Energy efficiency is a proven resource with significant potential to dramatically reduce power plant emissions and to do so at low cost. Power plants represent 40 percent of the nation's total climate-changing pollution. NRDC's innovative proposal to slash this pollution, Closing the Power Plant Carbon Pollution Loophole, illustrates this potential. Meanwhile, more than half of U.S. states have already made commitments to achieving aggressive levels of energy savings, and several have demonstrated it is possible to quickly ramp up the infrastructure necessary to cut carbon pollution on a large scale. This issue brief discusses how the possibilities for reductions in electricity consumption are huge and available everywhere, and that stringent building codes and appliance standards, combined with regulatory reform addressing investment barriers, can help the United States dramatically expand energy efficiency now to combat climate change, save money, create jobs, and clean the air we breathe.