In 1992, 188 countries negotiated the U.N. Framework Convention on Climate Change (UNFCCC). The UNFCCC went into effect in 1993 after it was ratified by 50 nations, including the United States. The UNFCCC contains voluntary commitments by industrialized nations to reduce their greenhouse gas emissions to 1990 levels by 2000, a target that was not met. The ultimate objective of the UNFCCC is to achieve stabilization of GHG concentrations in the atmosphere at a level that would prevent dangerous man-made disruption of the global climate system. It also requires nations to report net emissions, including sources and sinks, and promotes technology transfer and other assistance to developing countries. In 1997, parties to the UNFCCC adopted the Kyoto Protocol, which contains mandatory emissions limits for industrialized countries covering the period 2008-2012. The U.S. never ratified the Protocol so it is not subject to its mandatory reduction requirements. In 2012, parties to the Kyoto Protocol agreed to a second commitment period to run 2013-2020. Furthermore, at international climate meetings in 2011 in Durban, South Africa, countries agreed to launch the Ad Hoc Working Group on the Durban Platform for Enhanced Action (ADP) with a mandate “to develop a protocol, another legal instrument or an agreed outcome with legal force under the Convention applicable to all Parties.” Countries participating in the ADP process, including the U.S., have agreed to propose target reductions in 2014 and complete negotiations during meetings scheduled for late 2015 in Paris. The outcome would enter into effect starting in 2020.