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Transportation and Climate

Measuring Greenhouse Gas Emissions from Transportation

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NOTE: You will need Adobe Acrobat Reader, available as a free download, to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.

This page provides information about measuring greenhouse gas (GHG) emissions from transportation and the contribution of transportation sources to total emissions of greenhouse gases.


GHG Emissions from a Typical Passenger Vehicle

Greenhouse Gas Emissions from a Typical Passenger Vehicle Find answers to common questions about GHG emissions from passenger vehicles and how these emissions are measured and calculated.

Fast Facts: U.S. Transportation Sector Greenhouse Gas Emissions

The Fast Facts (PDF) (5 pp, 362 K, EPA-420-F-16-020, June 2016) provides a summary overview of GHG emissions from the transportation sector from 1990-2014, as reported in the annual Inventory of U.S. Greenhouse Gas Emissions and Sinks.  Previous versions of Fast Facts are also available in the archives.

Emissions from Renewable Fuels

EPA Lifecycle Analysis of Greenhouse Gas Emissions from Renewable Fuels (PDF) (4 pp, 133K, EPA-420-F-10-006, February 2010) provides information on emissions from increased renewable fuels use, conducted as part of revisions to the Renewable Fuel Standard (RFS) program.




Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) Tool is a physics-based full vehicle simulation tool which estimates the greenhouse gas emissions for various vehicle types and powertrain technologies running over user-defined driving cycles.

Lumped Parameter Model

EPA’s Lumped Parameter Model is a desktop computer application that estimates the effectiveness of various technology combinations or “packages,” in a manner that accounts for synergies between technologies.


Learn more about how EPA uses various models to estimate GHG emissions from on-road vehicles, nonroad sources, and fuels.


Optimization Model for Reducing Emissions of Greenhouse Gases from Automobiles (OMEGA) estimates the technology cost for automobile manufacturers to achieve variable fleet-wide levels of vehicle greenhouse gas emissions.


EPA’s Greenhouse Gas Emissions Model (GEM) is a free desktop computer application that estimates the GHG emissions and fuel efficiency performance of specific aspects of heavy-duty vehicles. The model documentation provides details on how to install and use the model, and the PDF file contains the input files that were used to determine the stringency of the final Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Vehicles.


Additional Analyses

Greenhouse Gas Emissions from the U.S. Transportation Sector: 1990-2003 (PDF) (68 pp, 1.2MB, EPA420-R-06-003, March 2006) provides information to help transportation agencies, the transportation industry, researchers, and the public better understand the connection between transportation and GHG emissions in the United States. To find the most up-to-date estimates of U.S. transportation GHG emissions for any year, please see the current version of Fast Facts (PDF) (5 pp, 362 K, EPA-420-F-16-020, June 2016) or the U.S. GHG Inventory Report.

Update of Methane and Nitrous Oxide Emission Factors for On-Highway Vehicles (PDF) (39 pp, 683K, EPA420-P-04-016, November 2004) Report on Methane and Nitrous Oxide Emission Factors for use in the development of the mobile source emissions factor model MOVES.

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