Obama has moved fairly aggressively to reduce emissions of greenhouse gases, primarily through new rules on coal-fired power plants and higher fuel efficiency standards for cars.
Romney claims he would roll back some of these regulations, many of which were handed down from the Environmental Protection Agency. But as many of the rules are court-ordered, it's unclear just how successful he'd be.
"Congress would need to pass legislation that changes current regulations and laws such as the Clean Air Act," Eurasia Group analysts wrote in a recent research note. "This would be difficult even if Republicans win both the House and Senate."
Under Romney, look for a delay in or watering down of greenhouse gas regulations, but not a change in the overall direction.
