58.2 Organic, local and vegetable based food sourcing as a sustainable strategy – what data are available?

Michael Søgaard Jørgensen , Technical University of Denmark, Department of Management Engineering, Lyngby, Denmark
The paper describes at a conceptual level the climate aspects of food production and consumption and introduces different strategies, which can reduce the climate impact from food in general and especially at food events – without increasing other environmental impacts of food production and consumption. As part of discussing these topics the paper describes available data. Besides climate impact, impact on land use, biodiversity, chemical emissions, nutrient flows and ground water levels are important environmental impacts related to food production and consumption.
All parts of the life cycle of a food product from fishing and farming through processing and distribution and until the final processing and consumption have climate impacts and also other environmental impacts. The size of the impacts depends on the effectiveness of the processes in the different parts of the life cycle, including the wastage generated. The effectiveness can be seen as impacts per kilogram food or per unit if nutrients. The climate impact depends on the food products which are produced, because there are big differences among the climate impact from different types of food. Especially animal food has a high climate impact with big differences among different types of meat (due to the production of fertilizer for fodder production and for ruminant the evaporation of methane from the digestion) and among different types of fish (depending on the distance of sail per kilogram of fish). Also vegetables grown in greenhouses heated by fossil fuel have a high climate impact. A so-called CO2 food pyramid has been developed as a simple tool for decision about what food products to choose for a meal. The pyramid is based on life cycle based data about 150 food products from a Swedish project managed by Carlsson-Kanyama. A food event related meal like a hot dog has very different climate impact depending on the type of sausage. Soy protein: 80 gram CO2-equivalentes. Chicken: 150 CO2-equivalentes. Pork: 250 gram CO2-equivalentes. Lamb: 670 gram CO2-equivalentes. For the Danish average diet 50% of the climate impact comes from animal products (dairy products and different types of meat and meat products).
The importance of land use can be seen from the fact that 62% of the Danish land is cultivated, whereof 80% are used for the growing of animal fodder. The importance of land use in other countries is seen from the fact that Denmark is imported 25% of its animal fodder, especially soy protein. The climate impact from soy protein may be very high since this type of fodder when grown in South America often is grown on land that earlier was covered with trees or other types of plants. The clearing of the land causes a substantial climate impact for many years. The climate impacts from agriculture can be divided into energy-related impacts covering the use of fossil fuels for vehicles and machines (15% of the climate impact) and non-energy related emissions, which are related to the chemical processes in the soil from application of fertilizer and manure, oxidation of carbon in the soil etc. (85%). These types of impacts vary a lot from farm to farm, depending on the type of agriculture and the local farm management, which implies that food procurement for events could focus on these aspects. Organic farming has a number of advantages related to nature, environment and health, compared to conventional agriculture, to bigger diversity, the use of organic manure, lower nitrogen surplus in the soil etc. The climate impact of organic food compared to conventional food differs depending on the type of food. The climate impact of greenhouse vegetables are bigger for organic vegetables due to lower yield per m2 greenhouse, while the impact of organic pork is lower due to lower nitrogen surplus and thereby less laughter gas product gas emission from the growing of fodder for the pigs. The type of soil influences also the climate impact. Agriculture on drained soil contributes more to climate impact because of the oxidation of the carbon in the soil into carbon dioxide and at the same a low yield on this type of soil.
Analyses of the climate impact from transportation of food shows compares to the climate impact of the food product itself show that for fruit the impact from transportation maybe 50% of overseas fruit, while for animal products the transportation may contribute around 15%. This implies that local products have a lower climate impact compared to products transportation a long distance. However, local vegetables grown in greenhouses outside the season has a higher impact compared to products grown in areas where greenhouses are not needed.
An assessment of household food waste from the UK shows that 20% of the food ends as waste (not including the peels from carrots etc.). Half of the food waste is processed food products, while the other 50% are food that has not been processed yet.
Based on the available data for climate impact a climate strategy for food at events should be based on: a substantial amount of vegetable products and a limited amount of animal products, a strategy for reduction of the food waste, products from organic agriculture and/or from conventional farms with a low surplus of nutrients and local products grown within the seasons. Greenhouses should be heated with renewable energy.