|Rotz, Clarence - Al|
|THOMA, GREG - University Of Arkansas|
Submitted to: International Conference on Greenhouse Gasses and Animal Agriculture
Publication Type: Abstract Only
Publication Acceptance Date: 1/20/2022
Publication Date: 6/6/2022
Citation: Rotz, C.A., Thoma, G. 2022. Life cycle greenhouse gas emissions from beef and dairy production in the United States[abstract]. International Conference on Greenhouse Gasses and Animal Agriculture. P.1.
Interpretive Summary: No Interpretive Summary is required for this Abstract Only. JLB.
Technical Abstract: Because substantial quantities of methane are produced by cattle, many studies are focusing on quantifying and reducing greenhouse gas emissions in dairy and beef production. Recent life cycle assessments have quantified annual emission related to beef cattle production in the United States to be 243 ± 26 Tg CO2e and that for dairy farms as 99 ± 9 Tg CO2e. Together these represent about 5% of that estimated as total annual greenhouse gas emission of the country. For the full life cycle of beef meat and milk, national emissions are estimated to be about 290 Tg CO2e and 140 Tg CO2e, respectively. These emission values are sensitive to the global warming potential used for methane. Because methane breaks down relatively fast in the atmosphere compared to carbon dioxide, models are being developed that consider change in rate as well as amount of emission. Using a model referred to as GWP* and estimated annual increases in methane from U.S. cattle reduces the emissions in CO2e by 25-30%. Mitigation strategies are being developed and tested to reduce emissions in cattle production. Because about 60% of the total emission related to cattle is from methane, mitigation is primarily focused on enteric and secondarily on manure sources. The ultimate goal in mitigation is to obtain carbon neutral production where there is no net effect on global warming. Use of the GWP* model indicates that if a 1% annual reduction in methane emission from cattle is maintained, the result is no effect of U.S. cattle on global warming. This is an ambitious but possible current goal. As methane emission is reduced though, greater portions must be reduced to offset the emission of carbon dioxide and nitrous oxide. To truly reach carbon neutrality, these other emission sources must also be eliminated or offset by carbon storage.