Graphs shows percentage of Americans that live in regions where powering an electric vehicle on the regional electricity grid produces lower global warming emissions than a gasoline car expressed in terms of combined cith/highway fuel economy rating of that car (a gasoline-powered car that would have global warming emissions equivalent to driving an EV). Graphs show change from 2009 to 2012 as the electric grid gets cleaner. Source: Union of Concerned Scientist, cleaner Cars from Cradle to Grave, based on data on Figure 5, pp. 14