As climate change legislation moves from the House to the Senate, the transportation sector -- which contributed 28 percent of all U.S. greenhouse gas emissions in 2007, according to EPA's latest inventory -- is being called upon to provide a substantial share of the reductions needed to meet the goal of slashing carbon emissions from major U.S. sources by 80 percent (compared to 2005 levels) by 2050.
Many environmental advocates say that in addition to making vehicles more fuel-efficient and developing alternatives to carbon-based fuels, we need to reduce the number of vehicle-miles that people drive by expanding public transportation, pedestrian and bicycle networks and by adopting land use policies that reduce the need for vehicle travel and reduce the length of vehicle trips.
Can improvements in vehicle fuel efficiency and alternative fuels, combined with measures to reduce congestion and make the transportation system operate more efficiently, bring about the necessary emissions reductions? Or will we also need to pursue policies to reduce how much Americans drive? And where should the funds to pay for these policies come from?