_Fast racts U.S.Transportation Sector Greenhouse Gas Emissions 1990-2015 United States Environmental Protection kl flAgency Office of Transportation and Air Quality EPA-420-F-17-013 July 2017 ------- Transportation Emissions of the United States The transportation sector is one of the largest contributors to U.S. greenhouse gas (GHG) emissions. According to the Inventory of US. Greenhouse Gas Emissions and Sinks 1990-2015 (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 2015. 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 60% of GHG emissions, while medium- and heavy-duty trucks made up the second largest category, with 23% of emissions. Between 1990 and 2015, GHG emissions in the transportation sector increased more in absolute terms than any other sector (i.e. electricity generation, industry, agriculture, residential, or commercial) due in large part to increased demand for travel. Greenhouse gas emissions from transportation sources include carbon dioxide (C02), methane (CH4), nitrous oxide (N20), and various hydrofluorocarbons (HFCs). C02, CH4, and N20 are all emitted via the combustion of fuels, while HFC emissions are the result of leaks and end-of- life disposal from air conditioners used to cool people and/or freight.2 Mobile Sources Transportation Non-Transportation Mobile Highway Vehicles Agricultural Equipment Aircraft Construction & Mining Equipment Ships & Boats Lawn & Garden Equipment Rail Logging Equipment Lubricants Recreational Equipment Pipelines1 When including emissions from non-ttansportation mobile sources such as agricultural, lawn and garden, and construction equipment, mobile sources constituted 31% of total U.S. GHG emissions in 2015. Medium- and Heavy-Duty Trucks 23% Electricity 29% Transportation 27% Share of U.S. Transportation Sector GHG Emissions by Gas, 20154 Note: Totals may not add to 100% due to rounding. Light-Duty Vehicles Share of U.S. Transportation Sector GHG Emissions by Source, 20154'5 Note: Totals may not add to 100% due to rounding. Other 4% Rail 2% Residential 6% Commercial Note: Totals may not add to 100% due to rounding. Ships & Boats 2%v Aircraft 9% Share of U.S. GHG Emissions by Sector, 20153'4 1 Pipeline emissions in the transportation sector include only C02 from the combustion of natural gas at compressor stations that power natural gas pipelines, not emissions from electricity use, non-C02 gases, or other types of pipeline equipment. Note that natural gas pipe- line compressor stations are stationary equipment that are included in the transportation sector, but are not considered mobile sources. 2 C02 emissions from the combustion of biofuels are not directly included in the energy sector contribution (which includes the contribution of transportation and non-transportation mobile sources) to U.S. totals in the Inventory; instead, net carbon fluxes from changes in biogenic carbon reservoirs are accounted in the estimates for Land Use, Land-Use Change, and Forestry in the Inventory. See page 4 for more information on the Inventory. 3 For presentation purposes, emissions from territories which constitute less than 1% of the total U.S. GHG emissions, are not shown in this chart although they are included in the total emissions used to calculate the percentage share of emissions from each sector. See Table ES-6 in the Executive Summary of the Inventory for official data. See page 4 for more information on the Inventory. 4 "Transportation" emissions in these pie charts include C02, N20, CH4, and HFCs from transportation sources like highway vehicles, aircraft, ships and boats, rail, pipelines and lubricants. They do not include emissions from non-transportation mobile sources such as agriculture and construction equipment. 