Life cycle assessment of integrated food chains—a Swedish case study of two chicken meals

Food is a vital human need that not only provides essential nutrition but is also a key part of our social life as well as being a valued sensory experience. However, food, or rather the production chain of food, from primary production (agriculture/aquaculture/fishing) to consumer and beyond, also results in some form of environmental impact, as does transport between steps. There are several life cycle assessment studies of food products, most of them analysing the impact of the food chain of single food items. Still, detailed studies of complete meals are less frequent in the literature. In the Swedish study presented in this article, the environmental impacts of two different chicken meals (homemade and semi-prepared) were analysed. The aim of the study was to gain knowledge of the environmental impact of integrated food chains and also to explore the effect of improvement measures in the post-farm systems. To this end, two chicken meals were chosen for analysis, with two scenarios for each meal; the first scenario reflects the present conditions of the food chain, and the second scenario incorporates a number of improvement actions in the stages after the farm.

Input data to the model were based mainly on previous life cycle assessment (LCA) studies of Swedish food products and studies on wastage and consumer transport. Food engineering data and information from producing companies were used for modelling the industries. The improvement scenario was constructed using insight from a preceding LCA study of a meatball meal (Sonesson et al., Ambio, 34:411–418, 2005a) along with goals set out by a Swedish agreement between representatives from national and regional government, food industry sectors and retailers. The impact assessment was conducted according to Lindfors et al. (Nordic guidelines on life cycle assessment, The Nordic Council of Ministers, Copenhagen, Denmark, 1995), and the following environmental effects were included: global warming potential, eutrophication potential, acidification potential, photochemical ozone creation potential, and use of primary energy carriers and secondary energy.

In terms of energy use, the largest part is used in the steps after the farm for both meal types. Hence, the changes made in the improvement scenario have a significant impact on the total energy use. For the homemade and semi-prepared meal, the reduction is 15% and 20% respectively, not only due to less consumer transport and packaging but also reduction in industry (semi-prepared). Agriculture is also a significant contributor to emissions of greenhouse gases and eutrophying emissions; for the homemade meal, around 40% of the greenhouse gases originate from agriculture, and for the semi-prepared meal, the figure is 50%. The improvement actions with the greatest reduction in greenhouse gases are, again, less consumer transport and, in the case of the semi-prepared meal, the reduction in energy use in industry. Regarding eutrophication, more than 90% of the emissions originate from agriculture. Hence, the only improvement action that has an effect here is the utilisation of raw material downstream in the production chain; a slight reduction in waste still gives a notable reduction in overall eutrophic emissions.

There are two significant areas of research to reduce the impact of meals that are not explored in this study: choice of meal components and production methods in agriculture. However, the aim with this study was to explore if there are further ways of reducing the impact without going into these very complex areas, and our conclusion is that there are effective ways in the post-farm chain to cut emissions that, together with choices of diet and agricultural research, can significantly reduce the impact of our food consumption.

Actions in the post-farm chain that can significantly reduce the environmental impact of a meal are less food thrown away in the household, fewer car trips to the supermarket (e.g. only once a week) and, for semi-prepared food products, more efficient energy use in the food industry. The study shows that consumer actions prove just as important as industrial actions.

Further research is needed to understand the mechanism for the disposal of food, i.e. the reasons for food being wasted, and the relationship between shopping frequency, retail location, size of packaging, etc. in order to reduce the impact of waste and consumer transport.