Car Emissions and Global Warming

Published Jul 18, 2014 Updated Aug 20, 2025

Cars in traffic sitting in a cloud of exhaust smoke.
iStockphoto.com/ssuaphoto

Global warming endangers our health, jeopardizes our national security, and threatens other basic human needs. Some impacts—such as record high temperatures, rising seas, and severe flooding and droughts—are already increasingly common.

Our personal vehicles are a major cause of global warming. Collectively, cars and trucks account for nearly one-fifth of all US emissions, emitting over 23 pounds of carbon dioxide and other global-warming gases for every gallon of gas. Over four pounds comes from the extraction, production, and delivery of the fuel, while the great bulk of heat-trapping emissions—about 19 pounds per gallon—comes right out of a car’s tailpipe.

In total, the US transportation sector—which includes cars, trucks, planes, trains, ships, and freight—produces nearly thirty percent of all US global warming emissions, more than almost any other sector.

Two cars charging at a public parking lot of a park in the city of Cambridge, MA
Two cars charging at a public parking lot of a park in the city of Cambridge, MA
UCS/C. Ward-de León

Solutions are here

Fuel-efficient vehicles use less gas to travel the same distance as their less efficient counterparts. When we burn less fuel, we generate fewer emissions. When emissions go down, the pace of global warming slows.

Cleaner fuels have lower pollution impacts than existing gasoline and diesel when considering the emissions from both the production of those fuels and their use. Well-designed performance standards for transportation fuel can reduce emissions from fuel production and use and accelerate transportation electrification.

Electric cars and trucks use electricity as fuel, producing fewer emissions than their conventional counterparts. When the electricity comes from renewable sources, all-electric vehicles produce zero emissions to drive.

These and other solutions are here today—but more can be done. Learn more about our plan to Transform Transportation.

Related resources