What Is the Kyoto Protocol?

Jaenschwalde Coal-Fired Power Plant
Sean Gallup/Getty Images News/Getty Images

The Kyoto Protocol was an amendment to the United Nations Framework Convention on Climate Change (UNFCCC), an international treaty intended to bring countries together to reduce global warming and to cope with the effects of temperature increases that are unavoidable after 150 years of industrialization. The provisions of the Kyoto Protocol were legally binding on the ratifying nations and stronger than those of the UNFCCC.​

Countries that ratify the Kyoto Protocol agreed to reduce emissions of six greenhouse gases that contribute to global warming: carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, HFCs, and PFCs. The countries were allowed to use emissions trading to meet their obligations if they maintained or increased their greenhouse gas emissions. Emissions trading allowed nations that can easily meet their targets to sell credits to those that cannot.

Lowering Emissions Worldwide

The goal of the Kyoto Protocol was to reduce worldwide greenhouse gas emissions to 5.2 percent below 1990 levels between 2008 and 2012. Compared to the emissions levels that would occur by 2010 without the Kyoto Protocol, however, this target actually represented a 29 percent cut.

The Kyoto Protocol set specific emissions reduction targets for each industrialized nation but excluded developing countries. To meet their targets, most ratifying nations had to combine several strategies:

Most of the world’s industrialized nations supported the Kyoto Protocol. One notable exception was the United States, which released more greenhouse gases than any other nation and accounts for more than 25 percent of those generated by humans worldwide. Australia also declined.


The Kyoto Protocol was negotiated in Kyoto, Japan, in December 1997. It was opened for signature on March 16, 1998, and closed a year later. Under terms of the agreement, the Kyoto Protocol would not take effect until 90 days after it was ratified by at least 55 countries involved in the UNFCCC. Another condition was that ratifying countries had to represent at least 55 percent of the world’s total carbon dioxide emissions for 1990.

The first condition was met on May 23, 2002, when Iceland became the 55th country to ratify the Kyoto Protocol. When Russia ratified the agreement in November 2004, the second condition was satisfied, and the Kyoto Protocol entered into force on February 16, 2005.

As a U.S. presidential candidate, George W. Bush promised to reduce carbon dioxide emissions. Shortly after he took office in 2001, however, President Bush withdrew U.S. support for the Kyoto Protocol and refused to submit it to Congress for ratification.

An Alternate Plan

Instead, Bush proposed a plan with incentives for U.S. businesses to voluntarily reduce greenhouse gas emissions 4.5 percent by 2010, which he claimed would equal taking 70 million cars off the road. According to the U.S. Department of Energy, however, the Bush plan actually would result in a 30 percent increase in U.S. greenhouse gas emissions over 1990 levels instead of the 7 percent reduction the treaty requires. That’s because the Bush plan measures the reduction against current emissions instead of the 1990 benchmark used by the Kyoto Protocol.

While his decision dealt a serious blow to the possibility of U.S. participation in the Kyoto Protocol, Bush wasn’t alone in his opposition. Prior to negotiation of the Kyoto Protocol, the U.S. Senate passed a resolution saying the U.S. should not sign any protocol that failed to include binding targets and timetables for both developing and industrialized nations or that "would result in serious harm to the economy of the United States.”

In 2011, Canada withdrew from the Kyoto Protocol, but by the end of the first commitment period in 2012, a total of 191 countries had ratified the protocol. The scope of the Kyoto Protocol was extended by the Doha Agreement in 2012, but more importantly, the Paris Agreement was reached in 2015, bringing back Canada and the US in the international climate fight.


Advocates of the Kyoto Protocol claim that reducing greenhouse gas emissions is an essential step in slowing or reversing global warming and that immediate multinational collaboration is needed if the world is to have any serious hope of preventing devastating climate changes.

Scientists agree that even a small increase in the average global temperature would lead to significant climate and weather changes, and profoundly affect plant, animal, and human life on Earth.

Warming Trend

Many scientists estimate that by the year 2100 the average global temperature will increase by 1.4 degrees to 5.8 degrees Celsius (approximately 2.5 degrees to 10.5 degrees Fahrenheit). This increase represents a significant acceleration in global warming. For example, during the 20th century, the average global temperature increased only 0.6 degrees Celsius (slightly more than 1 degree Fahrenheit).

