The Kyoto protocol is a subdocument to the United Nations Framework Convention on Climate Change (UNFCCC; created in Rio de Janeiro in 1992). The Kyoto protocol was created at the third session of the UNFCCC in 1997 in Kyoto, Japan to reduce the emissions of greenhouse gases into the atmosphere.
The Kyoto protocol will become active 90 days after that at least 55 parties of the UNFCCC have ratified it. These parties must also represent at least 55% of the total carbon dioxide emissions for 1990 from that group.
After George W. Bush was elected president of the United States in 2000, he stated that he would not follow the Kyoto protocol (previously signed by Bill Clinton, but not ratified) if doing so meant significant costs ("the American way of life is not negotiable").
Since the US is responsible for about 36% of all greenhouse gases (but only for 5% of the world's population), this has a major impact on the implementation of the Kyoto protocol.
In 2001, there was a new round of negotiations in Bonn where a new agreement was finally reached. After some concessions, the supporters of the protocol (led by the European Union) managed to get Japan and Russia in as well by allowing more use of CO2 sinks.
See also: Environmental agreements
From the CIA World Factbook:
Kyoto Protocol to the United Nations Framework Convention on Climate Change
note - abbreviated as Climate Change-Kyoto Protocol
opened for signature - 16 March 1998, but not yet in force
objective - to further reduce greenhouse gas emissions by enhancing the national programs of developed countries aimed at this goal and by establishing percentage reduction targets for the developed countries
parties - (21) Antigua and Barbuda, The Bahamas, Bolivia, Cyprus, El Salvador, Fiji, Georgia, Guatemala, Jamaica, Maldives, Federated States of Micronesia, Mongolia, Nicaragua, Niue, Palau, Panama, Paraguay, Trinidad and Tobago, Turkmenistan, Tuvalu, Uzbekistan
countries that have signed, but not yet ratified - (69) Argentina, Australia, Austria, Belgium, Brazil, Bulgaria, Canada, Chile, China, Cook Islands, Costa Rica, Croatia, Cuba, Czech Republic, Denmark, Ecuador, Egypt, Estonia, European Union, Finland, France, Germany, Greece, Honduras, Indonesia, Ireland, Israel, Italy, Japan, Kazakhstan, South Korea, Latvia, Liechtenstein, Lithuania, Luxembourg, Malaysia, Mali, Malta, Marshall Islands, Mexico, Monaco, Netherlands, New Zealand, Niger, Norway, Papua New Guinea, Peru, Philippines, Poland, Portugal, Romania, Russia, Saint Lucia, Saint Vincent and the Grenadines, Samoa, Seychelles, Slovakia, Slovenia, Solomon Islands, Spain, Sweden, Switzerland, Thailand, Ukraine, United Kingdom, United States, Uruguay, Vietnam, Zambia