The Kyoto Protocol (Japanese: 京都議定書, Hepburn: Kyōto Giteisho) was an international agreement that expanded the 1992 United Nations Framework Convention on Climate Change (UNFCCC). It required countries to reduce greenhouse gas emissions, based on the scientific understanding that global warming is happening and that human-produced carbon dioxide (CO₂) is a major cause. 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 December 2012.

The Kyoto Protocol aimed to lower greenhouse gas levels in the atmosphere to prevent dangerous human-caused harm to the climate. It focused on seven gases listed in Annex A: carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF₆), and nitrogen trifluoride (NF₃). Nitrogen trifluoride was added during the second compliance period in the Doha Round.

The agreement followed the principle that countries have different abilities to address climate change due to economic differences. It required developed nations to reduce emissions first because they historically contributed more greenhouse gases to the atmosphere.

The first commitment period of the Kyoto Protocol lasted from 2008 to 2012. All 36 countries fully participating met their targets, though nine used flexibility mechanisms, such as funding emission reductions in other countries, to meet their goals. The 2008 financial crisis also helped reduce emissions. Former Eastern Bloc countries saw the largest reductions due to the collapse of the Soviet Union in the 1990s. Despite efforts by 36 developed nations, global emissions rose by 32% from 1990 to 2010.

A second commitment period was agreed to in 2012, called the Doha Amendment, extending the Kyoto Protocol until 2020. This period included 37 countries with binding targets, such as Australia, the European Union, Belarus, Iceland, Kazakhstan, Liechtenstein, Norway, Switzerland, and Ukraine. Belarus, Kazakhstan, and Ukraine considered leaving the agreement or not enforcing the amendment. Japan, New Zealand, and Russia participated in the first period but did not set new targets for the second. Canada left the protocol in 2012, and the United States never joined. Canadian leaders said leaving the agreement would avoid a $14 billion fine, which would harm their economy. By October 2020, 147 countries had accepted the Doha Amendment, which became active on December 31, 2020. However, the second commitment period ended on the same day. Of the 37 countries with binding goals, 34 had approved the amendment.

After the Kyoto Protocol’s second commitment period ended in 2020, UNFCCC Climate Change Conferences discussed future actions. This led to the 2015 Paris Agreement, a separate agreement under the UNFCCC, not an amendment to the Kyoto Protocol.

Chronology

In 1992, the United Nations held a conference in Rio de Janeiro about the environment and development. This meeting led to the creation of the Framework Convention on Climate Change (UNFCCC) and other agreements.

In 1995, countries involved in the UNFCCC met in Berlin for the first Conference of Parties (COP) to discuss specific goals for reducing emissions.

In 1997, during December, countries completed the Kyoto Protocol in Kyoto, Japan. This agreement outlined general goals for limiting emissions.

In 2004, Russia and Canada approved the Kyoto Protocol. This made the treaty officially active on February 16, 2005.

In 2011, Canada became the first country to announce it would leave the Kyoto Protocol.

In 2012, the first commitment period under the Kyoto Protocol ended on December 31.

The annual meeting of all countries involved in the Kyoto Protocol is called the Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change (UNFCCC). The first COP meeting took place in 1995 in Berlin (COP 1). The first Meeting of Parties (CMP) under the Kyoto Protocol happened in 2005 alongside COP 11.

Objectives

The main goal of the Kyoto Protocol was to reduce human-caused greenhouse gas (GHG) emissions in a way that considers differences between countries in terms of emissions, wealth, and ability to make reductions. The treaty follows the main ideas from the 1992 UN Framework Convention on Climate Change. According to the treaty, countries listed in Annex I that agreed to the Kyoto Protocol had to meet their GHG emission limits by 2012, as part of the first commitment period (2008–2012). These emission limits are detailed in Annex B of the Protocol.

The Kyoto Protocol's first commitment period was the first detailed step under the UN Framework Convention on Climate Change. The Protocol created a system of ongoing emission reduction periods. It set a schedule starting in 2006 for discussions about emission limits for a second commitment period. The first commitment period ended on December 31, 2012.

The emission limits from the first Kyoto commitment period were not enough to keep GHG levels in the atmosphere from rising. To stabilize GHG concentrations, more reductions will be needed after the first commitment period ended in 2012.