This acceleration in the build-up of greenhouse gases and global warming is attributed to two key factors:

  1. The cumulative effect of 150 years of worldwide industrialization; and
  2. Factors such as overpopulation and deforestation combined with more factories, gas-powered vehicles, and machines worldwide.

Action Needed Now

Advocates of the Kyoto Protocol argue that taking action now to reduce greenhouse gas emissions could slow or reverse global warming, and prevent or mitigate many of the most severe problems associated with it. Many view the U.S. rejection of the treaty as irresponsible and accuse President Bush of pandering to the oil and gas industries.

Because the United States accounts for so many of the world’s greenhouse gases and contributes so much to the problem of global warming, some experts have suggested that the Kyoto Protocol cannot succeed without U.S. participation.


Arguments against the Kyoto Protocol generally fall into three categories: it demands too much; it achieves too little, or it is unnecessary.

In rejecting the Kyoto Protocol, which 178 other nations had accepted, President Bush claimed that the treaty requirements would harm the U.S. economy, leading to economic losses of $400 billion and costing 4.9 million jobs. Bush also objected to the exemption for developing nations. The president’s decision brought heavy criticism from U.S. allies and environmental groups in the U.S. and around the world.

Kyoto Critics Speak Out

Some critics, including a few scientists, are skeptical of the underlying science associated with global warming and say there is no real evidence that Earth’s surface temperature is rising due to human activity. For example, Russia’s Academy of Sciences called the Russian government's decision to approve the Kyoto Protocol "purely political," and said that it had "no scientific justification."

Some opponents say the treaty doesn’t go far enough to reduce greenhouse gases, and many of those critics also question the effectiveness of practices such as planting forests to produce emissions trading credits that many nations are relying on to meet their targets. They argue that planting forests may increase carbon dioxide for the first 10 years owing to new forest growth patterns and the release of carbon dioxide from the soil.

Others believe that if industrialized nations reduce their need for fossil fuels, the cost of coal, oil, and gas will go down, making them more affordable for developing nations. That would simply shift the source of the emissions without reducing them.

Finally, some critics say the treaty focuses on greenhouse gases without addressing population growth and other issues that affect global warming, making the Kyoto Protocol an anti-industrial agenda rather than an effort to address global warming. One Russian economic policy advisor even compared the Kyoto Protocol to fascism.

Where It Stands

Despite the Bush Administration’s position on the Kyoto Protocol, grassroots support in the U.S. remains strong. By June 2005, 165 U.S. cities had voted to support the treaty after Seattle led a nationwide effort to build support, and environmental organizations continue to urge U.S. participation.

Meanwhile, the Bush Administration continues to seek alternatives. The U.S. was a leader in forming the Asia-Pacific Partnership for Clean Development and Climate, an international agreement announced July 28, 2005 at a meeting of the Association of South East Asian Nations (ASEAN).

The United States, Australia, India, Japan, South Korea, and the People’s Republic of China agreed to collaborate on strategies to cut greenhouse gas emissions in half by the end of the 21st century. ASEAN nations account for 50 percent of the world’s greenhouse gas emissions, energy consumption, population, and GDP. Unlike the Kyoto Protocol, which imposes mandatory targets, the new agreement allows countries to set their own emissions goals, but with no enforcement.

At the announcement, Australian Foreign Minister Alexander Downer said the new partnership would complement the Kyoto agreement: “I think climate change is a problem and I don't think Kyoto is going to fix it...I think we've got to do so much more than that.”

Looking Ahead

Whether you support U.S. participation in the Kyoto Protocol or oppose it, the status of the issue is unlikely to change soon. President Bush continues to oppose the treaty, and there is no strong political will in Congress to alter his position, although the U.S. Senate voted in 2005 to reverse its earlier prohibition against mandatory pollution limits.

The Kyoto Protocol will go forward without U.S. involvement, and the Bush Administration will continue to seek less demanding alternatives. Whether they will prove to be more or less effective than the Kyoto Protocol is a question that won’t be answered until it may be too late to plot a new course.

Edited by Frederic Beaudry