Last reviewed on November 2, 2011 at 10:05

Documentation of California's Greenhouse Gas Inventory (First Edition - Last updated on 11/19/2007)

♦ Category: Energy

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

♦ Activity: Fuel combustion - Gasoline

♦ Greenhouse gas: Carbon dioxide ( CO2 )

► Year 1990 —

● Greenhouse gas emission estimate —

Amount: 10,582,161 tonnes of CO2 Emitted (10,582,161 tonnes CO2 Eq.)
Basis: Calculation
Calculation: ([EMFAC CO2 emission] + ([EMFAC CO emission] * [Molecular weight ratio of CO2 to CO]) + ([EMFAC THC emission] * [Molecular weight ratio of CO2 to CH2])) * ([FHWA fuel sales] / [EMFAC total fuel combustion])
Reference: ARB (2009). Technical Support Document for California’s Greenhouse Gas Emissions Inventory and 1990 Emissions Level. California Air Resources Board. (March 2009). Available online at: /cc/inventory/doc/methods_v1/ghg_inventory_technical_support_document.pdf

● Activity level used in calculations —

Activity: Fuel combustion = 1,193,893,604 gal of Gasoline
Basis: Calculation
Calculation: [EMFAC category fuel combustion] * ([FHWA fuel sales] / [EMFAC total fuel combustion])
Reference: ARB (2009). Technical Support Document for California’s Greenhouse Gas Emissions Inventory and 1990 Emissions Level. California Air Resources Board. (March 2009). Available online at: /cc/inventory/doc/methods_v1/ghg_inventory_technical_support_document.pdf

● Parameters and Constants used in calculations —

Parameter: EMFAC category fuel combustion = 1,288,560,257 gal
Reference: ARB (2007). The California Air Resources Board's EMission FACtors (EMFAC) model was used to calculate emission rates from all motor vehicles, such as passenger cars to heavy-duty trucks, operating on highways, freeways and local roads in California. Model and documentation available online at: /msei/onroad/latest_version.htm
Parameter: EMFAC CO emission = 1,240,205,441,209 g (i.e. 1.24 million tonnes)
Reference: ARB (2007). The California Air Resources Board's EMission FACtors (EMFAC) model was used to calculate emission rates from all motor vehicles, such as passenger cars to heavy-duty trucks, operating on highways, freeways and local roads in California. Model and documentation available online at: /msei/onroad/latest_version.htm
Parameter: EMFAC CO2 emission = 9,202,041,369,972 g (i.e. 9.2 million tonnes)
Reference: ARB (2007). The California Air Resources Board's EMission FACtors (EMFAC) model was used to calculate emission rates from all motor vehicles, such as passenger cars to heavy-duty trucks, operating on highways, freeways and local roads in California. Model and documentation available online at: /msei/onroad/latest_version.htm
Parameter: EMFAC THC emission = 86,242,314,335 g (i.e. 86.24 thousand tonnes)
Reference: ARB (2007). The California Air Resources Board's EMission FACtors (EMFAC) model was used to calculate emission rates from all motor vehicles, such as passenger cars to heavy-duty trucks, operating on highways, freeways and local roads in California. Model and documentation available online at: /msei/onroad/latest_version.htm
Parameter: EMFAC total fuel combustion = 13,639,555,100 gal
Reference: ARB (2007). The California Air Resources Board's EMission FACtors (EMFAC) model was used to calculate emission rates from all motor vehicles, such as passenger cars to heavy-duty trucks, operating on highways, freeways and local roads in California. Model and documentation available online at: /msei/onroad/latest_version.htm
Parameter: FHWA fuel sales = 12,637,497,939 gal
Reference: FHWA (various). US Department of Transportation, Federal Highway Administration - Highway Statistics (volumes 1990 - 2005). Note: FHWA classifies diesel (a.k.a. distillate) fuel as 'special fuels'. Data available online at: http://www.fhwa.dot.gov/policy/ohpi/hss/hsspubs.cfm
Parameter: Heat Content = 125,000 btu / gal
Reference: Murtishaw, S., De La Rue du Can, S,. Price, L., Masanet, E., and Simcich, M. (2005). CALEB: California Energy Balance Database, September 12, 2005. Lawrence Berkeley National Laboratory, Berkeley, CA.
Constant: Molecular weight ratio of CO2 to CH2 = 3.137578797
Reference: IUPAC (2006). ATOMIC WEIGHTS OF THE ELEMENTS 2005 (IUPAC TECHNICAL REPORT). Pure Appl. Chem., Vol. 78, No. 11, pp. 2051–2066, 2006.
Constant: Molecular weight ratio of CO2 to CO = 1.571201102
Reference: IUPAC (2006). ATOMIC WEIGHTS OF THE ELEMENTS 2005 (IUPAC TECHNICAL REPORT). Pure Appl. Chem., Vol. 78, No. 11, pp. 2051–2066, 2006.

● Greenhouse gas emitted per unit activity —

Amount: 8,864 g (i.e. 8.86 kg) of CO2 per gal of Gasoline
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