The Kyoto Protocol is an international treaty adopted in 1997 in Kyoto, Japan, aimed at combating climate change by reducing greenhouse gas emissions. It sets legally binding targets for developed countries to lower their emissions, recognizing their historical responsibility for climate change. The protocol also established mechanisms for countries to meet their targets, such as emissions trading and the Clean Development Mechanism (CDM). It came into force in 2005 and has been a significant framework in global climate policy, although its effectiveness and participation have been subjects of debate.