The main goal of the UN Framework Convention on Climate Change (UNFCCC) is to "stabilize greenhouse gas concentrations in the atmosphere at a level that prevents dangerous human-caused changes to the climate system." Even if Annex I countries met their first-round commitments, much larger reductions will be needed in the future to stabilize GHG levels.

For each type of human-caused GHG, different amounts of emission reductions would be needed to meet the goal of stabilizing GHG levels. Carbon dioxide (CO₂) is the most important human-caused GHG. Stabilizing CO₂ levels in the atmosphere would eventually require completely stopping human-caused CO₂ emissions.

To achieve stabilization, global GHG emissions must first reach a peak and then decrease. The lower the target stabilization level, the sooner the peak and decline must happen. For a specific target level, larger reductions now allow for smaller reductions later. However, smaller reductions now would require larger reductions later to reach the same target.

The first Kyoto commitment period can be seen as the first step toward stabilizing GHG levels in the atmosphere. In this way, the first Kyoto commitments may influence what future GHG stabilization level can be achieved.

Principal concepts

The Kyoto Protocol includes several important ideas:

• Binding Commitments for Annex I Parties: The Kyoto Protocol requires countries that agreed to reduce emissions (Annex I Parties) to legally reduce greenhouse gas emissions. These requirements came from the Berlin Mandate, which was part of earlier UNFCCC negotiations.

• Implementation: To meet the Kyoto goals, Annex I Parties must create policies and measures to reduce emissions in their countries. They must also increase the absorption of greenhouse gases and use tools like joint implementation, the clean development mechanism, and emissions trading to earn credits that allow them to emit more greenhouse gases domestically.

• Support for Developing Countries: A fund was created to help developing countries adapt to the effects of climate change.

• Accounting, Reporting, and Review: These steps ensure the Kyoto Protocol is followed correctly.

• Compliance: A Compliance Committee was established to ensure countries follow their commitments under the Protocol.

The Kyoto Protocol outlines three "Flexibility Mechanisms" that help Annex I Parties meet their emission reduction goals. These are:
1. International Emissions Trading (IET): This allows Annex I Parties to "trade" emissions (measured as Assigned Amount Units or "allowances").
2. Clean Development Mechanism (CDM): This encourages emission reductions in non-Annex I countries.
3. Joint Implementation (JI): This encourages emission reductions in Annex I countries.

The cost of reducing emissions varies between countries. Studies suggested that using these mechanisms could lower the overall cost of meeting Kyoto targets and reduce economic losses in Annex I countries.

The CDM and JI are called "project-based mechanisms" because they create emission reductions through specific projects. Unlike IET, which sets a limit on total emissions, the CDM and JI focus on producing emission reductions. The CDM helps non-Annex I countries reduce emissions, while JI helps Annex I countries.

Emission reductions from the CDM and JI are compared to a hypothetical level of emissions that would have occurred without the project. These reductions are called "credits" and are measured as Certified Emission Reductions (CERs) for the CDM and Emission Reduction Units (ERUs) for JI.

Projects using nuclear energy are not eligible for CDM credits to prevent nuclear technology from becoming the main way to earn credits.

Each Annex I country must report yearly on human-caused greenhouse gas emissions and removals from natural sources under the UNFCCC and Kyoto Protocol. These countries appoint a "designated national authority" to manage their reports. Many non-Annex I countries also have a designated national authority to handle their Kyoto obligations, especially for the CDM process.

Emissions trading sets a total limit on emissions for all participating countries. If a country emits more than its limit, it must buy extra emissions rights from countries that emit less. This can reduce the use of fossil fuels, which are a major cause of climate change, and encourage investments in renewable energy like wind and solar power.

However, emissions trading systems often do not align with global goals to keep warming below 1.5°C or "well below" 2°C. This can lead to a surplus of emission allowances, which lowers their value and has little impact on reducing fossil fuel use. Prices for emission allowances vary widely, from €7 per tonne of CO₂ in China’s system to €63 per tonne in the EU Emissions Trading Scheme (EU-ETS) as of September 2021.

Other greenhouse gases can be traded, but their value is calculated as multiples of carbon dioxide based on their global warming potential.

An international effort to create a global carbon market with a gradually decreasing emissions cap began at COP30. This could reduce emissions seven times faster in participating countries and provide $200 billion annually for clean energy and social programs.

