_ racts U.S.Transportation Sector Greenhouse Gas Emissions 1990-2011 &EPA United States Environmental Protection Agency Office of Transportation and Air Quality EPA-420-F-13-033 August 2013 ------- Transportation Emissions of the United States The transportation end-use sector1 is one of the largest contributors to U.S. greenhouse gas (GHG) emissions. According to the Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2011 (the Inventory), the national inventory that the U.S. prepares annually under the United Nations Framework Convention on Climate Change (UNFCCC), transportation represented 27% of total U.S. GHG emissions in 2011. Cars, trucks, commercial aircraft, and railroads, among other sources, all contribute to transportation end-use sector emissions. Within the sector, light-duty vehicles (including passenger cars and light-duty trucks) were by far the largest category, with 61% of GHG emissions, while medium- and heavy-duty trucks made up the second largest category, with 22% of emissions. Between 1990 and 2011, GHG emissions in the transportation end-use sector increased more in absolute terms than any other end-use sec- tor (industrial, agriculture, residential, commercial). Greenhouse gas emissions from transportation sources include carbon dioxide (CO,), methane (CH4), nitrous oxide (N2O), and various hydrofluorocarbons (HFCs). CO2, CH4, and N2O are all emitted via the combustion of fuels, while HFCs are the result of leaks and end-of-life disposal from air conditioners used to cool people and/or freight. Mobile Sources Transportation Highway Vehicles Aircraft Ships & Boats Rail Pipelines2 Lubricants Non-Transportation Mobile Agricultural Equipment Construction & Mining Equipment Lawn & Garden Equipment Logging Equipment Recreational Equipment When including emissions from non-transportation mobile sources3 such as agricultural, lawn and garden, and construction equipment, mobile sources constituted nearly a third, or 30%, of total U.S. GHG emissions in 2011. In addition, mobile source emissions have grown 21% since 1990 due in large part to increased demand for travel. U.S. Territories Ships and Boats 3% \ AllOther Transportation Sources Residential 17% Transportation 27% Commercial 17% 22% .1% Share of U.S. GHG Emissions by End-Use Sector* * Note: Totals may not add to 100% due to rounding. Share of U.S. Transportation End-Use Sector GHG Emissions by Source* * Note: Totals may not add to 100% due to rounding. Share of U.S. Transportation End-Use Sector GHG Emissions by Gas* * Note: Totals may not add to 100% due to rounding. End use sector emissions include (1) direct emissions and (2) emissions associated with electricity generation, as allocated to the sectors in which it is used. Includes only C02 from natural gas used to power natural gas pipelines, does not include emissions from electricity use or non-C02 gases. C02 emissions from wood biomass and biofuel consumption are not included in this document. Data can be found in the Land Use, Land-Use Change, and Forestry chapter of the Inventory. See page 4 for more information on the Inventory. 