year after the withdrawal is formally registered with the convention. The United States plans to leave other programs and organizations relevant to environmental diplomacy, including the Intergovernmental Panel on Climate Change, UN Energy, UN Oceans, the International Renewable Energy Agency, and the International Union for the Conservation of Nature. Each entity has its own process for withdrawal and many take time to enter into effect.   

Climate change is a global issue. Rising sea levels, the introduction of diseases to new regions, and increased risk of extreme weather transcend borders and threaten the lives of people across nations. Both the UN General Assembly and UN Security Council have stated that climate change is a threat to international peace and security.

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Read More: Climate Change | National Security and Energy Independence

International Climate Science

The impetus for international cooperation on climate change comes from the scientific understanding that human activities, namely burning fossil fuels, are rapidly warming the Earth. The World Meteorological Organization (WMO), a UN agency, has provided scientific information on the climate to countries since it was established in 1950 as the successor to the International Meteorological Organization. In 1979, the WMO held the First World Climate Conference, which led to the creation of the WMO World Climate Programme. Today, the WMO continues to study the climate system and provide climate services that give users the tools to interpret this information and apply it to decision-making.

Together with the UN Environment Programme, WMO established the Intergovernmental Panel on Climate Change (IPCC) in 1988. The IPCC is the authoritative body compiling research on climate change to inform country decisions and international negotiations. As of 2025, the IPCC has conducted six synthesis reports and numerous special reports on issues such as global warming of 1.5°C, climate change and land, and the ocean and cryosphere. Scientists from around the world contribute to these reports as authors and reviewers, and country representatives also play a role in informing the reports, especially the content of the summary for policymakers, which accompanies each IPCC output.

International Cooperation

Climate diplomacy operates through multilateral diplomacy (negotiation among three or more countries) and bilateral diplomacy (negotiation between two countries). Meetings between countries range from regional conferences to global summits. The outcomes can include treaties, treaty amendments, partnerships, and memorandums of understanding. Subnational entities, including states, cities, tribes, and businesses, are often responsible for operationalizing climate and environmental agreements, so they also engage in discussions at the international level to inform policy development.

The Montreal Protocol, which is focused on addressing ozone pollution, is generally considered as one of the most effective multilateral environmental agreements to date. Countries committed to phase down use of 100 ozone depleting substances in 1987, and today 98% of these substances have been eliminated from production and use. The ozone layer is on track to recover by about 2050. As research continued over this time period, scientists realized that a main substitute for ozone depleting substances is a potent greenhouse gas, so countries established the Kigali Amendment to the Montreal Protocol to also reduce the use of these hydrofluorocarbons. 

The Paris Agreement, under the UNFCCC, is one of the most significant accomplishments in multilateral climate diplomacy. The Paris Agreement entered into force in November 2016 less than one year after it was adopted at the 21^st Conference of the Parties to the UNFCCC (COP21) in 2015. The Paris Rulebook lays out the guidelines for how countries will implement the Paris Agreement, which initiated a new era of climate diplomacy centered on implementation and accountability. As part of the agreement, each participating country regularly submits commitments to reduce its greenhouse gas emissions, known as its nationally determined contribution. Countries agree to carry out and report on their progress towards their commitments to meet the overall goal of the Paris Agreement to keep global temperature rise below 2°C [3.6°F] and ideally below 1.5°C [2.7°F].

U.S. Engagement in Multilateral Climate and Environment Diplomacy

The United States has ratified many multilateral environmental treaties and has engaged in numerous international organizations and forums to advance work on climate, energy, and environmental issues. The following list of treaties that the U.S. government has ratified, as of January 2025, highlights examples of U.S. engagement in this space, but it is not an exhaustive list. The Department of State maintains a full list of Treaties in Force, which includes both multilateral and bilateral agreements with categories for “environment & conservation” and “energy.”

Multilateral Agreements without U.S. Participation

The United States has not ratified a number of significant international treaties on environmental issues, including those outlined in the table below.

U.S. Engagement in Bilateral Climate and Environment Diplomacy

The United States has historically worked bilaterally with many countries on environmental and climate issues. Globally significant bilateral climate efforts include those with India and China. In 2021, the United States entered a bilateral agreement with the government of India. The U.S.-India Climate and Clean Energy Agenda 2030 Partnership primarily focused on increasing climate finance and clean energy deployment.

