We reported last week that Barack Obama will regulate carbon dioxide as a pollutant under the Clean Air Act if elected. Not so for John McCain. Today writer and scientist Joseph Romm wrote on his blog Climate Progess, that a McCain-Palin administration would use a voluntary or incentive-based approach, one that “has never worked in any country to restrain emissions growth.” Today, we talk to Joe Romm about how Barack Obama and John McCain differ on their approaches to the climate crisis and alternative energy. Romm is a senior fellow at the Center for American Progress, where he maintains its blog, Climate Progress. It was named one of the top 15 green websites by Time Magazine. Romm is also the author of the 2006 book Hell and High Water: Global Warming–the Solution and the Politics–and What We Should Do. He was Acting Assistant Secretary of the U.S. Department of Energy during the Clinton Administration.