The European Union Emissions Trading Scheme (EU ETS) allows countries to trade Kyoto obligations with each other. However, no direct emissions trading between governments outside the EU ETS has occurred.

A problem with IET is the large number of unused emission allowances. Countries like Russia, Ukraine, and some EU members have surplus allowances, while many OECD countries have a shortage. Some surplus countries see these allowances as compensation for economic changes. The surplus has been called "hot air," a term Russia finds offensive.

OECD countries with a shortage could buy allowances from surplus countries to meet their Kyoto goals. However, this trade might not reduce overall emissions unless steps are taken to reduce the surplus.

The Green Investment Scheme (GIS) is a plan to use surplus emission allowances (AAUs) from the Kyoto Protocol to fund environmental projects. The GIS allows countries with surplus allowances to sell them to others, with the money used for green projects. However, the GIS is not required by the Kyoto Protocol, and there is no official definition of the term.

Details of the agreement

The agreement is a protocol to the United Nations Framework Convention on Climate Change (UNFCCC), which was created during the Earth Summit in Rio de Janeiro in 1992. This original agreement did not set legally binding limits on emissions or include ways to enforce rules. Only countries that are part of the UNFCCC can join the Kyoto Protocol. The Kyoto Protocol was adopted during the third meeting of the Conference of the Parties to the UNFCCC in 1997 in Kyoto, Japan.

The Kyoto Protocol sets specific emission reduction targets for participating countries. These targets do not include emissions from international aviation or shipping. Countries that join the Kyoto Protocol can use activities related to land use, land-use change, and forestry (LULUCF) to help meet their targets. These LULUCF activities are also called "sink" activities because they can absorb greenhouse gases. Changes in land use and sinks can affect the climate. A report by the Intergovernmental Panel on Climate Change estimates that land use changes since 1750 have contributed to one-third of global warming. Specific rules define what counts as "forestry" under the Kyoto Protocol.

Eligible LULUCF activities include forest management, cropland management, grazing land management, and revegetation. For Annex I Parties (industrialized countries), the use of forest management to meet targets is limited.

Under the Kyoto Protocol, 37 industrialized countries and the European Community (made up of 15 countries at the time of the Kyoto negotiations) agreed to legally binding targets for reducing greenhouse gas (GHG) emissions. These targets apply to six types of GHGs: carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), sulfur hexafluoride (SF₆), hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs). These gases are compared to CO₂ equivalents to calculate emission reductions. These targets apply separately from the reduction of industrial gases like chlorofluorocarbons (CFCs), which are addressed under the 1987 Montreal Protocol.

Only Annex I Parties are required to meet national or joint emission reduction targets, which are called "quantified emission limitation and reduction objectives" (QELRO) in Article 4.1 of the Kyoto Protocol. Non-Annex I Parties (mostly low-income developing countries) are not required to set their own targets but can participate through the Clean Development Mechanism (explained later).

Emission limits for Annex I Parties vary. Some countries must reduce emissions below their base year levels, some must keep emissions at base year levels, and others may increase emissions slightly. Emission limits do not include emissions from international aviation or shipping. Belarus and Turkey are listed in Annex I but do not have emission targets because they were not Annex I Parties when the Kyoto Protocol was adopted. Kazakhstan is not required to set a target but has expressed a desire to join Annex I.

Examples of emission reduction targets for Annex I Parties include:
– Australia: 108% (2.1% of 1990 emissions)
– Austria: 87%
– Belarus: 95% (subject to acceptance by other parties)
– Belgium: 92.5%
– Bulgaria: 92% (0.6%)
– Canada: 94% (3.33%) (withdrew)
– Croatia: 95%
– Czech Republic: 92% (1.24%)
– Denmark: 79%
– Estonia: 92% (0.28%)
– Finland: 100%
– France: 100%
– Germany: 79%
– Greece: 125%
– Hungary: 94% (0.52%)
– Iceland: 110% (0.02%)
– Ireland: 113%
– Italy: 93.5%
– Japan: 94% (8.55%)
– Latvia: 92% (0.17%)
– Liechtenstein: 92% (0.0015%)
– Lithuania: 92%
– Luxembourg: 72%
– Netherlands: 94%
– New Zealand: 100% (0.19%)
– Norway: 101% (0.26%)
– Poland: 94% (3.02%)
– Portugal: 92%
– Romania: 92% (1.24%)
– Russian Federation: 100% (17.4%)
– Slovakia: 92% (0.42%)
– Slovenia: 92%
– Spain: 115%
– Sweden: 104%
– Switzerland: 92% (0.32%)
– Ukraine: 100%
– United Kingdom: 87.5%
– United States of America: 93% (36.1%) (non-party)

