The Kyoto Protocol on global warming is an amendment to the 1992 United Nations Framework Convention on Climate Change (UNFCCC), more popularly known as the Rio Treaty.
Whereas the Rio Treaty set voluntary goals for reducing greenhouse gases, the Protocol requires participating developed countries to reduce their greenhouse emissions by 5.2 percent of 1990 levels by 2012. The United States withdrew from the Kyoto Protocol last year, but remains a party to the 1992 Rio Treaty.
The Protocol goes into effect when no fewer than 55 parties to the UNFCCC accounting for at least 55 percent of the total carbon dioxide emissions for 1990 have ratified, accepted, approved, or acceded to the Protocol.
As of September 27, 2002 95 countries accounting for a total of 37.1 percent of global man-made carbon dioxide emissions had ratified the Protocol. Russia (with 17 percent of global emissions) and Canada (with 3 percent) had pledged to ratify the Protocol at the recently concluded World Summit on Sustainable Development in Johannesburg, South Africa, but did not.