As world leaders debate how to best reduce carbon emission and its effect on global warming, auto company executives have radically changed their attitude about their role in reducing their company's carbon footprint, according to car and motorcycle critic Susan Carpenter. 

At the AltCar Expo in Santa Monica last week, Ford said the future of their business extends beyond fuel-efficient vehicles.

“They’re also looking at services like car sharing. They’re understanding that with more cars on the road you have more gridlock,” Carpenter said. "How do you combat that?"

Ford has partnered with ZipCar, which allows its members to make hourly or daily car reservations of its vehicles. General Motors has partnered with Relay Ride, which allows car owners to rent out their vehicles when they aren’t using them.