Motor vehicles are responsible for almost a quarter of annual US emissions of carbon dioxide (CO2), the primary global-warming gas. The US transportation sector emits more CO2 than all but three other countries' emissions from all sources combined. And motor vehicle emissions will continue to increase as more vehicles hit America's roads and the number of miles driven grows.
Three factors contribute to CO2 emissions from cars and trucks:
- Amount of fuel used
- Amount of CO2 released when a particular fuel is consumed
- Number of vehicle miles traveled
Increase Fuel Efficiency
The amount of fuel consumed by motor vehicles governs how much CO2 pollution enters the atmosphere: the more gasoline burned, the more CO2 released. Automobiles need to become more fuel efficient. For the last decade, however, the fuel-economy standards for motor vehicles have stagnated. In addition, low gas prices have helped create a market for gas-guzzling light trucks such as sport-utility vehicles (SUVs) and minivans, which have actually led to an increase in CO2 emissions.
Increasing fuel efficiency is a cost-effective and technologically feasible method to address the threat of global warming, benefit our economy, and protect public health. To do this, government policies must:
- Strengthen fuel-efficiency standards (CAFE) for all passenger vehicles and eliminate the light-truck (SUV) loophole.
- Support the development and marketing of advanced vehicles,
like battery electrics, hybrid electrics, and fuel cells.