1 ------- U.S.Transportation GHG Emissions (Tg C02 Equivalent) Change from 1990 to 2011 Source 1990 1995 2000 2005 2009 2010 2011 Absolute Percent On-Road Vehicles4 Light-Duty Vehicles Passenger Cars Light-Duty Trucks Motorcycles Buses Medium- and Heavy- Duty Trucks Aircraft Commercial Aviation Military Aircraft General Aviation Ships and Boats Rail Pipelines* Lubricants Transportation Total 1,235.2 993.9 657.4 336.6 1.8 8.4 231.1 189.2 110.9 35.3 43.0 45.1 39.0 36.0 11.8 1,556.3 1,371.3 1,082.5 646.0 436.6 1.8 9.2 277.8 176.7 116.4 24.5 35.8 58.6 43.7 38.2 11.3 1,699.8 1,575.1 1,207.4 695.3 512.1 1.9 11.2 354.6 199.4 140.7 22.9 35.9 61.0 48.1 35.2 12.1 1,930.9 1,682.9 1 ,260.8 709.5 551.3 1.7 12.1 408.4 193.7 134.0 19.5 40.1 45.2 53.0 32.2 10.2 2,017.2 1,558.2 1,148.2 798.7 349.5 4.3 16.5 389.2 157.5 120.7 15.6 21.2 40.8 43.4 36.7 8.5 1 ,845.2 1,565.1 1,142.1 794.1 348.0 3.8 16.3 402.9 154.8 114.4 13.7 26.7 44.1 46.3 37.1 9.5 1,856.9 1,540.9 1,118.8 787.4 331.4 3.7 17.4 401.1 149.9 115.7 12.7 21.5 48.2 48.0 37.7 9.0 1,833.7 305.7 124.9 130.1 -5.2 1.9 9.0 169.9 -39.4 4.8 -22.6 -21.5 3.1 9.1 1.7 -2.8 277.4 24.8 12.6 19.8 -1.5 109.5 107.5 73.5 -20.8 4.3 -64.1 -50.0 6.8 23.3 4.7 -23.9 17.8 U.S. Non-Transportation Mobile GHG Emissions Change in GHG Emissions by Sector: 1990-2011 assenger Cars • Light-Duty Trucks Medium- and Heavy-Duty Trucks • Aircraft Non Transportation Mobile Sources All Other Transportation Sources * Ships and Boats Non-Transportation Mobile Agricultural Equipment Construction Equipment Other Non- Transportation Mobile Non-Transportation + Transportation Total 128.8 31.4 42.4 55.0 1,685.1 146.8 37.0 49.4 60.4 1,846.6 158.3 39.2 55.8 63.4 2,089.2 190.7 47.3 66.5 76.9 2,207.9 197.7 47.2 71.2 79.3 2,042.9 204.3 48.2 73.6 82.5 2,061.2 207.0 50.0 74.8 82.3 2,040.7 78.3 18.6 32.4 27.3 355.6 60.8 59.2 76.3 49.7 21.1 1990 1991 1993 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 3008 2009 2010 2011 U.S.Transportation GHG Emissions by Gas, 2011 (Tg C02 Equivalent) Source CO2 CH4 N20 MFCs Total Percent On-Road Vehicles Light-Duty Vehicles Passenger Cars Light-Duty Trucks Motorcycles Buses Medium- and Heavy- Duty Trucks Aircraft Commercial Aviation Military Aircraft General Aviation Ships and Boats Rail Pipelines* Lubricants Transportation Total 1,470.4 1,061.6 759.0 302.6 3.6 16.9 388.3 148.4 114.6 12.6 21.2 47.4 45.3 37.7 9.0 1,758.3 1.3 1.1 0.8 0.3 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.1 0.0 0.0 1.4 14.5 13.4 9.4 4.0 0.0 0.0 1.0 1.4 1.1 0.1 0.2 0.7 0.4 0.0 0.0 16.9 54.8 42.7 18.3 24.5 0.0 0.4 11.7 0.0 0.0 0.0 0.0 0.0 2.3 0.0 0.0 57.1 1,540.9 1,118.8 787.4 331.4 3.7 17.4 401.1 149.9 115.7 12.7 21.5 48.2 48.0 37.7 9.0 1,833.7 75.5 54.8 38.6 16.2 0.2 0.9 19.7 7.3 5.7 0.6 1.1 2.4 2.4 1.8 0.4 89.9 U.S. Non-Transportation Mobile GHG Emissions by Gas, 2011 Non-Transportation Mobile Agricultural Equipment Construction Equipment Other Non- Transportation Mobile Non-Transportation + Transportation Total 205.1 49.4 74.1 81.6 1,963.4 0.3 0.1 0.1 0.1 1.7 1.6 0.4 0.6 0.6 18.5 0.0 0.0 0.0 0.0 57.1 207.0 50.0 74.8 82.3 2,040.7 10.1 2.4 3.7 4.0 100.0 4 FHWA changed its methods for estimated vehicle miles traveled (VMT) and related data. These methodological changes included how vehicles are classified, moving from a system based on body-type to one that is based on wheelbase. These changes were first incorporated for the 2010 Inventory and apply to the 2007-11 time period. This resulted in large changes in VMT and fuel consumption data by vehicle class, thus leading to a shift in emissions among on-road vehicle classes. For instance, passenger car has been replaced by "Light duty vehicle, short WB" and other 4 axle-2 tire has been replaced by "Light duty vehicle, long WB." * CH4 