For most countries, 1990 is the base year used to calculate emission reductions. However, five countries use different base years:
– Bulgaria: 1988
– Hungary: average of 1985–1987
– Poland: 1988
– Romania: 1989
– Slovenia: 1986

Annex I Parties can use various methods, called "flexibility mechanisms," to meet their targets. These include allowing major operators within their borders to reduce emissions or offset excess emissions by purchasing credits from other operators.

Article 4.2 of the UNFCCC requires industrialized countries to "take the lead" in reducing emissions. The initial goal was to stabilize emissions at 1990 levels by 2000. The failure of some industrialized countries to meet this goal led to the Kyoto Protocol’s binding commitments.

At the first UNFCCC Conference of the Parties in Berlin, the G77 (a group of 133 developing countries) pushed for a "Berlin mandate" that recognized:
– Developed countries contributed most to current greenhouse gas levels.
– Developing countries had lower per-person emissions.
– Developing countries would need to increase emissions to meet their development needs.

China was not part of the G77 at the time but later joined. The Kyoto Protocol did not require developing countries to set emission reduction targets during the first

Ratification process

The Kyoto Protocol was adopted by COP 3 of the UNFCCC on December 11, 1997, in Kyoto, Japan. It was open for signing from March 16, 1998, to March 15, 1999. During this time, countries such as Antigua and Barbuda, Argentina, the Maldives, Samoa, St. Lucia, and Switzerland signed the agreement. At the end of the signing period, 82 countries and the European Community had signed. To become a party to the Protocol, countries needed to ratify it. Ratification began on September 17, 1998, when Fiji ratified the agreement. Countries that did not sign could still join the Protocol by acceding to it, which has the same legal effect as signing.

Article 25 of the Protocol states that it will take effect on the ninetieth day after the date when at least 55 countries that are part of the UNFCCC, including those in Annex I (which together account for at least 55% of carbon dioxide emissions from Annex I countries in 1990), have submitted their instruments of ratification, acceptance, approval, or accession.

The European Union and its member states ratified the Protocol in May 2002. The "55 parties" condition was met on May 23, 2002, when Iceland ratified the Protocol. Russia ratified the Protocol on November 18, 2004, meeting the "55%" condition. This caused the treaty to take effect on February 16, 2005, after the required 90-day period.

As of May 2013, 191 countries and one regional economic organization (the European Community) had ratified the agreement. These countries represent over 61.6% of the 1990 emissions from Annex I countries. One of the 191 ratifying states, Canada, has renounced the Protocol.

