Last reviewed on 08-08-2024

Documentation of California's Greenhouse Gas Inventory (2024 Edition - Last updated on 08-08-2024)

♦ Category: Agriculture, Forestry and Other Land Use

IPCC: 3A1ai - Livestock - Enteric Fermentation - Cattle - Dairy Cows
Sector: Agriculture & Forestry : Enteric Fermentation : Cattle

♦ Activity: Livestock population - Dairy cows

♦ Greenhouse gas: Methane ( CH4 )

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► Year 2020 —

● Greenhouse gas emission estimate —

Amount: 247,716 tonnes of CH4 Emitted (6,192,903 tonnes CO2 Eq.)
Basis: Model
Calculation: Cattle enteric fermentation model
Reference: USEPA (2013). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2011 U.S. Environmental Protection Agency. Annex 3.10: Methodology for Estimating CH4 Emissions from Enteric Fermentation. https://www.epa.gov/sites/production/files/2015-12/documents/us-ghg-inventory-2013-annexes.pdf

● Activity level used in calculations —

Activity: Livestock population = 1,713,053 head of Dairy cows
Basis: Model
Calculation: Cattle life cycle model
Reference: USEPA (2013). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2011 U.S. Environmental Protection Agency. Annex 3.10: Methodology for Estimating CH4 Emissions from Enteric Fermentation. https://www.epa.gov/sites/production/files/2015-12/documents/us-ghg-inventory-2013-annexes.pdf
Reference: USDA and CDFA, various years. The USDA agriculturlal census provides statewide milking cow populations every five years (2002, 2007, 2012). The milking cow population for intervening years are interpolated from CDFA growth profiles for non-census years. https://www.agcensus.usda.gov/Publications/

● Parameters and Constants used in calculations —

Parameter: Not applicable
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: 144,605 g (i.e. 144.61 kg) of CH4 per head of Dairy cows
3,615,127 g (i.e. 3.62 tonnes) of CO2eq. per head of Dairy cows