Protocol of Kyoto

The Protocol of Kyoto is a an international agreement, initially adopted in 1997, which started with the idea that greenhouse gas concentrations in the atmosphere should be reduced at a level that would prevent dangerous consequences to the planet. It was adopted on 11 December 1997 in Kyoto, Japan. 187 states have signed and ratified the protocol. So far the only country which has signed, but not ratified, the protocol is the United States of America.