The following countries have ratified the agreement: Afghanistan, Albania, Algeria, Angola, Antigua and Barbuda, Argentina, Armenia, Australia, Austria, Azerbaijan, Bahamas, Bahrain, Bangladesh, Barbados, Belarus, Belgium, Belize, Benin, Bhutan, Bolivia, Bosnia and Herzegovina, Botswana, Brazil, Brunei, Bulgaria, Burkina Faso, Myanmar, Burundi, Cambodia, Cameroon, Canada, Cape Verde, Central African Republic, Chad, Chile, China, Colombia, Comoros, Democratic Republic of the Congo, Republic of the Congo, Cook Islands, Costa Rica, Ivory Coast, Croatia, Cuba, Cyprus, Czech Republic, Denmark, Djibouti, Dominica, Dominican Republic, Ecuador, East Timor, Egypt, El Salvador, Equatorial Guinea, Eritrea, Estonia, Eswatini, Ethiopia, European Union, Fiji, Finland, France, Gabon, Gambia, Georgia, Germany, Ghana, Greece, Grenada, Guatemala, Guinea, Guinea-Bissau, Guyana, Haiti, Honduras, Hungary, Iceland, India, Indonesia, Iran, Iraq, Ireland, Israel, Italy, Jamaica, Japan, Jordan, Kazakhstan, Kenya, Kiribati, North Korea, South Korea, Kuwait, Kyrgyzstan, Laos, Latvia, Lebanon, Lesotho, Liberia, Libya, Liechtenstein, Lithuania, Luxembourg, Madagascar, Malawi, Malaysia, Maldives, Mali, Malta, Marshall Islands, Mauritania, Mauritius, Mexico, Federated States of Micronesia, Moldova, Monaco, Mongolia, Montenegro, Morocco, Mozambique, Namibia, Nauru, Nepal, Netherlands, New Zealand, Nicaragua, Niger, Nigeria, Niue, North Macedonia, Norway, Oman, Pakistan, Palau, Panama, Papua New Guinea, Paraguay, Peru, Philippines, Poland, Portugal, Qatar, Romania, Russia, Rwanda, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Samoa, San Marino, São Tomé and Príncipe, Saudi Arabia, Senegal, Serbia, Seychelles, Sierra Leone, Singapore, Slovakia, Slovenia, Solomon Islands, Somalia (non-party to Kyoto), South Africa, Spain, Sri Lanka, Sudan, Suriname, Sweden, Switzerland, Syria, Tajikistan, Tanzania, Thailand, Togo, Tonga, Trinidad and Tobago, Tunisia, Turkey, Turkmenistan, Tuvalu, Uganda, Ukraine, United Arab Emirates, United Kingdom, United States (non-party to Kyoto), Uruguay, Uzbekistan, Vanuatu, Venezuela, Vietnam, Yemen, Zambia, Zimbabwe.

Andorra (non-party to Kyoto) and the Holy See (non-party to Kyoto) are also listed.

The United States signed the Protocol on November 12, 1998, during the Clinton administration. However, for the treaty to become legally binding in the US, it needed to be approved by the Senate. The Senate had already passed the 1997 non-binding Byrd-Hagel Resolution, which expressed disapproval of any international agreement that did not require developing countries to reduce emissions and claimed the Protocol would harm the US economy. The resolution passed 95–0. As a result, the Clinton administration signed the treaty, but it was never submitted to the Senate for approval.

At the start of the Bush administration, Senators Chuck Hagel, Jesse Helms, Larry Craig, and Pat Roberts wrote to President George W

Country types and their emissions

Total greenhouse gas (GHG) emissions, not including emissions from land use, land use change, and forestry (LULUCF), for all Annex I Parties (including the United States) decreased from 19.0 to 17.8 thousand teragrams (Tg, which is equal to 10^9 kg) CO2 equivalent between 1990 and 2008. This represents a 6.0% decline over this period. Several factors contributed to this decrease. One factor is the economic restructuring in the Annex I Economies in Transition (EITs). Between 1990 and 1999, emissions in EITs dropped by 40% after the collapse of central planning in former Soviet Union and Eastern European countries. This led to a major reduction in heavy industry, which lowered fossil fuel use and emissions.

Emissions growth among Annex I Parties was also limited by policies and measures (PaMs). After 2000, these policies improved energy efficiency and expanded renewable energy use. Energy use also decreased during the 2007–2008 economic crisis.

Annex I countries (excluding the United States) committed to a Kyoto target: reducing average GHG emissions by 4.2% between 2008 and 2012 compared to 1990 levels.

As noted earlier, emissions from EITs dropped significantly between 1990 and 1999. This reduction was a major reason for the overall decrease in Annex I emissions (excluding the United States). Emissions from Annex II countries (Annex I countries excluding EITs) increased slightly from 1990 to 2006 but then stabilized and decreased after 2007. Emissions reductions by 12 EIT countries that joined the EU helped the EU-27 meet its Kyoto target.

In December 2011, Canada’s environment minister announced the country would leave the Kyoto agreement after the 2011 United Nations Climate Change Conference.

Belarus, Malta, and Turkey are Annex I Parties but did not have Kyoto targets in the first round. The United States had a target of reducing emissions by 7% compared to 1990 levels but did not ratify the treaty. If the United States had ratified the Kyoto Protocol, the average GHG reduction for Annex I countries would have been 5.2% compared to 1990 levels.

