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: Agriculture, Forestry and Other Land Use

IPCC: 3a2i - Livestock - Manure Management - Poultry
Sector: Agriculture & Forestry : Manure Management : Poultry

♦ Activity: Livestock population - Hens 1+ yr

♦ Greenhouse gas: Methane ( CH4 )

► Year 1990 —

● Greenhouse gas emission estimate —

Amount: 4,571 tonnes of CH4 Emitted (95,994 tonnes CO2 Eq.)
Basis: Calculation
Calculation: [Livestock population] * [Typical animal mass] * [Volatile solids production rate] * [Average number of days per year] * [State weighted methane conversion factor] * [Maximum methane production capacity] * [Methane density]
Reference: USEPA (2007). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2005. United States Environmental Protection Agency. EPA 430-R-07-002. and Annex 3.10: Methodology for Estimating CH4 and N2O Emissions from Manure Management. April 15, 2007. Washington DC. http://www.epa.gov/climatechange/emissions/usgginv_archive.html

● Activity level used in calculations —

Activity: Livestock population = 30,400,000 head of Hens 1+ yr
Basis: Data
Reference: Wirth, T. (2007). Personal communication between Neva Lowery of CA Air Resources Board and Tom Wirth, Greenhouse Gas Inventory Source Lead, US Environmental Protection Agency, March 2007.

● Parameters and Constants used in calculations —

Parameter: Maximum methane production capacity = 3.900E-04 m3 / g
Reference: USEPA (2007). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2005. United States Environmental Protection Agency. EPA 430-R-07-002. and Annex 3.10: Methodology for Estimating CH4 and N2O Emissions from Manure Management. April 15, 2007. Washington DC. http://www.epa.gov/climatechange/emissions/usgginv_archive.html
Parameter: State weighted methane conversion factor = 0.0878
Reference: Wirth, T. (2007). Personal communication between Neva Lowery of CA Air Resources Board and Tom Wirth, Greenhouse Gas Inventory Source Lead, US Environmental Protection Agency, March 2007.
Parameter: Typical animal mass = 1.8 kg / head
Reference: USEPA (2007). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2005. United States Environmental Protection Agency. EPA 430-R-07-002. and Annex 3.10: Methodology for Estimating CH4 and N2O Emissions from Manure Management. April 15, 2007. Washington DC. http://www.epa.gov/climatechange/emissions/usgginv_archive.html
Parameter: Volatile solids production rate = 10.1 g / kg / day
Reference: Wirth, T. (2007). Personal communication between Neva Lowery of CA Air Resources Board and Tom Wirth, Greenhouse Gas Inventory Source Lead, US Environmental Protection Agency, March 2007.
Constant: Average number of days per year = 365.2425 day
Reference: USNO (2004). U.S. Naval Observatory, Astronomical Applications Department, Leap Years. Accessed online at: http://aa.usno.navy.mil/faq/docs/leap_years.php
Constant: Methane density = 662 g / m3
Reference: USEPA (2007). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2005. United States Environmental Protection Agency. EPA 430-R-07-002. and Annex 3.10: Methodology for Estimating CH4 and N2O Emissions from Manure Management. April 15, 2007. Washington DC. http://www.epa.gov/climatechange/emissions/usgginv_archive.html
Constant: Global warming potential of CH4 = 21
Reference: IPCC (1996). Second Assessment Report. Climate Change 1995: WG I - The Science of Climate Change. Intergovernmental Panel on Climate Change; J.T. Houghton, L.G. Meira Filho, B.A. Callander, N. Harris, A. Kattenberg, and K. Maskell (eds.); Cambridge University Press. Cambridge, U.K.

● Greenhouse gas emitted per unit activity —

Amount: 150 g of CH4 per head of Hens 1+ yr
3,158 g (i.e. 3.16 kg) of CO2eq. per head of Hens 1+ yr
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