Cars in the US are responsible for nearly half the greenhouse gases emitted by vehicles around the world, and scientists say reducing emissions is crucial to combating global warming.<br /><br />Carmakers are rushing to release the first fully-electric vehicles, and the US city of San Francisco is preparing for drivers to plug in instead of fill up, at special stations set up for fully-electric cars.<br /><br />Al Jazeera's Mike Kirsch reports. (Apr 10, 2010)