The UNFCCC (2005) collected information from non-Annex I Parties. Most of these countries were low-income, with few classified as middle-income. Many provided details about policies related to sustainable development, such as reducing poverty and improving education and healthcare. Many non-Annex I countries are updating environmental laws to address global issues like climate change.

Some countries, such as South Africa and Iran, expressed concerns that efforts by Annex I countries to reduce emissions might harm their economies, which rely heavily on fossil fuel production and exports.

GHG emissions, excluding land use change and forestry (LUCF), reported by 122 non-Annex I Parties for 1994 or the closest available year, totaled 11.7 billion tonnes of CO2 equivalent. CO2 made up the largest share (63%), followed by methane (26%) and nitrous oxide (11%).

The energy sector was the largest source of emissions for 70 Parties, while the agriculture sector was the largest for 45 Parties. Average per capita emissions (excluding LUCF) for the 122 non-Annex I Parties were 2.8 tonnes of CO2 equivalent.

• The Africa region had total emissions of 1.6 billion tonnes, with per capita emissions of 2.4 tonnes.
• The Asia and Pacific region had total emissions of 7.9 billion tonnes, with per capita emissions of 2.6 tonnes.
• The Latin America and Caribbean region had total emissions of 2 billion tonnes, with per capita emissions of 4.6 tonnes.
• The "other" region, which includes Albania, Armenia, Azerbaijan, Georgia, Malta, Moldova, and North Macedonia, had total emissions of 0.1 billion tonnes, with per capita emissions of 5.1 tonnes.

Parties reported high uncertainty in LUCF emissions. However, overall, including LUCF added only a small difference (1.7%) to total emissions. With LUCF, total emissions were 11.9 billion tonnes, and without LUCF, total emissions were 11.7 billion tonnes.

Problem areas

Gupta et al. (2007) reviewed the research on climate change policy. They found that no official evaluations of the UNFCCC or its Protocol claimed these agreements had or would solve the climate problem. In these studies, it was assumed the UNFCCC or its Protocol would not be changed. The Framework Convention and its Protocol include rules for future policy actions to be taken.

Gupta et al. (2007) described the Kyoto first-round commitments as "modest," noting they limited the treaty’s effectiveness. It was suggested that later Kyoto commitments could be more effective if they included deeper emission cuts and applied to a larger share of global emissions. In 2008, countries with a Kyoto cap made up less than one-third of annual global carbon dioxide emissions from fuel combustion.

The World Bank (2010) noted that the Kyoto Protocol had only a small effect on slowing global emissions growth. The treaty was created in 1997, but by 2006, energy-related carbon dioxide emissions had increased by 24%. The World Bank also stated the treaty provided limited financial help to developing countries to reduce emissions and adapt to climate change.

Some environmentalists supported the Kyoto Protocol because it was "the only game in town" and because they expected future emission reduction goals might require stricter cuts (Aldy et al., 2003, p. 9). In 2001, seventeen national science academies said ratifying the Protocol was a "small but essential first step" toward stabilizing greenhouse gas levels. Others criticized the current commitments for being too weak (Grubb, 2000, p. 5).

The United States (under former President George W. Bush) and Australia (initially, under former Prime Minister John Howard) did not ratify the Kyoto treaty. According to Stern (2006), their decision was based on the lack of emission limits for emerging economies. Australia later ratified the treaty under former Prime Minister Kevin Rudd, which took effect in March 2008.

Thirty-eight developed countries committed to limiting greenhouse gas emissions. Because the United States did not ratify and Canada withdrew, the emission limits applied to 36 countries. All of them followed the Protocol. However, nine countries (Austria, Denmark, Iceland, Japan, Lichtenstein, Luxembourg, Norway, Spain, and Switzerland) used flexibility mechanisms because their emissions slightly exceeded their targets.

In total, the 36 countries that fully participated in the Protocol aimed to reduce their combined emissions by 4% from the 1990 base year. Their average annual emissions in 2008–2012 were 24.2% lower than in 1990. This means they met their goal by a large margin. If the United States and Canada were included, emissions decreased by 11.8%. These reductions were mainly due to the collapse of the Soviet Union, which cut emissions in Eastern Bloc countries by tens of percent in the early 1990s. The 2008 financial crisis also reduced emissions during the first Kyoto commitment period.

