The 1992 Earth Summit held in Rio de Janeiro, Brazil, produced a treaty aimed at reducing greenhouse gas emissions in order to combat global warming. Representatives of 172 nations agreed to work toward the sustainable development of the planet, although most of the agreements were not legally binding. In 1997, an amendment was negotiated called the Kyoto Protocol, by which participating nations commit to reduce their emissions of carbon dioxide. Which countries have not ratified the agreement? Discuss (http://forum.thefreedictionary.com/postst73753_Kyoto-Protocol-Comes-into-Force.aspx)