A group of four provinces and seven U.S. states announced their design for a cap-and-trade system to reduce greenhouse gas emissions.

The Western Climate Initiative, which includes Ontario, Quebec, Manitoba, British Columbia, Arizona, California, Montana, New Mexico, Oregon, Utah and Washington, released its design recommendations in a report today. It imagines a system launching Jan. 1, 2012.

Additional design work still needs to be done, the report indicates. The program published represents final high-level work. The governments’ next tasks will be to develop a work plan and schedule for that additional design work.

Ontario reports that it signed a Memorandum of Understanding with Quebec in June to work on the development of a cap-and-trade system for GHG emissions that could be in place as early as 2010. This collaboration is aimed at making links with broader North American and international cap-and-trade systems, such as WCI, and providing an intergovernmental forum between Canadian provinces and territories, it adds.

“Today is a milestone for Ontario’s efforts leading the way for a national cap-and-trade system. There is no question that we need to put a price on carbon, and more needs to be done,” said the province’s environment minister, John Gerretsen. “Ontario is committed to developing a strong cap-and-trade system to bring about real reductions in greenhouse gases.”