Check out this article from Bloomberg:
Chevron Corp. (CVX) helped write the first-in-the-nation rule ordering reduced carbon emissions from cars and trucks. Its biofuels chief spoke at the ceremony where California Governor Arnold Schwarzenegger signed the executive order in 2007, the same year the oil company pledged to develop a gasoline replacement from wood.
Now Chevron is leading a lobbying and public relations campaign to undercut the California mandate aimed at curbing global warming, two years after the state started phasing it in. Research on commercially viable climate-friendly products has come to naught, stymied by the poor economics of coaxing hydrocarbons from plants’ stubborn cell walls, according to Chevron officials.
The rest here: http://mobile.bloomberg.com/news/2013-04-18/chevron-defies-california-on-carbon-emissions.html