Charged up by electric cars

Hitting $100 oil may be just a symbolic milestone, but it certainly brings into focus a sobering reality: the price of this finite resource is more likely to go up than down. And as it goes up, so too does the exploration and development of lower-grade, dirtier oil ? so dirty, in fact, that the lifecycle greenhouse gas emissions they represent are expected to offset any gains we'll see in vehicle efficiency over the coming decade.