Jumat, 23 Mei 2008

Climate Change

Global climate change refers to any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer). Global warming, a term which refers to an average increase in the temperature of the atmosphere near the Earth’s surface, can contribute to changes in global climate patterns and is influenced by both human activities and natural causes. One of the key contributors to global warming is the increased emissions of greenhouse gases (GHGs) resulting from human activities.

Human activities, such as the burning of fossil fuels, deforestation, and agricultural practices, have caused the concentrations of heat-trapping GHGs to increase significantly in the atmosphere. Since the beginning of the industrial revolution, atmospheric concentrations of greenhouse gases (GHGs) have increased at an accelerating pace because of human activities. According to the 2007 findings of the Intergovernmental Panel on Climate Change, concentrations of carbon dioxide (CO) have increased 35%, methane (CH4) concentrations have increase almost 150%, and nitrous oxide (N2O) concentrations have risen by 18% since the pre-industrial era. These increases have enhanced the heat-trapping capability of the earth's atmosphere. According to NOAA and NASA data, the Earth’s average surface temperature has increased by about 1.2 to 1.4 degrees since 1900. There is general consensus among the world’s leading climate modelers that the buildup of GHGs will lead to further increases in the worldwide average temperature, with potential impacts that may include rising sea levels, erosion of coast lines, increased storm intensity, changing rainfall patterns, and loss and migration of species.

In 1993, most world countries joined an international treaty -- the United Nations Framework Convention on Climate Change (UNFCCC) -- to begin to consider what can be done to reduce global warming and to cope with whatever temperature increases are inevitable. In 2005, an addition to the treaty known as the Kyoto Protocol formally entered into force. The Kyoto Protocol contains quantified, country-specific emission reduction targets for the period of 2008-2012 and legally binding commitments to these reductions for 36 countries. In January 2005 the European Union Greenhouse Gas Emission Trading Scheme (EU ETS) commenced operation as the largest multi-country, multi-sector Greenhouse Gas emission trading scheme world-wide. The aim of the EU ETS is to help EU Member States achieve compliance with their commitments under the Kyoto Protocol. The Prototype Carbon Fund, a partnership between seventeen companies and six governments and managed by the World Bank, became operational in April 2000. This fund helps establish the market for project-based greenhouse gas emission reductions while promoting sustainable development.

In 2004, the international Methane to Markets Partnership was launched as a voluntary, non-binding framework for international cooperation to advance the recovery and use of methane as a valuable clean energy source. Under the Partnership, countries make formal declarations to minimize methane emissions from key sources, stressing the importance of implementing methane capture and use projects in developing countries and countries with economies in transition. The Asia-Pacific Partnership on Clean Development and Climate is an innovative new effort to accelerate the development and deployment of clean energy technologies.

There have also been a number of regional, state and local initiatives to address climate change in the United States. In 2005, Governors of seven Northeast States signed a Memorandum of Understanding to develop a CO2 cap and trade initiative known as the Regional Greenhouse Gas Initiative (RGGI). In 2006, California became the first state to pass a comprehensive GHG emission reduction regulation under legislative bill AB32, which has the potential to cover a wide range of source categories depending on how significant sources are ultimately defined. The recently established national Climate Change Registry is a collaboration between states, provinces and tribes aimed at developing and managing a common GHG emissions reporting system that is capable of supporting various GHG emission reporting and reduction policies for its member states and tribes and reporting entities. Many states have also developed their own individual climate change action plans to identify and implement specific activities and responses to potential climate change impacts within their states.



Source : http://www.cleanairworld.org/TopicDetails.asp?parent=19

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