Editor's Summary

The U.S. energy system achieved mixed success in its quest toward sustainability from 2000-2006. On one hand, carbon emissions as a fraction of GDP declined, end-use efficiency increased, and energy-related air quality improved. On the other hand, high levels of fossil fuel combustion continued, and U.S. energy use and emissions relative to other industrialized nations remained high. To continue successes while combating deficiencies, the federal government should increase energy efficiency through applied standards and improved technology, support research and development of energy-efficient commercial buildings, implement a tax or cap-and-trade system, support biofuel research, and set emissions targets for industry.