The Western Climate Initiative (WCI) is a collaborative effort of seven U.S. states and four Canadian provinces to identify, evaluate, and implement measures to reduce greenhouse gas (GHG) emissions in participating jurisdictions. The WCI has a regional GHG target of 15 percent below 2005 levels by 2020 that will be met through a regional market-based multi-sector mechanism, as well as other policies. The recommended cap-and-trade program has a broad scope that includes six greenhouse gases (carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride) and will cover 90 percent of GHG emissions from the region when fully implemented. The cap-and-trade program will begin January 1, 2012.
Established in February 2007 by the governors of five western states, Arizona, California, New Mexico, Oregon, and Washington, the WCI has since grown to include two additional U.S. States, Utah and Montana, and four Canadian provinces, British Columbia, Manitoba, Ontario, and Quebec. An additional 14 jurisdictions participate as observers, including the U.S. states of Alaska, Colorado, Idaho, Kansas, Nevada, and Wyoming; the Canadian provinces of Nova Scotia and Saskatchewan; and the Mexican border states of Baja California, Chihuahua, Coahuila, Nuevo Leon, Sonora, and Tamaulipas.
July 27, 2010: The WCI released its Design for the WCI Regional Program , which is a comprehensive strategy to reduce greenhouse gas (GHG) emissions, stimulate development of clean-energy technologies, create green jobs, increase energy security, and protect public health. It details a plan to reduce regional GHG emissions to 15 percent below 2005 levels by 2020. The plan is the culmination of two years of work by seven U.S. states and four Canadian provinces and builds on the recommendations for a regional cap-and-trade program that the Partners released in September 2008. Read more 
September 23, 2008: The WCI released its Design Recommendations  for the regional market-based multi-sector program. The Design Recommendations set forth a cap-and-trade program with a broad scope to be implemented in two phases. The first phase begins on January 1, 2012 and will cover emissions from electricity and large industrial and commercial sources. The second phase will begin January 1, 2015 and will expand to cover emissions from transportation and residential, commercial, and industrial fuel use not otherwise covered. Read more 
July 23, 2008: Ontario joins WCI as a full Partner.
April 18, 2008: Quebec joins WCI as a full Partner.
January 4, 2008: Montana joins WCI as a full Partner.
August 22, 2007: The WCI announced its regional, economy-wide greenhouse gas emissions target  of 15 percent below 2005 levels by 2020, or approximately 33 percent below business-as-usual levels.
June 13, 2007: Manitoba joins the WCI as a full Partner.
May 21, 2007: Utah joins the WCI as a full Partner.
April 24, 2007: British Columbia joins the WCI as a full Partner.
February 26, 2007: Governors Napolitano of Arizona, Schwarzenegger of California, Richardson of New Mexico, Kulongoski of Oregon, and Gregoire of Washington signed an agreement establishing the Western Climate Initiative , a joint effort to reduce greenhouse gas emissions and address climate change.
Find out what's being done in other states  to combat climate change.