How did our eating habits, and food production, change between 1870 and 2000? And how have these changes in turn affected our environment? Tina Schmid Neset has studied these questions at the local level and is now presenting her findings in a doctoral dissertation at Water and Environmental Studies ¬ (Tema V), Linköping University, in Sweden.

The object of her study is the medium-sized city Linköping and its residents over the course of 130 years. She shows that the area needed per person today to produce food has diminished to one quarter of what it was in 1870. Today only 0.3 hectares per person would be needed if all food were produced locally.

However, in reality, the area in use per person is nearly twice as great, that is, 0.6 hectares, which is due to the fact that much of our food is imported and in some cases is produced using less intensive agricultural methods.

The dissertation discusses how today’s food production can be made more sustainable by reducing the use of finite resources like phosphorous and fossil energy. Tina Schmid Neset shows how the recycling of phosphorous, which was widespread in 1870, with the outhouses of that time, had virtually ceased by 1950. Linköping’s first water purification plant came on steam in 1952, when nearly all inhabitants had installed water closets. In 1972 equipment was installed to separate phosphorous-rich sludge. Since then the recycling of phosphorous has been slowly increasing. Today roughly one fifth of all phosphorous is reused as fertilizer.

At the global level, today‚Äôs rapid urbanization is a huge challenge to food production, according to Tina Schmid Neset. Phosphorous is a finite resource, and it is a ‚Äúnon-negotiable duty‚ÄĚ to drastically reduce the losses of phosphorous in an urban purification system. This in turn is predicated upon a greater component of local production, in order to close the ecosystem.

Tina Schmid Neset also shows how reduced consumption of animal products would greatly decrease the land area needed per person to produce food. With a fully vegetarian diet, it would be possible to cut that area in half and considerably reduce the use of resources.

The dissertation is titled Environmental imprint of human food consumption.

Tina-Simone Schmid Neset can be reached at cell phone: +46 709-732720; e-mail: tinsc@tema.liu.se.