The United Nations Framework Convention on Climate Change (UNFCCC) is a process led by the United Nations to help countries work together to create an agreement that limits dangerous climate change. This international treaty brings countries together to address "dangerous human interference with the climate system." The main way to do this is by reducing the amount of greenhouse gases in the atmosphere. The Convention established the principle of "common but differentiated responsibilities," which means all countries share the responsibility to address climate change. However, developed countries are expected to take the lead because they have historically emitted more greenhouse gases. The treaty was signed in 1992 by 154 countries at the United Nations Conference on Environment and Development (UNCED), also known as the Earth Summit, held in Rio de Janeiro. The treaty became active on 21 March 1994. "UNFCCC" is also the name of the Secretariat, an organization that supports the work of the Convention, with offices on the UN Campus in Bonn, Germany.

The main goal of the Convention is described in Article 2. It is to "stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous human-caused interference with the climate system." The treaty encourages ongoing scientific research about the climate. This research helps support meetings and negotiations that lead to agreements. The aim is to help ecosystems adapt to climate change, protect food production from its effects, and allow economic development to continue in a sustainable way. The UNFCCC's current focus is on implementing the Paris Agreement, which became active in 2016. This agreement aims to limit the rise in global temperature to well below 2°C (3.6°F) above pre-Industrial Revolution levels, with a goal of keeping it below 1.5°C (2.7°F). The Paris Agreement replaced the Kyoto Protocol, which was signed in 1997 and was in effect from 2005 to 2020.

By 2022, the UNFCCC had 198 participating countries or regions. Its highest decision-making body, the Conference of the Parties (COP), meets every year. Other meetings at the regional and technical levels happen throughout the year. The Paris Agreement requires a review, called a "global stocktake," of progress toward its goals every five years. The first review took place at COP28 in the United Arab Emirates (UAE) in 2023.

The treaty outlines responsibilities for three groups of countries: developed countries, developed countries with special financial responsibilities, and developing countries. Developed countries are referred to as Annex I countries. At first, there were 38 of them. These countries are expected to create national policies and take actions to reduce their greenhouse gas emissions. They must also report on steps to return to their 1990 greenhouse gas emission levels individually or together.

Some key signatory countries are not following their commitments, which has led to criticism that the UNFCCC has not been effective in reducing greenhouse gas emissions since its creation. Parties to the convention have not agreed on a process that allows decisions to be made by majority vote. All decisions must be made by consensus, which means any country can block an agreement. The effectiveness of the Paris Agreement in meeting its climate goals is also being debated, especially regarding its more ambitious goal of keeping global temperature rise below 1.5°C.

A recent study suggests that alternating between in-person meetings and virtual thematic sessions could help improve fairness and effectiveness in climate governance under the UNFCCC framework.

Development

The IPCC's First Assessment Report was published in 1990. It provided a general summary of climate change science and the scientific agreement at that time. The report explained uncertainties and showed evidence of rising global temperatures. The authors stated they were certain that greenhouse gases in the atmosphere are increasing because of human activities. This is causing the Earth's surface to warm more. This report led to the creation of the United Nations Framework Convention on Climate Change (UNFCCC).

The text of the UNFCCC was written during a meeting of an Intergovernmental Negotiating Committee in New York from April 30 to May 9, 1992. The convention was approved on May 9, 1992, and became available for signing on June 4, 1992, at the United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro, also called the Earth Summit. On June 12, 1992, 154 countries signed the UNFCCC. After ratification, these countries agreed to reduce greenhouse gas levels in the atmosphere with the goal of "preventing dangerous human-caused changes to Earth's climate system." This goal would require significant reductions in greenhouse gas emissions (see the later section, "Stabilization of greenhouse gas concentrations"). Since 1995, countries that are part of the UNFCCC have met yearly in Conferences of the Parties (COPs) to review progress on climate change.

Article 3(1) of the UNFCCC says that countries should work to protect the climate system based on "common but differentiated responsibilities and respective capabilities." This means that developed countries should take the lead in addressing climate change. Under Article 4, all countries have general responsibilities to tackle climate change, such as reducing emissions and preparing for the effects of climate change. Article 4(7) states:

The UNFCCC set a goal for countries listed in Annex I to stabilize their greenhouse gas emissions (carbon dioxide and other human-caused gases not covered by the Montreal Protocol) at 1990 levels by the year 2000.

