The combustion of fossil fuels to move people and goods consumed 35 percent of the nation's energy in 1990 and produced over 32 percent of U.S. CO2 emissions. The expected increase in demand for transportation services over the next decade will hamper efforts to abate urban air pollution and to reduce U.S. reliance on foreign oil. Transportation will be the fastest growing source of CO2 emissions through the year 2000. The Action Plan contains a package of initiatives to curb growth in transportation sector emissions by slowing the growing demand for vehicle travel and enhancing the market for more efficient technology and cleaner fuels. (A comprehensive review of transportation options is also part of the long-term strategy described in a later section.)