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

PARALLEL SESSION 6A: TOOLS AND DATABASES 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
Nitrogen balances are established for both cattle-, plant cultivation- and food industry systems and it is
thereby secured that all nitrogen is accounted for, hence all nitrogen inputs to the systems will leave as products
(e.g. milk, meat, manure, crops residues) or emissions (e.g. nitrate, ammonia).
The applied methodology in the present paper is consequential LCA (Weidema et al., 2009) and thereby
follows the international standards on life cycle assessment: ISO 14040 and 14044 and the international
standard on carbon footprints on products: ISO 14067-1. (The default method to be used within Arla foods is
IDF (2010), which is the method developed by the dairy industry.) System expansion is used in all multiple
output processes. For example milk production results in co-production of beef, hence an equal amount of
beef production in Brazil is avoided and the saved emissions from this beef production are deducted from the
environmental impact of milk production. Coproduction of soybean oil together with the determining product
soybean meal is another example of system expansion.
Consequential
(substitution)
Dairy cow
milk
newborn heifer
newborn bull
meat,live weight
dead animal
manure
Attributional
(economic allocation)
PAS2050
(allocation)
IDF
(allocation)
Raising heifer for
milk production
Raising newborn
bull for meat
production
bull calf
dead animal
manure
manure
meat, live weight
dead animal
Raising bull calf
for meat
production
meat, live weight
dead animal
manure
Figure 1. Dairy system with the boundaries for substitution/allocation.
Treatment
Treatment
Destruction
The model also includes switches that enables for, within the same scope, transforming the results to
comply with allocation/average modelling, IDF (2010) guide to standard LCA methodology for the dairy
industry and PAS2050 (Carbon Trust et al., 2010). When these switches are turned on, allocation and average
market mixes are used for the calculations. The system boundaries applied for the different standards are
presented in Figure 1, where the dairy system is used as an example. The dairy system produces milk, meat,
energy (from destruction of dead animals), nutrients contained in the manure and dead cattle for destruction.
In the consequential modelling all the activities are included. When the allocation/average switch is turned
the GHG emissions are economic allocated between milk, meat, energy (from destruction of animals) and the
nutrients in the manure. When the IDF switch is turned on, the GHG emissions are allocated between milk
and meat. But opposed to the allocation/average and PAS2050 switches, the raising of bull calves for meat
production is not part of the milk system, i.e. the export of small bulls for further raising for meat production
are excluded from the inventory. Allocation between milk and meat is based on a method using relationship
between the energy content in the feed ration and milk and meat production. When PAS2050 is turned on
Treatment
Fertiliser
Burning fuel
Cattle meat
fuel
Manure
treatment
nutrients
Treatment
Treatment
Utilisation of fuel
energy
Treatment
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