and N20 emissions from pipelines are not included in transportation end-use sector totals. ------- 2011 Fuel Consumption (Billion G^o™ Energy (Tbtu) CO2 (Tg) MOTOR GASOLINE* 140.0 17,395.3 1,166.4 Transportation Light-Duty Vehicles Passenger Cars Light-Duty Trucks Medium- and Heavy-Duty Trucks Motorcycles Buses Recreational Boats 125.6 90.9 34.7 4.8 0.4 0.1 1.6 15,608.2 11,295.9 4,312.3 597.7 54.5 11.3 194.7 1 ,043.0 754.8 288.2 39.9 3.6 0.8 13.0 Non-Transportation Agricultural Equipment Construction Equipment Other Non-Transportation Mobile DIESEL FUEL" 0.8 0.6 6.1 56.0 99.3 76.3 753.3 7,767.1 7.1 5.4 53.6 574.4 Transportation Light-Duty Vehicles Passenger Cars Light-Duty Trucks Buses Medium- and Heavy-Duty Trucks Recreational Boats Ships and Boats Rail 1.7 0.4 1.3 1.5 33.9 0.4 1.0 4.0 232.9 55.6 177.4 204.3 4,702.3 49.0 144.3 554.5 17.2 4.1 13.1 15.1 347.8 3.6 10.7 41.0 Non-Transportation Agricultural Equipment Construction Equipment Other Non-Transportation Mobile RESIDUAL FUEL OIL Ships and Boats JET FUEL Commercial Aircraft General Aviation Aircraft Military Aircraft AVIATION GASOLINE General Aviation Aircraft NATURAL GAS Buses Pipelines 4.1 6.7 2.7 1.8 1.8 15.0 12.1 1.8 1.2 0.2 0.2 — — — 572.6 928.3 378.8 268.1 268.1 2,029.0 1 ,629.0 242.6 157.4 27.1 27.1 720.4 19.6 700.8 42.4 68.7 28.0 20.1 20.1 146.5 114.6 19.4 12.6 1.9 1.9 38.8 1.1 37.7 LPG Light-Duty Trucks Medium- and Heavy-Duty Trucks Buses ELECTRICITY Rail LUBRICANTS Total (Billion GVS Energy (Tbtu) CO2 (Tg) — — — — — — — 213.1 67.5 47.0 20.5 0.0 71.2 71.2 152 28,345.7 1.9 1.3 0.6 0.0 4.3 4.3 9.0 1,963.4 * Figures include ethanol blended in motor gasoline. ** Figures include biodiesel blended into diesel fuel. — Not calculated. International Bunker Fuels5 (Tg CO Equivalent) Change from 1990 to 2011 Source 1990 1995 2000 2005 2009 2010 2011 Absolute Percent Marine Residual Fuel Oil Marine Distillate Fuel Oil Aviation Jet Fuel Total 53.7 11.7 38.0 103.5 39.3 9.3 49.9 98.5 33.3 6.3 62.0 101.7 43.6 9.4 60.1 113.1 45.4 8.2 52.8 106.4 46.5 9.5 61.0 117.0 38.9 7.5 64.9 111.3 -14.8 -4.2 26.8 7.9 -27.6 -35.5 70.5 7.6 International bunker fuels are fuels used for international transport activities by commercial aircraft and ships. They are not included in Transportation or Non-Transportation Mobile Sector totals. ------- Additional Information Data Sources for This Document The source for all data in this document is the Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2011 (the Inventory) (EPA 2012). The U.S. Environmental Protection Agency prepares the national emissions inventory annually to fulfill our commitment under the United Nations Framework Convention on Climate Change (UNFCCC), using calcu- lation methods that are consistent with guidelines from the Intergovernmental Panel on Climate Change (IPCC). Complete information on this inventory is available at: www.epa.gov/climatechange/ghgemissions/usinventoryreport.html. The inventory methods and assumptions related to transportation and non-transportation mobile sources are available in the main body of the Inventory as well as Annex 3.2 of the Inventory. Definitions of Selected Transportation Categories Passenger Cars:6 Automobiles used primarily to transport less than 10 passen- gers. In 2011, passenger cars traveled a total of 2,043,409 million vehicle miles. Light-Duty Trucks:6 Pick-up trucks, sport utility vehicles (SUVs), minivans, and similar vehicles