Anyone interested in addressing climate change knows we have to limit greenhouse gas emissions. The problem is, those who share that goal disagree about the best way to pursue it. The roughest head-knocking has been between the energy wonks who think we should use whatever power sources necessary to eliminate emissions—nuclear, biofuels, carbon-capture—and those who think renewable energy is the only answer. Trevor Houser, the Lab's lead from Rhodium Group, observes broad agreement on the need to dramatically expand electricity to transportation and industry, with some debates around the edges about just how much electrification is practical.