title: Life cycle energy and greenhouse gas analysis of a large-scale vertically integrated organic dairy in the United States.
abstract: In order to manage strategies to curb climate change, systemic benchmarking at a variety of production scales and methods is needed. This study is the first life cycle assessment (LCA) of a large-scale, vertically integrated organic dairy in the United States. Data collected at Aurora Organic Dairy farms and processing facilities were used to build a LCA model for benchmarking the greenhouse gas (GHG) emissions and energy consumption across the entire milk production system, from organic feed production to post-consumer waste disposal. Energy consumption and greenhouse gas emissions for the entire system (averaged over two years of analysis) were 18.3 MJ per liter of packaged fluid milk and 2.3 kg CO(2 )equiv per liter of packaged fluid milk, respectively. Methane emissions from enteric fermentation and manure management account for 27% of total system GHG emissions. Transportation represents 29% of the total system energy use and 15% of the total GHG emissions. Utilization of renewable energy at the farms, processing plant, and major transport legs could lead to a 16% reduction in system energy use and 6.4% less GHG emissions. Sensitivity and uncertainty analysis reveal that alternative meat coproduct allocation methods can lead to a 2.2% and 7.5% increase in overall system energy and GHG, respectively. Feed inventory data source can influence system energy use by -1% to +10% and GHG emission by -4.6% to +9.2%, and uncertainties in diffuse emission factors contribute -13% to +25% to GHG emission.
authors.affiliation: Center for Sustainable Systems, School of Natural Resources and Environment, University of Michigan, 440 Church Street, Dana Building, Ann Arbor, Michigan 48109-1041, United States. mcheller@umich.edu
authors.forename: Martin C
authors.initials: MC
authors.lastname: Heller
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Keoleian
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data; D058572:Carbon Footprint / Q000706:statistics & numerical data*; D003247:Conservation of Natural Resources / Q000379:methods*; D003612:Dairying / Q000379:methods / Q000706:statistics & numerical data*; D004736:Energy-Generating Resources / Q000706:statistics & numerical data*; D004784:Environmental Monitoring; D017752:Greenhouse Effect; D014481:United States
chemical_list: D000393:Air Pollutants