Human food consumption has changed from the late 19th century to the turn of the millennium, and so has the need for resources to sustain this consumption. For the city of Linköping, situated in southeastern Sweden, the environmental imprint of an average inhabitant’s food consumption is studied from the year 1870 to the year 2000. The average consumer is the driving factor in this study, since changes in food consumption have a direct influence on the environmental imprint. This thesis analyses the environmental imprint of human food consumption from a historical perspective, by applying two different methods. An analysis of the average Swedish food consumption creates the basis for a material flow analysis of nitrogen and phosphorus, as well as a study of the spatial imprint.
Emissions of nitrogen and phosphorus into the hydrosphere have decreased over this period for the system of food consumption and production for an average consumer, while the input via chemical fertilizer has increased significantly. The efficiency of this system could be increased if for instance more phosphorus in human excreta would be reused within the system instead of large deposition and losses into the hydrosphere. The spatial imprint of human food consumption shows, given the changing local preconditions, that less space would be needed for regional production of the consumed food. However, the share of today’s import and thus globally produced food doubles this spatial imprint.
The results of this study show not only a strong influence of the consumption of meat and other animal products on the environmental imprint, but also great potential in the regional production of food. In the context of an increasing urban population, and thus additional billions of people who will live at an increasing distance from the agricultural production land, concern for the direct effects of our human food consumption can be of decisive importance for future sustainable food supply.