5 "Other" sources include buses, motorcycles, pipelines, and lubricants. ------- U.S.Transportation GHG Emissions (Tg C02 Equivalent) Change from 1990 to 2015s Source 1990 1995 2000 2005 2010 2014 20156 Absolute Percent On-Road Vehicles6,7 1,233.5 1,370.4 1,572.6 1,673.4 1,541.3 1,553.8 1,522.0 288.5 23.4 Light-Duty Vehicles 991.9 1,083.1 1,212.1 1,260.9 1,132.0 1,122.1 1,083.5 91.7 9.2 Passenger Cars 656.7 646.6 697.2 708.7 783.4 778.4 758.4 101.8 15.5 Light-Duty Trucks 335.2 436.5 514.9 552.2 348.7 343.7 325.1 -10.1 -3.0 Motorcycles 1.8 1.8 1.9 1.7 3.7 3.9 3.7 2.0 110.2 Buses 8.5 9.2 11.0 12.0 15.9 19.5 19.8 11.3 134.0 Medium- and Heavy- Duty Trucks 231.4 276.2 347.7 398.9 389.7 408.3 415.0 183.6 79.3 Aircraft 189.2 176.7 199.4 193.6 154.8 151.5 160.7 -28.5 -15.1 Commercial Aviation 110.9 116.3 140.6 134.0 114.4 116.3 120.1 9.2 8.3 Military Aircraft 35.3 24.5 22.9 19.5 13.7 15.5 14.9 -20.5 -57.9 General Aviation 42.9 35.8 35.9 40.1 26.7 19.7 25.7 -17.2 -40.1 Ships and Boats 44.9 58.5 61.3 45.0 44.9 17.6 33.1 -11.8 -26.4 Rail 35.8 40.0 42.7 46.4 40.2 44.4 42.9 7.1 19.8 Pipelines8 36.0 38.4 35.4 32.4 37.3 39.4 38.0 1.9 5.4 Lubricants 11.8 11.3 12.1 10.2 9.5 9.1 10.0 -1.9 -15.8 Transportation Total 1,551.2 1,695.2 1,923.5 2,001.0 1,827.9 1,815.8 1,806.6 255.4 16.5 U.S. Non-Transportation Mobile GHG Emissions Non-Transportation Mobile6,9 128.8 146.7 159.5 191.8 203.1 213.9 208.1 79.3 61.6 Agricultural Equipment 31.4 37.0 39.7 47.9 48.4 51.3 48.0 16.6 52.9 Construction Equipment 42.4 49.3 56.6 67.4 74.0 80.4 78.8 36.4 85.9 Other Non- Transportation Mobile 55.0 60.4 63.2 76.5 80.7 82.2 81.3 26.3 47.8 Non-Transportation + Transportation Total 1,680.0 1,841.9 2,083.0 2,192.8 2,031.0 2,029.7 2,014.7 334.7 19.9 U.S.Transportation GHG Emissions by Gas, 2015 (Tg C02 Equivalent) Source o o ch4 n2o HFCs Total Percent On-Road Vehicles7 1,467.0 1.5 11.2 42.3 1,522.0 75.5 Light-Duty Vehicles 1,033.7 1.3 10.3 38.3 1,083.5 53.8 Passenger Cars 735.7 1.0 6.9 14.9 758.4 37.6 Light-Duty Trucks 298.0 0.3 3.4 23.4 325.1 16.1 Motorcycles 3.7 0.0 0.0 0.0 3.7 0.2 Buses 19.3 0.0 0.1 0.4 19.8 1.0 Medium- and Heavy- Duty Trucks 410.4 0.1 0.8 3.6 415.0 20.6 Aircraft 159.2 0.0 1.5 0.0 160.7 8.0 Commercial Aviation 119.0 0.0 1.1 0.0 120.1 6.0 Military Aircraft 14.7 0.0 0.1 0.0 14.9 0.7 General Aviation 25.5 0.0 0.2 0.0 25.7 1.3 Ships and Boats 32.3 0.0 0.6 0.1 33.1 1.6 Rail 39.9 0.1 0.3 2.7 42.9 2.1 Pipelines8 38.0 0.0 0.0 0.0 38.0 1.9 Lubricants 10.0 0.0 0.0 0.0 10.0 0.5 Transportation Total 1,746.3 1.6 13.6 45.1 1,806.6 89.7 Rail Electricity 3.72 0.00 0.04 0.00 3.76 NA U.S. Non-Transportation Mobile GHG Emissions by Gas, 2015 Change in GHG Emissions by Sector: 1990-2015 ¦ Light- Duty Vehicles ¦ Medium- and Heavy-Duty Trucks ¦Aircraft ¦ Rail ¦ Non Transportation Mobile Sources ¦ All Other Transportation Sources ¦ Ships and Boats Non-Transportation Mobile9 206.1 0.4 1.6 0.0 208.1 10.3 Agricultural Equipment 47.5 0.2 0.4 0.0 48.0 2.4 Construction Equipment 78.1 0.1 0.6 0.0 78.8 3.9 Other Non- Transportation Mobile 80.6 0.1 0.6 0.0 81.3 4.0 Non-Transportation + Transportation Total 1,952.5 2.0 15.1 45.1 2,014.7 100.0 1990 1991 1992 1994 1995 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 The methodology for estimating the share of gasoline used in on-road and non-road applications was updated in 2016, resulting in a break in the time series between 2015 and previous years. See page 4 for more details. GHG emissions and vehicle miles traveled (VMT) estimates for on-road vehicles presented in the Inventory are based on FHWA data. FHWA changed its methods for estimating (VMT) and related data in 2011. 