Transportation is the largest source of carbon dioxide emissions in the U.S., mainly from vehicles and airplanes.

Transportation is the leading source of carbon dioxide emissions in the United States, contributing more to greenhouse gas emissions than any other sector. This includes emissions from cars, trucks, airplanes, and ships, all of which burn fossil fuels like gasoline and diesel. The widespread use of internal combustion engine vehicles and the continued reliance on fossil fuels for air travel significantly impact the environment. Efforts to reduce transportation-related emissions focus on increasing fuel efficiency, promoting electric vehicles, and exploring alternative fuels. Reducing emissions from this sector is crucial for meeting climate change goals and improving air quality.