But pollution from cars and trucks has proved much trickier for states to take on. Transportation now accounts for one-third of America’s carbon-dioxide emissions, surpassing power plants as the largest source, and vehicle emissions have been steadily rising over the past few years. Federal fuel-economy standards were widely seen as a vital tool for curbing gasoline use.
“We’ve seen nowhere near the same progress in transportation as we’ve seen in electricity,” said Jordan Stutt, a policy analyst at the Acadia Center, a group in New England that is pushing for cleaner energy.
Read the full article from the New York Times here.