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— 14 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 vehicles short WB" and "other 2-axle 4-tire vehicles" has been replaced by "light-duty vehicles long WB." Includes only C02 from natural gas used to power natural gas pipelines, does not include emissions from electricity use or non-C02 gases. Note: non-transportation C02 emissions estimates are presented here and in Annex 3.2 of the Inventory for informational purposes, but these emissions are officially accounted for in other energy sectors in the Inventory (i.e., industrial, residential, commercial sectors) using a different method. See Annex 3.2, Supplemental Inform^n on Transportation-Related GHG Emissions, of the Inventory for more information. ------- 2015 Fuel Consumption Volume (billion gallons unless otherwise specified) Energy (Tbtu) C02 (Tg) MOTOR GASOLINE 127.1 15,779.0 1,125.5 Transportation10 Light-Duty Vehicles 114.4 14,220.9 1,014.5 Passenger Cars 82.4 10,251.0 731.3 Light-Duty Trucks 31.9 3,969.9 283.2 Medium- and Heavy-Duty Trucks 4.4 550.6 39.3 Motorcycles 0.4 51.3 3.7 Buses 0.1 12.5 0.9 Recreational Boats 1.4 170.4 12.2 Non-Transportation" Agricultural Equipment 0.2 19.1 1.4 Construction Equipment 0.4 44.3 3.2 Other Non-Transportation Mobile 5.9 710.0 50.5 DISTILLATE FUEL 60.2 8,272.7 611.8 Transportation10 Light-Duty Vehicles 1.8 246.4 18.2 Passenger Cars 0.4 58.1 4.3 Light-Duty Trucks 1.4 188.3 13.9 Buses 1.7 234.0 17.3 Medium- and Heavy-Duty Trucks 36.3 4,994.4 369.4 Recreational Boats 0.4 52.8 3.9 Ships and Boats 1.2 162.7 12.0 Rail 3.9 539.1 39.9 Non-Transportation11 Agricultural Equipment 4.5 623.2 46.1 Construction Equipment 7.4 1,013.2 74.9 Other Non-Transportation Mobile 3.0 406.9 30.1 RESIDUAL FUEL OIL 0.4 56.6 4.2 Ships and Boats 0.4 56.6 4.2 JET FUEL 16.2 2,183.8 157.7 Commercial Aircraft 12.5 1,692.1 119.0 General Aviation Aircraft 2.3 304.8 24.0 Military Aircraft 1.4 186.9 14.7 Volume (billion gallons unless otherwise specified) Energy (Tbtu) C02 (Tg) AVIATION GASOLINE 0.2 21.1 1.5 General Aviation Aircraft 0.2 21.1 1.5 NATURAL GAS (million cubic feet) 705,593.1 731.7 38.8 Passenger Cars 68.5 0.1 0.0 Light-Duty Trucks 218.1 0.2 0.0 Medium- and Heavy-Duty Trucks 517.9 0.5 0.0 Buses 13,925.9 14.4 0.8 Pipelines 690,862.5 716.4 38.0 LPG 0.6 48.3 3.0 Passenger Cars 0.0 1.1 0.1 Light-Duty Trucks 0.2 14.2 0.9 Medium- and Heavy-Duty Trucks 0.3 28.0 1.7 Buses 0.1 5.1 0.3 LUBRICANTS 1.0 148.1 10.0 Total12 211.7 27,241.4 1,952.5 BIOFUELS Transportation BiodieseP3 1.5 190.6 14.1 EthanoP 13.1 1,109.4 75.9 10 Fuel consumption, energy, and C02 emissions from transportation sources using motor gasoline and distillate fuel exclude contributions from biofuels. 11 Non-transportation mobile fuel consumption, energy, and C02 are estimated based on the N ON ROAD component of EPA's MOVES model (see www.epa.gov/moves/nonroad-model-nonroad-engines-equipment-and-vehicles). Because the fuel compo- sition in the NONROAD model is intended to reflect real-world usage, these estimates may include low-level ethanol blends. Note that these estimates are presented here and in Annex 3.2 of the Inventory for informational purposes, but that non- transportation mobile source C02 emissions are officially accounted for in other energy sectors in the Inventory (e.g., the industrial sector) using a different method and do not include emissions from biofuels. 12 Total Volume is the sum of physical (billion) gallons of fuel; because natural gas volumes are reported as million cubic feet, natural gas volumes are converted to billion gallons of gasoline equivalent for the Total Volume (billion gallons) sum in this table. 13 Biofuels are presented as line items below the total for informational purposes only, in line with IPCC methodological guidance and UNFCCC reporting obligations. Biofuel estimates only reflect transportation sources and do not include biofuels used in non-transportation mobile sources, e.g., ethanol used in commercial or industrial applications. C02 emissions from the combustion of biofuels are not directly included in the energy sector contribution (which includes the contribution of transpor- tation sources) to U.S. totals in the Inventory; instead, net carbon fluxes from changes in biogenic carbon reservoirs are accounted in the estimates for Land Use, Land-Use Change, and Forestry in the Inventory. See page 4 for more information on the Inventory. 