The majority of U.S. greenhouse gas (GHG) emissions—84 percent—are in the form of carbon dioxide (CO₂), resulting almost entirely from the combustion of fossil fuels. As a result, energy policies that reduce fossil fuel use will reduce GHG emissions. Fossil fuel use can be reduced by: (1) deploying technologies that increase energy efficiency (e.g., more efficient power plants, cars, and appliances) and (2) employing non-fossil fueled energy sources (e.g., solar, wind, geothermal, biomass, hydroelectric, nuclear energy, or renewables-based hydrogen). CO₂ emissions also can be reduced by shifting from high-carbon to lower-carbon fuels (e.g., shifting from coal to natural gas in the electricity sector), and by employing carbon capture and sequestration technologies.

A “climate-friendly” energy policy can advance climate objectives while serving energy policy goals. However, a climate-friendly energy policy is not a substitute for climate policy. More significant GHG emissions reductions would be necessary in order to address climate change than can be justified solely on the basis of traditional energy policy objectives. The energy policy options outlined in this brief represent sensible and important first steps in U.S. efforts to reduce GHG emissions.