The role of life cycle assessment in environmental decision making in livestock production

Life cycle assessment (LCA) is nowadays a generally accepted method to gain insight into the environmental
impact along the life cycle of an animal-source food product, and to identify options to reduce this impact.
Besides food provision, however, animal production systems also contribute to other ecosystem services,
such as production of bio-energy or clean drinking water, carbon sequestration, maintenance or enhancement
of biodiversity, or preservation of the landscape. These other ecosystem services are generally ignored in
LCAs of animal-source food, which might favour system with a high animal intensity per ha of land. LCA
studies that do address ecosystem services besides food production can be divided in two categories. The first
category considers other ecosystem services, such as the enhancement of biodiversity or preservation of the
landscape, as another output of the system. In such a multiple-output situation, the environmental impact of
the animal production system is allocated to the multiple outputs (e.g. milk, and other ecosystem services),
using one of the main allocation methods (system expansion, physical or economic allocation). The second
category considers an ecosystem service as another environmental impact category, besides climate change,
eutrophication, etc., and, therefore, aims to incorporate ecosystem services into the LCA framework. These
studies face the complexity of determining characterization factors (modelling the cause-effect chains) of
various ecosystem services. This presentation addresses pros and cons of both approaches, and, more generally,
the strengths and weaknesses of LCA to assess the environmental impact of animal production systems.