Another major contributor to all impact categories was food loss and waste.

The impact remained constant or were reduced in 15 of the 18 impact categories including a 6% reduction in global warming and 22% reduction in particulate matter formation. We evaluated the sensitivity associated with greening of the electric grid in which the Northeast US power grid, which has a larger percentage of renewables, was used as the source of electricity for all systems.

Because electricity use is an important contributor to many of the potential impacts throughout the full chain, reducing electricity use is an important mitigation strategy. Mitigation strategies for reducing these environmental impacts are normally specific to the impact category. Categories where most of the impact occurred post farmgate were fossil resource scarcity, freshwater ecotoxicity, freshwater eutrophication, human carcinogenic toxicity, human non-carcinogenic toxicity, ionizing radiation, marine ecotoxicity, and terrestrial ecotoxicity. These categories were fine particulate matter, global warming, land use, mineral resource scarcity, ozone formation, stratospheric ozone depletion, terrestrial acidification, and water consumption. In 13 of the categories, the major sources of impact were related to cattle production, and for 10 of these categories, cattle production and related upstream sources contributed more than half of the total impact. A set of 18 environmental impact categories were quantified, and important sources of each were identified.

Process level simulation of archetypical cattle production systems throughout the nation were combined with information gathered for harvest, processing, retail, and consumption of beef to provide inventory data for a cradle-to-grave life cycle assessment. A need exists for a national-scale full life cycle assessment of beef production through consumption in the United States. Life cycle assessments of have been completed documenting the environmental sustainability of beef, but these studies have often focused on specific cattle production systems with an emphasis on global warming potential.

Mep modeler 23