The main goal of the UNFCCC is described in Article 2: "stabilizing greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous human-caused changes to the climate system." Article 2 also says this goal should be reached within a time frame that allows ecosystems to adapt naturally, ensures food production is not threatened, and supports sustainable economic development.

Action for Climate Empowerment (ACE) is a term introduced by the UNFCCC in 2015 to replace the name "Article 6." It refers to Article 6 of the original UNFCCC text (1992), which focuses on six key areas: education, training, public awareness, public participation, access to information, and international cooperation on these issues. Addressing all six areas is seen as essential for helping people understand and take part in solving climate change challenges. ACE encourages governments to create educational programs, train workers in science and management, improve access to information, and involve the public in climate change efforts. It also asks countries to work together by sharing successful practices and strengthening national institutions. These activities are guided by specific goals that are important for carrying out climate adaptation and mitigation efforts and achieving the UNFCCC's main goal.

Key agreements and protocols

The Kyoto Protocol was an international agreement that added rules to the 1992 United Nations Framework Convention on Climate Change (UNFCCC). It required countries to reduce greenhouse gas emissions because scientists believe human-caused carbon dioxide emissions are causing global warming. The Kyoto Protocol was created in Kyoto, Japan, on December 11, 1997, and became active on February 16, 2005. In 2020, 192 countries were part of the agreement, though Canada left in 2012.

The Kyoto Protocol aimed to lower greenhouse gas levels in the atmosphere to prevent dangerous changes to Earth’s climate. It focused on seven gases: carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF₆), and nitrogen trifluoride (NF₃). Nitrogen trifluoride was added later during the Doha Round.

The agreement was based on the idea that developed countries, which historically contributed more to climate change, should take the lead in reducing emissions because they have more resources. The first period of the Kyoto Protocol ran from 2008 to 2012. All 36 countries fully involved met their goals, but nine needed to fund emission reductions in other countries to meet their targets. The 2008 financial crisis helped lower emissions, and former Eastern Bloc countries saw large drops because of changes after the Soviet Union ended. Despite efforts by 36 developed countries, global emissions rose by 32% between 1990 and 2010.

The Paris Agreement, signed in 2016, is another international treaty about climate change. It covers reducing emissions, adapting to climate impacts, and providing financial support. The agreement was created by 196 countries during a 2015 meeting in Paris, France. As of January 2026, 194 UNFCCC members were part of the agreement, though Iran, the United States (which left in 2020 and rejoined in 2021), and one other country had not fully joined.

The Paris Agreement aims to keep global temperatures from rising more than 2°C (3.6°F) above pre-industrial levels, with a goal of limiting the increase to 1.5°C (2.7°F). These goals are based on average temperature measurements over many years.

Other agreements, like the Bali Action Plan (2007), Copenhagen Accord (2009), Cancún agreements (2010), and Durban Platform (2012), were also created during UNFCCC meetings. The Bali Action Plan required developed countries to set measurable emission reduction targets, while developing countries agreed to take steps to reduce emissions with help from technology, funding, and training.

The Copenhagen Accord, agreed to by 114 countries, aimed to limit global warming to below 2°C (3.6°F). However, the agreement was not officially adopted by the UNFCCC. The Cancún agreements required both developed and developing countries to submit plans to reduce emissions.

In 2021, the UNFCCC launched the "UN Race-to-Zero Emissions Breakthroughs" campaign. Its goal is to transform 20 economic sectors to reach zero greenhouse gas emissions. At least 20% of each sector must take action, and 10 sectors should be changed before the 2026 UN Climate Change Conference in Glasgow. Organizers say 20% is a key point for lasting change.

The Durban Platform and other agreements reminded the UN of the needs of developing countries. UN Sustainable Development Goal 13 (SDG 13) includes a target to help developing countries with climate action. It aims to raise $100 billion annually by 2020 to support these efforts through the Green Climate Fund.

The Green Climate Fund (GCF) was created under the UNFCCC to help developing countries with climate change. It is the largest fund of its kind and focuses on projects that reduce emissions or help countries adapt to climate impacts. The GCF is based in Incheon, South Korea, and is managed by a 24-member board. Mafalda Duarte, a Portuguese economist, is the fund’s leader.

The GCF supports projects in developing countries through specific funding programs. It is meant to be the main way the UN raises money for climate action. Other smaller climate funds also exist.

