Organic agriculture has sustained consistent growth in the U.S. over the past decade, but very little systemic environmental impact benchmarking has been performed. This study is the first life cycle assessment (LCA) of a large-scale, vertically integrated organic dairy in the U.S. The focus of this study was Aurora Organic Dairy (AOD), a leading provider of private label organic milk in the US. Over the time frame of analysis, April 2007 to March 2008, AOD owned or leased six dairy farms, located in Colorado and Texas, as well as a milk processing plant, located in Colorado. Primary data from AOD 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 transport of packaged milk to product end of life disposal. Overall GHG emissions were 7.98 kg CO2e per gallon of packaged liquid milk purchased at the retail location. The major GHG contributors include enteric fermentation (25% of total) and feed production (17% of total). The energy consumption for the entire system was 72.6 MJ (1.65 gallons of gasoline equivalent LHV) per gallon of packaged liquid milk. Potential strategies for reducing the system GHG emissions are discussed including wind energy, animal husbandry techniques, biodiesel, photovoltaic energy, and anaerobic digestion.
CSS Publication Number:
milk production system
greenhouse gas emissions
Cashman, Sarah, Keri Dick, Derek Przybylo and William Walter. 2009. Charting the Course for Sustainability at Aurora Organic Dairy – Phase 1: Energy & Greenhouse Gas Life Cycle Assessment. Master's Thesis, University of Michigan: Ann Arbor: 1-98.