The formal waiver under the Clean Air Act allows California to require automakers to increase the efficiency of the vehicles they intend to sell in California by 40% over the next seven years, resulting in an average fuel economy of 35.5 miles per gallon by 2016.
President Obama proposed a national standard for automobiles in May that would largely mirror California's plan. Since many states have already signaled their intention to follow California's lead, today's decision could speed implementation of the national standard.
This would be good news for the auto industry, since they could focus on one standard rather than 50.
This national standard would be just the first step in the Obama administration's plan to expand regulation of pollution linked to climate change.
As I wrote last week, many corporate counsel in energy and manufacturing companies have already begun consulting with environmental experts to get a sense of their current greenhouse gas impact, and to explore ways of complying with the eventual regulations.