Photos: Green is the theme at Detroit auto show

At the upcoming 2008 North American International Auto Show in Detroit, General Motors will announce that it is investing in biofuels start-up Coskata in a bid to make E85--a blend of ethanol and gasoline--more widely available. GM has committed to making half of its new cars able to run on E85 or gasoline by 2012.

But that's just part of the splash GM hopes to make in alternative transportation and fuels. GM is also expected to show off a concept car called the Cadillac Provoq (pictured here at the Consumer Electronics Show). It runs on a hydrogen fuel cell and a lithium-ion battery. There is no release date yet.

Captions by CNET News.com's Martin LaMonica