may be more efficient than smaller operations, there may be trade-offs with respect to water quality, manure management, and other effects.

The LCA framework is very good at characterizing the effects of both production and consumption, particularly with respect to GHG emissions and energy usage. While the framework can be used to also characterize human health (e.g., via quality-adjusted life years) and other social impacts of production and consumption, Keoleian reported, “uncertainty increases tremendously when you start to look at some of these other effects.” However, the LCA framework can be very useful in identifying “order of magnitude” trade-offs between health and environmental impacts. LCA can also be used to evaluate economic impacts of production and consumption, including both private and social costs (e.g., the “social cost of carbon,” that is, monetized damages associated with increasing carbon emission) (Interagency Working Group on Social Cost of Carbon, 2010).

Research and Data Needs

Data needs depend on the question(s) being addressed. For example, if a goal is to characterize differences in production methods, then data would be needed for each type of production method (i.e., as opposed to industry average). With respect to data needs for specific stages of the food life cycle, many working group participants indicated there could be better data on the generation of food waste (e.g., data on spoiled milk is decades old) and better data on consumption patterns. Spatially explicit production data will also be necessary to capture impacts of categories that have spatially influenced characterization factors (e.g., water use, eutrophication, land use).


Participants in this group spent most of their time discussing challenges to characterizing the soil, water, and other environmental consequences of the food system, as reported back to the group at large by Justin Derner, research leader for the Rangeland Resources Research Unit of the USDA Agricultural Research Service.

The Challenge of Heterogeneity

Working group participants discussed several major challenges to analyzing the external costs of animal production. One main challenge is the heterogeneity among sites with respect to practices, soils, climate, landscape, plant communities, and data (e.g., some sites have plentiful data, others none). Also, effects occur across variable spatial scales (e.g.,

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