Last reviewed on 12-01-2023

Documentation of California's Greenhouse Gas Inventory (2023 Edition - Last updated on 12-1-2023)

♦ Category: Energy

IPCC: 1A3biii - Fuel Combustion Activities - Transport - Road Transportation - Heavy-duty Trucks and Buses
Sector: Transportation : On Road : Heavy-duty Vehicles : Heavy-duty Trucks

♦ Activity: Fuel combustion - Ethanol

♦ Greenhouse gas: Methane ( CH4 )

► Year 2006 —

● Greenhouse gas emission estimate —

Amount: 46.97 tonnes of CH4 Emitted (1,174 tonnes CO2 Eq.)
Basis: Calculation
Calculation: [EMFAC CH4 emission] * ([Fuel sales] / [EMFAC total fuel combustion]) * [Fraction of fuel mix]
Reference: CARB (2016). Technical support document on GHG inventory methodologies for the 2000-2014 inventory. See Discussion of emissions from on-road transportation available at: https://ww3.arb.ca.gov/cc/inventory/pubs/reports/2000_2014/ghg_inventory_00-14_technical_support_document.pdf

● Activity level used in calculations —

Activity: Fuel combustion = 71,407,232 gal of Ethanol
Basis: Calculation
Calculation: [EMFAC category fuel combustion] * ([Fuel sales] / [EMFAC total fuel combustion]) * [Fraction of fuel mix]
Reference: CARB (2016). Technical support document on GHG inventory methodologies for the 2000-2014 inventory. See Discussion of emissions from on-road transportation available at: https://ww3.arb.ca.gov/cc/inventory/pubs/reports/2000_2014/ghg_inventory_00-14_technical_support_document.pdf
Reference: Not Applicable.

● Parameters and Constants used in calculations —

Parameter: EMFAC category fuel combustion = 1,214,612,744 gal
Reference: CARB (2021). The California Air Resources Board's Emission FACtors (EMFAC) model was used to calculate emission rates from all motor vehicles, such as passenger cars and heavy-duty trucks, operating on highways, freeways, and local roads in California. http://www.arb.ca.gov/msei/msei.htm
Parameter: EMFAC CH4 emission = 799,014,096 g (i.e. 799.01 tonnes)
Reference: CARB (2021). The California Air Resources Board's Emission FACtors (EMFAC) model was used to calculate emission rates from all motor vehicles, such as passenger cars and heavy-duty trucks, operating on highways, freeways, and local roads in California. http://www.arb.ca.gov/msei/msei.htm
Parameter: EMFAC N2O emission = 629,764,558 g (i.e. 629.76 tonnes)
Reference: CARB (2021). The California Air Resources Board's Emission FACtors (EMFAC) model was used to calculate emission rates from all motor vehicles, such as passenger cars and heavy-duty trucks, operating on highways, freeways, and local roads in California. http://www.arb.ca.gov/msei/msei.htm
Parameter: EMFAC total fuel combustion = 15,347,917,816 gal
Reference: CARB (2021). The California Air Resources Board's Emission FACtors (EMFAC) model was used to calculate emission rates from all motor vehicles, such as passenger cars and heavy-duty trucks, operating on highways, freeways, and local roads in California. http://www.arb.ca.gov/msei/msei.htm
Parameter: Fraction of fuel mix = 0.0571
Reference: CARB (2016). Technical support document on GHG inventory methodologies for the 2000-2014 inventory. See Discussion of emissions from on-road transportation available at: https://ww3.arb.ca.gov/cc/inventory/pubs/reports/2000_2014/ghg_inventory_00-14_technical_support_document.pdf
Parameter: Fuel sales = 15,802,491,301 gal
Reference: CDTFA (2022). [Formerly referred to as Board of Equalization (BOE)]. California Department of Tax and Fee Administration. Fuel Taxes Statistics & Reports - Motor Vehicle Fuel. Accessed online at: https://www.cdtfa.ca.gov/taxes-and-fees/spftrpts.htm
Constant: Global warming potential of CH4 = 25
Reference: IPCC (2007). Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Solomon S., Qin D., Manning M., Chen Z., Marquis M., Averyt K.B., Tignor M., and Miller H.L. (eds.). http://www.ipcc.ch/publications_and_data/publications_ipcc_fourth_assessment_report_synthesis_report.htm

● Greenhouse gas emitted per unit activity (derived from values listed above) —

Amount: 0.658 g of CH4 per gal of Ethanol
16.4 g of CO2eq. per gal of Ethanol