Which treaty adopted in 1997 set binding targets for greenhouse-gas reductions?

The Kyoto Protocol, adopted in 1997, set binding targets for greenhouse-gas reductions.

The protocol was adopted on 11 December 1997 at the United Nations climate conference in Kyoto, Japan. It entered into force on 16 February 2005 after enough countries had ratified it. Its central principle required industrialized countries and economies in transition to accept quantified emissions limits, reflecting the idea of common but differentiated responsibilities.

The first commitment period covered 2008 to 2012. The Doha Amendment created a second commitment period for 2013 to 2020, although participation and ratification were more limited. The United States signed but never ratified the original protocol.

The Paris Agreement, adopted in 2015, replaced the Kyoto framework with a broader system in which nearly all countries submit national climate plans. The Montreal Protocol instead addresses ozone-depleting substances, making it a different environmental treaty.