The United States and China are the two largest emitters of greenhouse gas emissions. In 2014, then President Barack Obama and President Xi Jinping of China issued a joint announcement to reduce carbon dioxide emissions, conduct research together on clean energy, and address hydrofluorocarbon climate super pollutants. This was the first time China publicly committed to peaking its carbon dioxide emissions by a specific date (around 2030). This bilateral cooperation set the groundwork for the Paris Agreement to be adopted the following year. In 2021, the United States and China made the U.S.-China Joint Glasgow Declaration on Enhancing Climate Action in the 2020s, which committed the two countries to cooperating on a variety of climate issues. This effort continued in 2023 with the U.S.-China Sunnylands Statement on Enhancing Cooperation to Address the Climate Crisis.

Federal Agencies Involved in Global Environmental Issues

Responsibility for climate diplomacy weaves across several federal agencies. The following section describes the ways agencies have been involved in global environmental projects, negotiations, and summits.

Department of Agriculture

The U.S. Department of Agriculture (USDA) houses the Foreign Agricultural Service, which has offices in about 100 countries and is focused on U.S. agricultural exports and food security.

Department of Defense

Climate change impacts, including flooding and extreme heat, negatively affect U.S. military installations. Climate change is also considered to be a threat multiplier—a factor that makes security issues around the world worse. The 2008 National Defense Authorization Act (NDAA) requires that the Department of Defense’s high-level military strategies consider climate change. Since that time and as of 2025, the NDAA has increasingly included programs and funding to address climate impacts. The Army, Navy, and Air Force have all written climate strategies or plans, which include international partnerships to address shared climate and security concerns.

Department of the Interior

The Department of the Interior’s (DOI’s) Office of International Affairs works internationally to manage natural resources, water, and energy while recognizing cultural heritage and advancing scientific research. DOI’s Technical Assistance Division manages the International Technical Assistance Program, which provides support to international partners on issues like wildlife trafficking, water management, and natural disaster preparedness and response.

Department of State

The Department of State is the lead agency on international diplomacy. The Bureau of Oceans and International Environmental and Scientific Affairs houses most of the offices that cover international environment and climate initiatives. Until 2025, the Office of Global Change was responsible for representing the United States in UNFCCC negotiations and other international climate summits as well as implementing and managing international policy on climate change, but the office was shuttered. The Office of Ocean and Polar Affairs is responsible for policy on international issues related to the ocean, the Arctic, and the Antarctic, which are heavily impacted by climate change.

Environmental Protection Agency

The Environmental Protection Agency’s (EPA’s) Office of International Affairs specializes in global environmental policy related to air pollution, climate adaptation, waste issues, and pollutants like lead and mercury. The EPA also leads the domestic implementation of many international environmental agreements.

U.S. Agency for International Development

The U.S. Agency for International Development (USAID), which was shuttered in July 2025, ran programs around the world to alleviate poverty and advance development. USAID’s 2022-2030 Climate Strategy set six main strategies to address climate change focused on mitigation, conserving and managing ecosystems, adaptation, climate finance, aligning development and climate portfolios, and supporting the most vulnerable communities. USAID had a key role in supporting developing countries to implement both climate mitigation and adaptation projects. The State Department has taken on some of USAID’s operations since its closure.

Learn more about Climate Diplomacy:

• EESI Resources for UN Climate Summits
• Intergovernmental Panel on Climate Change (IPCC)
• United Nations Framework Convention on Climate Change (UNFCCC)
• Earth Negotiations Bulletin Record of Environmental Negotiations
• World Resources Institute UN Climate Change Conference Resource Hub

Other EESI Climate Diplomacy resources:

• Climate Diplomacy
• EESI Condemns U.S. Withdrawal from UN Framework Convention on Climate Change
• 10.5 COP30 Reflections from the Experts
• Rapid Readout: What Congress Needs to Know About COP30: Outcomes and What’s Next
• International Trade and Climate Policy
• COP30 Announcement Tracker: Key Announcements from the 2025 UN Climate Summit
• Keeping it Cool: International Efforts to Reduce Emissions from Refrigerants
• What’s on the Table for the Negotiations
• Energy Efficiency Financing and Cooling Program in Ghana Inspires Neighbors
• Looking to COP30, Here’s Where Key Past COP Announcements Stand

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