The 36 countries that committed to emission reductions accounted for 24% of global greenhouse gas emissions in 2010. Even though these countries reduced their emissions significantly during the Kyoto period, other countries increased their emissions so much that global emissions rose by 32% from 1990 to 2010.

In several large developing countries and fast-growing economies (China, India, Thailand, Indonesia, Egypt, and Iran), greenhouse gas emissions increased rapidly (PBL, 2009). For example, China’s emissions rose strongly between 1990 and 2005, often by more than 10% each year. Per-person emissions in non-Annex I countries are still much lower than in industrialized countries. Non-Annex I countries do not have specific emission reduction targets but are committed to taking steps to reduce emissions. China, for example, has a national plan to slow emissions growth, including closing outdated, inefficient coal-fired power plants.

The role of Kyoto’s flexibility mechanisms—carbon trading, Joint Implementation, and the Clean Development Mechanism (CDM)—has been discussed. Supporters say these mechanisms help Annex I countries meet their Kyoto goals at lower costs. Critics argue that emissions trading does not encourage investment in clean energy and that CDM projects can harm local communities in developing countries.

China, India, Indonesia, and Brazil were not required to reduce their CO₂ emissions. Other signatory countries were not obligated to follow a common framework or specific measures but had to meet emission reduction targets that allowed them to buy carbon credits from each other. The Emissions-trading Scheme (ETS) enabled countries to host polluting industries and purchase environmental benefits from other countries.

A 2021 review examined the design of the Kyoto Protocol and the political strategies that influenced its adoption. It concluded that the Protocol’s limited impact on global emissions reflects factors such as "deliberate political strategy, unequal power, and the absence of leadership" among and within nations. Efforts by fossil fuel interests and conservative think tanks to spread misinformation and deny climate change have affected public opinion and political action in the United States and elsewhere. Direct lobbying by fossil fuel companies and their funding of political figures have slowed climate action at local, national, and international levels.

Amendment and successor

In the "Washington Declaration," which is not legally required, leaders of governments from Canada, France, Germany, Italy, Japan, Russia, the United Kingdom, the United States, Brazil, China, India, Mexico, and South Africa agreed on the main idea of a new agreement to replace the Kyoto Protocol. They planned a global system that would set limits on carbon emissions and allow trading of emissions rights for both developed and developing countries. They initially hoped this system would be in place by 2009.

The United Nations Climate Change Conference in Copenhagen in December 2009 was one of the yearly meetings organized by the UN after the 1992 Earth Summit in Rio. In 1997, these talks led to the Kyoto Protocol. The Copenhagen meeting was seen as a chance to create a new agreement to replace Kyoto and achieve significant reductions in carbon emissions.

The 2010 Cancún agreements included voluntary commitments from 76 developed and developing countries to control their greenhouse gas emissions. In 2010, these 76 countries were together responsible for 85% of the world's yearly emissions.

By May 2012, the United States, Japan, Russia, and Canada said they would not join a second Kyoto commitment period. In November 2012, Australia confirmed it would participate in a second Kyoto commitment period, while New Zealand said it would not.

New Zealand's climate minister, Tim Groser, stated the 15-year-old Kyoto Protocol was outdated and that New Zealand was "taking early steps" to find a replacement that includes developing nations. Groups that protect the environment, such as the World Wildlife Fund, criticized New Zealand's decision to leave the Kyoto Protocol.

On 8 December 2012, at the end of the 2012 United Nations Climate Change Conference, an agreement was reached to extend the Kyoto Protocol until 2020 and to set 2015 as the year to create a new agreement, which would begin in 2020. The outcome of the Doha talks received mixed reactions, with small island nations expressing concerns about the overall plan. The second Kyoto commitment period covers about 11% of the world's yearly greenhouse gas emissions. Other results of the conference included a schedule for a global agreement to be adopted by 2015, involving all countries. At the Doha meeting, the European Union's chief climate negotiator, Artur Runge-Metzger, promised to extend the Kyoto Protocol, which is legally required for the 27 European Union countries, until 2020, pending approval within the EU.

Ban Ki-Moon, the Secretary General of the United Nations, urged world leaders to reach an agreement to stop global warming during the 69th Session of the UN General Assembly on 23 September 2014 in New York. The next major climate meeting was held in Paris in 2015, which led to the creation of the Paris Agreement, the new agreement replacing the Kyoto Protocol.