Transportation Research Program for Mitigating and Adapting to Climate Change and Conserving Energy. Special Report 299

摘要

The risks posed by climate change and the dependence on imported petroleum are among the most challenging problems facing the United States. Many state and national policy makers are embracing proposals to reduce total greenhouse gas (GHG) emissions by 50 to 80 percent below current levels by 2050 and to reduce energy consumption by the transportation sector. Transportation, which depends on petroleum for 97 percent of its fuel, is a major contributor to both climate change and energy dependence. It accounts for 28 percent of U.S. GHG emissions and consumes twice as much petroleum as the United States produces annually. Passenger and freight vehicles using surface transportation modes account for about 88 percent of transportation carbon dioxide emissions and for a comparable share of energy consumption.