Carbon Pollution from Transportation | US EPA (2024)

On this page:

• Transportation and climate change
• EPA programs to reduce carbon pollution

Transportation and Climate Change

Burning fossil fuels like gasoline and diesel releases carbon dioxide, a greenhouse gas, into the atmosphere. The buildup of carbon dioxide (CO₂) and other greenhouse gases like methane (CH₄), nitrous oxide (N₂O), and hydrofluorocarbons (HFCs) is causing the Earth’s atmosphere to warm, resulting in changes to the climate we are already starting to see today.

​Greenhouse gas (GHG) emissions from transportation account for about 28 percent of total U.S. greenhouse gas emissions, making it the largest contributor of U.S. GHG emissions. Between 1990 and 2022, GHG emissions in the transportation sector increased more in absolute terms than any other sector.

Learn more:

• Global emissions by economic sector
• Fast facts on transportation greenhouse gas emissions

EPA Programs to Reduce Carbon Pollution from Transportation

EPA is addressing climate change by taking the following actionsto reduce GHG emissions from the transportation sector. Many of these programs havebenefits beyond cutting carbon. For example, decreasing fuel consumption can reduce our dependence on foreign oil and save consumers money at the pump.

Setting GHG Emissions Standards for Cars and Trucks

EPA and DOT issued a joint rule-making that set GHG emissions and fuel economy standards for the largest sources of greenhouse gases from transportation, including cars, light trucks, and heavy-duty trucks.

Light-duty GHG regulations for passenger vehicles and trucks are projected to:

• Cut 6 billion metric tons of GHG emissions over the lifetimes of the vehicles sold in model years 2012-2025 and allowing manufacturers flexibility in meeting the standards;
• Nearly double the fuel efficiency while protecting consumer choice; and
• Reduce America’s dependence on oil and provide significant savings for consumers at the pump.

Heavy-duty GHG regulations are projected to:

• Reduce CO₂ emissions by about 270 million metric tons over the life of vehicles built under the program, saving about 530 million barrels of oil; and
• The proposed “Phase 2” program includes standards that would further reduce GHG emissions and improve the fuel efficiency of medium and heavy-duty trucks.

Learn more:

• The Automotive Trends Report (formerly the Manufacturer Performance Report)
• Analyses and reports for setting GHG emissions standards for cars and trucks

Increasing the Use of Renewable Fuels

Congress created the Renewable Fuel Standardprogram in an effort to reduce greenhouse gasemissions and expand the nation’s renewable fuels sector while reducing reliance on imported oil. Renewable fuels are produced fromplants, crops and otherbiomass, andcan reduce greenhouse gas emissions when compared to burning the fossil fuels they replace.

• Renewable Fuel Standard Program

Taking First Steps to Set aGreenhouse Gas Standards for Aircraft

EPA along with the Federal Aviation Agency at the United Nations' International Civil Aviation Organization have developed international carbon dioxide emissions standards for aircraft. EPA is also now working through the process of potentially setting domestic regulations under the Clean Air Act that address GHG emissions from certain classes of engines used in aircraft.

Learn more:

• Regulations for GHG emissions from aircraft

Greening the Federal Fleet

The 2007 Energy Independence and Security Actrequires federal agencies to only acquire cars, light trucks, or medium-duty passenger vehicles that are low greenhouse gas emitting. Each year, EPA evaluates the greenhouse gas emissions performance of the fleet to determinewhich vehicles in each class emit less harmful greenhouse gases. The law requires federal agencies to purchase these high performing vehicles. Over time this will result in a greener federal fleet.

Learn more:

• Federal fleets

Reducing Greenhouse Gas Emissions Associated with Moving Goods

SmartWayhelps the freight transportation sector improve supply chain efficiency, reducing greenhouse gases and saving fuel costs for companies who participate. Through SmartWay, EPA and its partners are making significant gains in the efficiency of how our nation moves goods, helping address air quality challenges, improvingpublic health and reducingfreight’s contribution to climate change.

Learn more:

• SmartWay

Informing Consumers Information on Fuel Economy and Advanced Technology Cars

Since the mid-1970s EPA has required automakers to display a label on new cars and light trucks with information on vehicles' fuel economy and fuel costs. Labels on today's cars also include ratings on greenhouse gas and smog-forming pollutants.EPA provides online resources, such as the Green Vehicle Guide and the joint EPA-DOE websitefueleconomy.gov, tohelp consumers identify vehicles that can save them money at the pump and reduce their transportation-related emissions.

EPA’s SmartWay light duty program goes furtherand identifiesthetop performing vehicles in terms offuel economy and emissionsto assist consumers in making an environmentally friendly purchase.

Learn more:

• Green Vehicle Guide
• Fueleconomy.gov
• Consider a SmartWay vehicle