Climate Change and Transportation

What’s the Problem?

Transportation is one of the largest sources of greenhouse gas (GHG) emissions in the United States, and personal motor vehicle travel is responsible for the majority of transportation emissions. These vehicles include passenger cars, sport utility vehicles, pickup trucks, minivans, and motorcycles.

GHGs contribute to climate change by trapping heat in the atmosphere, causing the earth’s temperature to increase. By reducing the number of vehicle miles traveled, easing congestion and supporting more efficient land use patterns, we can make transportation more energy efficient, reduce GHG emissions, and help slow the rate of climate change.

Who’s at Risk?

Carbon dioxide (CO₂), the primary greenhouse gas produced by the transportation sector, mixes and disperses very effectively through the atmosphere, meaning it doesn’t tend to concentrate in any particular area for long, but it can remain in the atmosphere for up to 200 years. Since CO₂ mixes globally, even locally produced CO₂ emissions contribute to the increase in global concentrations of GHGs, and elevate the risk of harmful climate change impacts for people worldwide.

Can It Be Prevented?

To reduce atmospheric concentrations of GHGs and hold off the most severe impacts of climate change, the global community, especially large-scale emitters of GHGs, will have to substantially reduce their emissions. At the rate GHG emissions are occurring in the United States, reducing transportation emissions is a necessary component of any strategy to address climate change. However, reducing GHG emissions from transportation is not without challenges. The U.S. has one of the largest transportation systems in the world, and transportation is embedded into almost every part of our lives and our economy.

People can’t be asked to drive less without other options. We choose our travel mode based on things like availability, speed, convenience, and safety. As use increases, many public transportation systems run beyond their capacity, struggling to maintain their quality and reliability.

The Bottom Line

There are many ways to decrease transportation-related GHG emissions.

Driving Alternatives

Skip driving a couple times per week, consider alternatives like walking or biking, and consider telecommuting or carpooling.

Public Transportation

Using public transportation is one of the best ways to reduce GHG emissions. Public transportation produces fewer GHGs per mile than private vehicles. By using public transportation, we also reduce travel by private vehicles.

Smart Growth

How we invest in our transportation infrastructure matters. People drive less in neighborhoods that are more walkable and offer more transportation choices. Smart growth means using land development techniques that help cut the amount of vehicle travel required to meet the needs of the people who live, work, shop and play in the community. This means building new developments in existing urban areas with available transit services or where more services are within walking or bicycling distance.

Case Example

A building developer wants to design a unique community that supports smart growth and that doesn’t require the use of a car for every trip. He designs the community based on a grid of streets, sidewalks and pathways that encourage walking and bicycling. He locates office buildings, shops and public transportation within walking or biking distance of most homes. He also plans to build an elementary school in the community so children can walk to school instead of taking buses. The design of the streets and houses encourage walking; streets are narrow to slow traffic and make crossing easier. By making options like walking, biking and public transportation more accessible, the developer is enabling the community’s residents to choose less fuel intensive forms of transportation, and helping them to reduce their GHG emissions.