3 ------- Additional Information Data Sources for This Document The source for all data in this document is the Inventory of US. Greenhouse Gas Emissions and Sinks 1990-2015 (the Inventory) (EPA 2017). The U.S. Environmental Protection Agency prepares the inventory annually to fulfill the U.S. commitment under the United Nations Framework Convention on Climate Change (UNFCCC), using calculation methods that are consistent with guidelines from the Intergovernmental Panel on Climate Change (IPCC). Complete information on the inventory is available at: www.epa.gov/ghgemissions/ inventory-us-greenhouse-gas-emissions-and-sinks. 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. Inventory Definitions of Selected Transportation Categories14 Light-Duty Vehicles: passenger cars and light-duty trucks Passenger Cars:15 automobiles used primarily to transport 12 people or less. In 2015, passenger cars traveled a total of 2,147,840 million vehicle miles. Light-Duty Trucks:15 vehicles used primarily for transporting light-weight cargo or which are equipped with special features such as four-wheel drive for off-road operation. In the U.S., this category also includes many vehicles that primarily transport passengers such as sport utility vehicles (SUVs) and minivans. The gross vehicle weight rating (GVWR) normally ranges around 8,500 pounds or less. 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 2015, light-duty trucks traveled a total of 631,852 million vehicle miles. Medium- and Heavy-Duty Trucks:15 vehicles with GVWR of more than around 8,500 pounds. In the Inventory, single unit trucks 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 2015, medium- and heavy-duty trucks traveled a total of 296,073 million vehicle miles. 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. 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" (C02 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. C02 has a GWP of "1"; all other greenhouse gases have GWP values relative to that of COr For example, methane (CH4) has a radiative forcing value or GWP of 25, which means that releasing one ton of CH4 is equivalent to releasing 25 tons of C02. 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) Fourth Assessment Report16, in accordance with UNFCCC reporting guidelines for national GHG inventories. More information on greenhouse gases and GWP is available at: www.epa.gov/ghgemissions/overview-greenhouse-gases. Gasoline Method Update for 2015 In 2016, the Federal Highway Administration (FHWA) updated its methods for estimating the share of gasoline used in on-road and non-road applications. While these methodology updates did not impact total U.S. gasoline consumption estimates in the Inventory, they did create a time-series inconsistency between 2015 and previous years in gasoline consumption estimates for transportation, as well as agricultural, construction, commercial, and industrial non-transportation mobile sources. The method updates are discussed further in the Planned Improvements sections of Chapter 3.1 of the Inventory under C02 from Fossil Fuel Combus- tion and CH4 and N20 from Mobile Combustion. 14 The data used to estimate emissions for specific transportation categories may not directly align with the Inventory's definition of the categories; both the data and Inventory definitions may also differ from EPA's regulatory definitions for the same categories. 15 GHG emissions and vehicle miles traveled (VMT) estimates for on-road vehicles presented in the Inventory are based on FHWA data. FHWA changed its methods for estimating (VMT) and related data in 2011. 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— 15 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 vehicles short WB" and "other 2-axle 4-tire vehicles" has been replaced by "light duty vehicles long WB." 16 See www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr.pdf. 4 ------- |