The Protocol was initially adopted on 11 December 1997 in Kyoto, Japan, and entered into force on 16 February 2005. As of September 2011, 191 states have signed and ratified the protocol. The only remaining signatory not to have ratified the protocol is the United States. Other United Nations member states which did not ratify the protocol are Afghanistan, Andorra and South Sudan. In December 2011, Canada denounced the Protocol.
Under the Protocol, 37 countries ("Annex I countries") commit themselves to a reduction of four greenhouse gases (GHG) (carbon dioxide, methane, nitrous oxide, sulphur hexafluoride) and two groups of gases (hydrofluorocarbons and perfluorocarbons) produced by them, and all member countries give general commitments. At negotiations, Annex I countries (including the US) collectively agreed to reduce their greenhouse gas emissions by 5.2% on average for the period 2008-2012. This reduction is relative to their annual emissions in a base year, usually 1990. Since the US has not ratified the treaty, the collective emissions reduction of Annex I Kyoto countries falls from 5.2% to 4.2% below base year.
The main aim of the Kyoto Protocol is to contain emissions of the main anthropogenic (i.e., human-emitted) greenhouse gases (GHGs) in ways that reflect underlying national differences in GHG emissions, wealth, and capacity to make the reductions. The treaty follows the main principles agreed in the original 1992 UN Framework Convention. According to the treaty, in 2012, Annex I Parties who have ratified the treaty must have fulfilled their obligations of greenhouse gas emissions limitations established for the Kyoto Protocol's first commitment period (2008–2012).
The five principal concepts of the Kyoto Protocol are:
Commitments for the Annex I Parties. The main feature of the Protocol lies in establishing commitments for the reduction of greenhouse gases that are legally binding for Annex I Parties. The Annex I Parties took on legally binding commitments based on the Berlin Mandate, which was a part of UNFCCC negotiations leading up to the Protocol.
Implementation. In order to meet the objectives of the Protocol, Annex I Parties are required to prepare policies and measures for the reduction of greenhouse gases in their respective countries. In addition, they are required to increase the absorption of these gases and utilize all mechanisms available, such as joint implementation, the clean development mechanism and emissions trading, in order to be rewarded with credits that would allow more greenhouse gas emissions at home.
Minimizing Impacts on Developing Countries by establishing an adaptation fund for climate change.
Accounting, Reporting and Review in order to ensure the integrity of the Protocol.
Compliance. Establishing a Compliance Committee to enforce compliance with the commitments under the Protocol.
The Protocol to the United Nations Framework Convention on Climate Change (UNFCCC) was adopted at the third session of the Conference of the Parties (COP 3) in Kyoto, Japan, on 11 December 1997. In accordance with Article 24, it was open for signature from 16 March 1998 to 15 March 1999 at United Nations Headquarters, New York. By that date the Protocol had received 84 signatures.
Pursuant to Article 22, the Protocol is subject to ratification, acceptance, approval or accession by Parties to the UNFCCC. Parties to the UNFCCC that have not signed the Protocol may accede to it at any time.
The Protocol entered into force on 16 February 2005 in accordance with Article 23, that is the ninetieth day after the date on which not less than 55 Parties to the UNFCCC, incorporating Parties included in Annex I which accounted in total for at least 55 % of the total carbon dioxide emissions for 1990 of the Parties included in Annex I, have deposited their instruments of ratification, acceptance, approval or accession.
Currently, there are 193 Parties (192 States and 1 regional economic integration organization) to the Kyoto Protocol to the UNFCCC. The total percentage of Annex I Parties emissions is 63.7%.