Secretariat and offices

"UNFCCC" is also the name of the Secretariat, which is responsible for helping with the work of the convention. Its offices are located on the UN Campus in Bonn, Germany. Previously, offices were in Haus Carstanjen and a building on the UN Campus called Langer Eugen.

The Secretariat was created under Article 8 of the convention and is led by the Executive Secretary. With help from the Intergovernmental Panel on Climate Change (IPCC), the Secretariat works to help countries agree through meetings and discussions about strategies to address climate change. Since the UNFCCC treaty was signed, Conferences of the Parties (COPs) have met to discuss how to achieve the treaty's goals.

From 2010 to 2016, Christiana Figueres was the head of the Secretariat. She was followed by Patricia Espinosa, who became Executive Secretary on May 18, 2016, after being appointed by United Nations Secretary-General Ban Ki-moon. Espinosa started her role on July 18, 2016, and left her position on July 16, 2022. During this time, UN Under Secretary General Ibrahim Thiaw acted as the Executive Secretary. On August 15, 2022, Secretary-General António Guterres named Simon Stiell, a former Grenadian climate minister, as the new Executive Secretary, replacing Espinosa.

Current and former Executive Secretaries include:

Processes

The reports from the IPCC are very important for the yearly climate talks held by the UNFCCC. For example, the UNFCCC asked the IPCC to prepare a report about global warming of 1.5 °C. The IPCC then released the Special Report on Global Warming of 1.5 °C (SR15) in 2018. The report showed that it is possible to keep warming below 1.5 °C during the 21st century. However, this would require large reductions in emissions and major changes in society. The report also said that warming of 2 °C would cause much worse effects than 1.5 °C. In other words, even small increases in temperature matter a lot. SR15 had an unusual effect on the media and the public. It made the 1.5 °C goal a central focus for climate activism.

The United Nations Climate Change Conferences are yearly meetings held under the UNFCCC. These meetings are where the UNFCCC Parties (called Conferences of the Parties or COP) gather to check progress on climate change. Starting in the mid-1990s, these meetings also discussed the Kyoto Protocol, which created legally binding rules for developed countries to reduce greenhouse gas emissions. Since 2005, these conferences also serve as the Meetings of Parties for the Kyoto Protocol (CMP). Since 2016, they also serve as the Meetings of Parties for the Paris Agreement (CMA).

The first conference (COP1) was held in 1995 in Berlin. The third conference (COP3) took place in Kyoto and led to the Kyoto Protocol, which was updated during the 2012 Doha Conference (COP18, CMP8). The COP21 (CMP11) conference was in Paris in 2015 and resulted in the Paris Agreement. COP28 happened in the United Arab Emirates in 2023 and included the first global review under the Paris Agreement. The UAE chose Sultan al-Jaber, who also leads Abu Dhabi’s national oil company ADNOC, to lead COP28. Azerbaijan will host COP29 in 2024.

A subsidiary body is a committee that helps the Conference of the Parties. Subsidiary bodies include:

• Permanent: The Subsidiary Body for Scientific and Technological Advice (SBSTA) was created by the convention to give the COP and other groups timely scientific and technical information. It connects information from experts, like the IPCC, with the COP, which focuses on making policies. The Subsidiary Body for Implementation (SBI) was created by the convention to help the COP review how well the convention is being followed. It gives policy and implementation advice to the COP and other groups if needed.

• Temporary: Ad hoc Group on Article 13 (AG13), active from 1995 to 1998; Ad hoc Group on the Berlin Mandate (AGBM), active from 1995 to 1997; Ad Hoc Working Group on Further Commitments for Annex I Parties under the Kyoto Protocol (AWG-KP), created in 2005 to discuss future emission reductions for industrialized countries under the Kyoto Protocol. This group finished its work in 2012 when the CMP approved the Doha Amendment. Ad Hoc Working Group on Long-term Cooperative Action (AWG-LCA), created in Bali in 2007 to negotiate a stronger international climate deal. Ad Hoc Working Group on the Durban Platform for Enhanced Action (ADP), created at COP17 in Durban in 2011 to develop a new agreement, legal instrument, or outcome with legal force for all countries. The ADP completed its work in Paris on December 5, 2015.

A "National Communication" is a report that countries that have joined the UNFCCC must submit. Developed countries must send these reports every four years, and developing countries should do so as well. Some Least Developed Countries have not sent reports in the past 5–15 years, mainly because they lack the resources to do so.

