LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PLENARY SESSION 2: METHODOLOGICAL CHALLENGES FOR ANIMAL PRODUCTION SYSTEMS 8 th Int. Conference on
LCA in the
Agri-Food Sector, 1-4 Oct 2012
Figure 1. Environmental impact contribution analysis by life cycle stage to IMPACT 2002+ categories
Post-farm gate stages of the fluid milk life cycle also contribute significantly to environmental impacts. The
processing stage is the dominant contributor to both terrestrial ecotoxicity (89%) and aquatic ecotoxicity
(65%). This is a direct result of the on-site waste water treatment model chosen for this analysis; in particular,
the use of a unit process from Ecoinvent that is specific for whey processing, which includes emissions
of phosphorus due to cleaning in place technologies and aluminum, which in the data set apparently arises
from the use of alum as a flocculation aid. These emissions are highly uncertain, and may not represent practices
at specific locations, therefore these impacts should be considered as warning flags, not assertions of
actual impact. The negative contribution to land occupation from processing is the result of out of date milk
used as pig feed displacing corn and soymeal in those animal’s rations.
Normalisation of environmental impacts (Figure 2), based on 56.7 kg per capita annual fluid milk consumption,
with normalisation factors specific to the US (Lautier et al., 2010) suggests that aquatic eutrophication,
aquatic ecotoxicity, terrestrial acidification/nitrification, aquatic acidification and carcinogens are important
categories on which to focus environmental improvement efforts. The y-axis in the normalisation analysis
represents the fractional contribution of each category to total US impacts per category. Phosphorus runoff
from land applied manure and fertiliser drives the contribution of aquatic eutrophication.
Figure 2. Normalisation results for the US; analysis based on per capita consumption of fluid milk
The economic results, which focus on positive economic contributions, rather than damages, present contributions
of the US dairy supply chain to the US economy in terms of 2008 employment, labour income and
value added (Table 1). Dairy contributed 407,071 jobs to the US economy, more than 5% of all direct jobs in
US agriculture. Dairy Cattle and Milk Production constituted 68% of dairy employment, while the process-
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