The Environmental Protection Agency
has long been reluctant to limit greenhouse gas emissions and until the Supreme Court ruled that they had the authority to do so they made no moves in that direction. The state of California has been trying to implement their own greenhouse gas emissions limits but they need a waiver from the federal EPA
to do so. California Gov. Arnold Schwarzenegger has said he would sue the federal agency if they did not rule on the issue by October 22, but EPA Administrator Stephen Johnson told Reuters this week that they were on their own schedule that would yield a decision by the end of the year.
The state initially applied for the waiver in December 2005 but the EPA didn't even hold a hearing until 2007. The EPA is going through over 100,000 comment letters on the issue and if they give the state permission to move forward it will effectively result in higher fuel economy
standards in California and other states that follow suit.