National Communication reports are often hundreds of pages long and describe a country’s efforts to reduce greenhouse gas emissions and how climate change affects the country. These reports follow guidelines agreed upon by the COP. The (Intended) Nationally Determined Contributions (NDCs), which are the basis of the Paris Agreement, are shorter and less detailed but also follow a standard format and are reviewed by experts.

At the 19th meeting of the COP in Warsaw in 2013, the UNFCCC created a way for countries to submit Intended Nationally Determined Contributions (INDCs) before the 21st COP meeting in Paris (COP21) in 2015. Countries were allowed to create plans that fit their own needs. This flexibility let developing countries design plans that match their specific climate goals and other needs.

After COP21, these INDCs became Nationally Determined Contributions (NDCs) once each country joined the Paris Agreement, unless a new NDC was submitted to the UNFCCC at the same time. The 22nd COP meeting (COP22) in Marrakesh focused on these NDCs and how to carry them out after the Paris Agreement started on November 4, 2016.

Membership and participation

As of 2022, the UNFCCC has 198 members, including all United Nations member states, United Nations General Assembly observers such as the State of Palestine and the Holy See, UN non-member states like Niue and the Cook Islands, and the supranational union, the European Union.

The United States announced its plan to leave the treaty in January 2026. This is the only country to make such a decision.

Members of the UNFCCC are grouped into categories:

• Annex I: There are 43 members listed in Annex I, including the European Union. These members are classified as developed countries or "economies in transition" (EITs). The 14 EITs include former centrally-planned economies from Russia and Eastern Europe.
• Annex II: Of the 43 Annex I members, 24 are also listed in Annex II, including the European Union. These members are part of the Organisation for Economic Co-operation and Development (OECD) as they existed in 1992, with Turkey excluded and the European Union added. Annex II members must help EITs and developing countries reduce greenhouse gas emissions and manage climate change impacts.
• Least-developed countries (LDCs): There are 49 LDCs. These countries receive special support under the treaty because they have limited ability to adapt to climate change effects.
• Non-Annex I: Members not in Annex I are mostly low-income developing countries. Some developing countries may join Annex I if they become sufficiently developed.

There are 43 Annex I members, including the European Union. These are developed countries or EITs. Of these, 24 are also Annex II members, and 14 are EITs.

Annex I members (24 of these are also Annex II members):
Annex I members that are EITs:

In 2014, the United Nations, along with Peru and France, created the Global Climate Action Portal, NAZCA, to track and review climate commitments.

Thousands of observers from civil society, businesses, and universities attend the COP meetings. They organize many activities, including official "side events" that support the main negotiations.

Civil society observers under the UNFCCC have formed informal groups that include about 90% of all registered organizations. Some groups, such as faith-based organizations or national parliamentarians, are not part of these larger groups. The UNFCCC secretariat also recognizes these informal groups as of 2016: Faith-based organizations, Education and Capacity Building and Outreach NGOs, and parliamentarians.

An overview is given in the table below.

Analysis

The main goal of the Framework Convention includes important terms explained below and shown in italics: "stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous human-caused interference with the climate system."

To keep greenhouse gas levels stable in the atmosphere, worldwide human-caused greenhouse gas emissions must first reach a peak and then decrease (see climate change mitigation). Lower target levels for stabilization would require emissions to peak and decrease earlier than for higher target levels. These lower target levels are linked to smaller amounts of global warming compared to higher target levels.

People have different opinions about what level of climate change is dangerous. Scientific studies can explain the risks of climate change, but deciding which risks are dangerous depends on personal values and choices.

The global warming that has already happened poses risks to some human and natural systems. Larger amounts of global warming usually increase the risk of harmful effects. Climate change risks are "considerable" with 1 to 2 °C of global warming compared to before the industrial era. A 4 °C increase in warming would lead to much greater risks, including widespread loss of plant and animal life and less food availability worldwide and in specific regions.

Climate change policies might create costs that are important to Article 2. For example, stricter policies to control greenhouse gas emissions could reduce the risk of more severe climate change, but these policies might also cost more to carry out.

When making decisions, the precautionary principle is used when events that could be dangerous, irreversible, or catastrophic are possible, but scientific evidence about the possible harm is not certain. This principle suggests a focus on preventing harmful effects. Following this principle, uncertainty about the exact effects of climate change is not a reason to take no action. This idea is recognized in Article 3.3 of the UNFCCC.

