Aug. 23, 2007 -- California Gov. Arnold Schwarzenegger and five other Western governors, joined by two Canadian provincial leaders, have pledged to enforce a tough regional cap on greenhouse gas emissions.

Under the Western Climate Initiative, the leaders agreed to slash emissions of carbon dioxide and other climate-warming pollutants to 15% below 2005 levels in their states and provinces in the next 13 years.

To achieve their goal, the partners, including Democratic and Republican governors, committed to designing a carbon-trading system within a year.

The states that have signed up are Arizona, California, New Mexico, Oregon, Washington and Utah. Canadian provinces British Columbia and Manitoba have also joined the effort. Several states and provinces are official "observers," still considering whether to commit to the initiative's stringent goals. They include: Colorado; Kansas; Nevada; Wyoming; Ontario and Quebec, Canada; and Sonora, Mexico.

- From the Los Angeles Times