A Review of Livestock Methane Emission Factors (2016-CCRP-DS.11) EPA Research Report

Abstract

Teagasc and University College Dublin, with support from the Environmental Protection Agency (EPA) inventory team, reviewed the livestock methane emission factors used in the national greenhouse gas inventory approach for the agriculture sector and assessed potential reduction strategies. Livestock methane emission factors are annual estimates of methane emissions per head. They are used in conjunction with livestock statistics to estimate annual livestock methane emissions. Methane emission factors are computed using country-specific methods or methods provided by the Intergovernmental Panel on Climate Change (IPCC). Currently, Ireland uses tier 2 (country-specific data and emission factors) methods for cattle and tier 1 (default data and emission factors) IPCC methods for the remaining livestock species. The latter are less accurate than the former. The objectives of this desktop study were twofold: first, to evaluate the activity data of Ireland’s national greenhouse gas inventory’s livestock methane emission factors and, second, to update/recommend new, more advanced methods/emission factors for computing Ireland’s tier 1 and 2 livestock methane emissions.