The Protocol to the United Nations Framework Convention on Climate Change (the 'Kyoto Protocol') 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 Kyoto Protocol had received 84 signatures.

Pursuant to its Article 22, the Kyoto Protocol is subject to ratification, acceptance, approval or accession by Parties to the United Nations Framework Convention on Climate Change (UNFCCC or ‘Convention’). Parties to the Convention that have not signed the Kyoto Protocol may accede to it at any time.

The Kyoto Protocol entered into force on 16 February 2005 in accordance with Article 23, that is on the ninetieth day after the date on which not less than 55 Parties to the Convention, incorporating Parties included in Annex I of the Convention which accounted in total for at least 55 % of the total carbon dioxide emissions for 1990 of the Parties included in Annex I, had deposited their instruments of ratification, acceptance, approval or accession.

Currently, there are 192 Parties (191 States and 1 regional economic integration organization) to the Kyoto Protocol to the UNFCCC.

The authoritative information on the status of approval, acceptance, accession and ratification of the Convention is provided by its Depositary, the Secretary-General of the United Nations, on the respective internet page of the United Nations Treaty Collection.