The Kyoto Protocol to the United Nations Framework Convention on Climate Change is an additional protocol adopted on 11 December 1997 to form the United Nations Framework Convention on Climate Change (UNFCCC) of climate protection. The agreement, which entered into force on 16 February 2005, establishes for the first time legally binding targets for the emission of greenhouse gases in industrialized countries, which are the main cause of global warming. By early December 2011, 191 states and the European Union had signed and ratified the Kyoto Protocol. The US rejected the ratification of the protocol in 2001, and Canada announced its withdrawal from the agreement on December 13.
