In 1992, concern over rising, human-induced greenhouse gas concentrations in the atmosphere prompted the United Nations Framework Convention on Climate Change (UNFCCC) treaty at the Earth Summit in Rio de Janeiro. It designates sovereign states (political associations with independent authority over a geographical area and its human population) as either developing, Annex I industrialized states, or Annex II developed states and encourages signatories to take measures that anticipate, prevent, or minimize the causes of climate change and that mitigate its adverse effects, but all such measures are voluntary.
Concerned states convened in Kyoto, Japan in 1997 and drafted the Kyoto Protocol to set legally binding commitments for the UNFCCC.  The Kyoto Protocol entered into force in 2005, after ratification by over 55 states, including enough Annex I states to account for more than 55% of the world’s 1990 CO2 emissions. As of 2009, 184 states have ratified it. A notable exception is the United States, which signed, but has not ratified the treaty. The Kyoto Protocol specifies a number of requirements for its contracting parties (states that ratify the treaty) :
• All parties should implement programs that mitigate and adapt to climate change.
• Annex I parties must provide detailed inventories of their current greenhouse emissions as well as their emissions in 1990 that serves as the baseline for comparison.
• Annex I parties between 2008 and 2012 must limit their greenhouse gas emissions to a rate that varies from 10% higher (e.g., Iceland) to 8% lower (e.g., European Union) than their rate in 1990, depending on the state.
• Annex I parties may trade emission credits, whereby Annex I parties that emit less than their assigned amount may sell any surplus to Annex I parties that emit more than their assigned amount, a mechanism called joint implementation.
• Annex I parties may also gain emission credits through a clean development mechanism in which they sponsor projects in a non–Annex I party that mitigate greenhouse gas emissions.
• The first session of an annual Conference of the Parties shall approve mechanisms to determine and address cases of noncompliance with the provisions of the Kyoto Protocol, including a list of consequences.
• In subsequent years, the Conference of the Parties shall review the commitments of states in light of new scientific findings and experience gained in implementing climate-change policies.
The Conference of the Parties to the Kyoto Protocol also established a Compliance Committee
From 1990 to 2005, many of the Annex I parties met their commitments to reduce greenhouse gas emissions; however, total emissions grew about 24% worldwide. Current implementation of the Kyoto Protocol does not limit emissions from developing states, and from 1990 to 2005, emissions from Turkey increased by 76%, from China by 65%, and from India by 54%. , , ,  Several Annex I parties are not close to meeting their commitments: Turkey was allowed to convert from Annex I to non–Annex I; emissions from Spain increased by 60% from 1990 to 2005, from Canada by 54%, from Portugal by 40%, from Greece and Ireland by 25% each, and from New Zealand by 23%.  The Kyoto Protocol has not yet imposed major sanctions for noncompliance.
Carbon emissions trading expanded under the Kyoto Protocol to a value of 64 billion $U.S.  and to a volume of 170 Mt carbon equivalents, or about 2% of the world’s total emissions. The United Kingdom purchases over half of the world’s carbon emission credits. The vast majority of emission credits support projects in China that diminish greenhouse gas emissions such as the construction of higher efficiency coal fired electric power plants.
 van Vuuren, D., F. Q. Zhou, B. de Vries, K. J. Jiang, C. Graveland, and L. Yun (2003) Energy and emission scenarios for China in the 21st century - exploration of baseline development and mitigation options. Energy Policy 31:369-387.
 Rogner, H.-H., D. Zhou, B. R., P. Crabbé, O. Edenhofer, B. Hare, L. Kuijpers, and M. Yamaguchi (2007) Introduction. In: Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Metz, B., O. R. Davidson, P. R. Bosch, R. Dave, and L. A. Meyer, eds. Cambridge University Press, New York. pp. 95-116.
 United Nations (2007) National Greenhouse Gas Inventory Data for the Period 1990–2005, New York, http://unfccc.int/resource/docs/2007/sbi/eng/30.pdf.
 Capoor, K. and P. Ambrosi (2008) State and Trends of the Carbon Market 2008, The World Bank, Washington, D.C., http://siteresources.worldbank.org/NEWS/Resources/State&Trendsformatted06May10pm.pdf.
This is an excerpt from the book Global Climate Change: Convergence of Disciplines by Dr. Arnold J. Bloom and taken from UCVerse of the University of California.
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