Some experts and environmental groups criticize Article 3(5) of the convention, which says that climate measures that could limit international trade should be avoided.

Reception

The United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol, which were created to reduce greenhouse gas emissions, have faced criticism for not meeting their goals. The UNFCCC is an international organization focused on climate change, but it can be slow to make decisions because it includes over 190 countries and requires agreement from all members. This can lead to delays or failures in creating effective policies.

Since 1992, international agreements to reduce emissions have not been successful. Some countries, like the United States, did not agree to the Kyoto Protocol because it did not require developing countries to reduce emissions, even though many of these countries now produce large amounts of carbon dioxide. The Kyoto Protocol also did not consider the responsibility of developed countries for past emissions or the emissions linked to goods imported from other countries. Canada left the Kyoto Protocol in 2011 because it did not want to pay penalties that would cost its citizens money. Both the United States and Canada now use voluntary programs to reduce emissions instead of following the Kyoto Protocol.

Some countries believe the Kyoto Protocol has not worked well, so they are focusing on other efforts, such as the Climate and Clean Air Coalition. This group aims to reduce short-lived pollutants like methane and black carbon, which contribute to global warming but are easier to regulate than long-term emissions.

In 2010, Japan said it would not join a second phase of the Kyoto Protocol because it would face restrictions that its competitors, such as China and India, would not. New Zealand’s leader also expressed similar concerns in 2012. At a 2012 meeting, some countries objected to parts of the Kyoto Protocol, but their concerns were ignored. These actions have made the UNFCCC process more difficult and costly, as seen in the United Kingdom, where climate-related travel expenses reached over £1,300,000 in two years.

The Kyoto Protocol also failed to help developing countries access technologies that reduce the harm of climate change, such as renewable energy. The UNFCCC created a group called the "technology mechanism" to share these resources, but it did not provide enough support. This led to low participation in the second phase of the Kyoto Protocol, which was not completed.

The Paris Agreement, created in 2015, is being debated for its ability to meet climate goals, especially the target of limiting global warming to 1.5°C. Many experts believe the current commitments under the Paris Agreement are not enough to reach this goal. The agreement’s rules are still being worked out, so it is too early to fully assess its success. A 2020 report by the United Nations Environment Programme said that if current plans are followed, global temperatures could rise by more than 3°C by the end of the 21st century. Some countries have made new promises to reach net zero emissions, which could reduce warming by about 0.5°C.

Current pledges by countries are not enough to meet climate goals, so stronger and more costly actions will be needed in the future. There is also a gap between what countries promise and what they actually do. Studies show that as of 2017, major industrialized nations had not implemented the policies they promised, and even if they had, their combined efforts would not keep warming below 2°C.

A 2021 study found that emissions must be reduced 80% more than current plans to meet the 2°C target. The chances of major emitters meeting their goals without this increase are very low. If current trends continue, the chance of keeping warming below 2°C is between 5% and 26%.

As of 2020, there is limited research on how well the Paris Agreement is helping countries adapt to climate change or build their capacity to address it. The available studies are mixed in their conclusions about loss and damage from climate change.

A recent report showed that the Paris Agreement has had an impact: in 2010, scientists predicted a temperature rise of 3.7–4.8°C by 2100, but by 2023, this range had narrowed to 2.4–2.6°C. If all countries meet their long-term goals, warming could be limited to 1.7–2.1°C. However, the world is still far from the goal of limiting warming to 1.5°C. To do this, emissions must peak by 2025. Recent data shows that 2024 was the first full year with an average temperature above 1.5°C, suggesting that the world may have already entered a period of 20 years with an average warming of 1.5°C. Some scientists believe the 1.5°C threshold may have already been crossed in 2024.

The Paris Agreement has also influenced the focus of the Intergovernmental Panel on Climate Change (IPCC). Before the agreement, IPCC reports discussed temperatures above and below 2°C equally. However, after the Paris Agreement, the 6th IPCC report focused more on temperatures below 2°C, with nearly 50% of mentions about 1.5°C and less than 20% about temperatures above 2°C.

Awards

In 2016, the UNFCCC was awarded the "Prince or Princess of Asturias Award for International Cooperation" by the Princess of Asturias Awards.