that have a gross vehicle weight rating (GVWR) of less than 8,500 pounds. GVWR is the maximum weight a vehicle is designed to carry when passengers, fuel, cargo, and any other additions to the vehicle are accounted for. In this document, light-duty vehicles with long wheelbases represent the light duty truck category. In 2011, light-duty trucks traveled a total of 603,232 million vehicle miles. Medium- and Heavy-Duty Trucks: Vehicles with a gross vehicle weight rating (GVWR) of more than 8,500 pounds. For medium- and heavy-duty trucks, GVWR is the sum of the weight of the vehicle plus the maximum weight of the cargo that the vehicle can carry. In this document, single unit trucks (with at least 2 axles and 6 tires) and combination trucks represent the medium- and heavy-duty truck category, including tractor-trailers and box trucks used for freight transportation. In addition, this category includes some vehicles that are not typically used for freight movement such as service and utility trucks. In 2011, medium- and heavy-duty trucks traveled a total of 280,990 million vehicle miles. Emissions Metrics A teragram (Tg) is equal to 1 million metric tons. Greenhouse gas (GHG) emissions are measured in this document in terms of teragrams of "carbon dioxide equivalent" (CO2 Eq); an "equivalent" refers to the Global Warming Potential (GWP) of a greenhouse gas. GWP values are determined based on the chosen time horizon and properties of the gas, such as its ability to absorb radiation and its atmospheric lifetime. CO2 has a GWP of "1"; all other greenhouse gases have GWP values relative to that of CO2. For example, methane (CH ) has a radiative forcing value7 or GWP of 21, which means that releasing one ton of CH is equivalent to releasing 21 tons of CO2. The data in this document is based on the 100-year time horizon GWP values from the Inter- governmental Panel on Climate Change's (IPCC's) Second Assessment Report, in accordance with UNFCCC reporting guidelines for national GHG inventories. More information on greenhouse gases and GWP is available at: www.epa.gov/climatechange/ghgemissions/gases.html. Pipelines: Systems that transport liquids, gases, or slurries through either above or below ground pipes. In the Inventory, the pipelines category includes emissions from the combustion of natural gas used to power pumps and other distribution equipment, while leaks and other emission sources from pipelines are assigned to the natural gas systems category. FHWA changed its methods for estimating vehicle miles traveled (VMT) and related data. These methodological changes included how vehicles are classified, moving from a system based on body-type to one that is based on wheelbase. These changes were first incorporated for the 2010 Inventory and apply to the 2007-11 time period. This resulted in large changes in VMT and fuel consumption data by vehicle class, thus leading to a shift in emissions among on-road vehicle classes. For instance, passenger car has been replaced by "Light duty vehicle, short WB" and other 4 axle-2 tire has been replaced by "Light duty vehicle, long WB." Radiative forcing is a measure of the influence a factor has in altering the balance of incoming and outgoing energy in the Earth-atmosphere system and is an index of the importance of the factor as a potential climate change mechanism (www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr.pdf). 4 ------- |