The international response to climate change was launched in 1992, at the Earth Summit in Rio de Janeiro, with the signing of the U.N. Framework Convention on Climate Change. The Convention established a long-term objective of stabilizing greenhouse concentrations in the atmosphere “at a level that would prevent dangerous anthropogenic interference with the climate system.” It also set a voluntary goal of reducing emissions from developed counties to 1990 levels by 2000 – a goal that most did not meet.
Recognizing that stronger action was needed, countries negotiated the 1997 Kyoto Protocol, which sets binding targets to reduce emissions 5.2 percent below 1990 levels by 2012. Although the United States has not signed on to Kyoto, more than 100 other nations have ratified it and many of the developed countries have begun efforts to meet their emissions targets. The Protocol legally entered into force on February 16, 2005.