Pew's Greenwald says efficiency improvements could lead to significant emission cuts

The U.S. transportation sector accounts for 27 percent of the nation's greenhouse gas emissions. What can be done to significantly lower transit and vehicle emissions? During today's OnPoint, Judi Greenwald, vice president of innovative solutions at the Pew Center on Global Climate Change, discusses a new report that lays out the greatest opportunities for emissions reductions in the transportation sector.