Environmental impacts of organic and conventional diets - effect of changing towards more plant-based food

Summary

An organic diet has the potential to create a positive effect on biodiversity and ecotoxicity, whereas climate impact is often at a similar level for organic and conventional diet, and land use per kg food is higher for organic food. The contribution of organic food production to the sustainability goals depends to a high degree on the composition of the organic diet.
The aim of the present study was to investigate the environmental effect of changing from the current Danish conventional diet with an average composition of food items to an organic diet with same composition of food items. Furthermore, to investigate for both type of diets – the effect of changing from the current composition of the diet to a more plant-based diet. The environmental impact investigated was the climate effect, the effect on land use, on plant diversity on cultivated area, eco toxicity, pesticide residues in foods, and animal welfare.
When changing from the current composition of the conventionally diet to a more plant-based diet, both carbon footprint and land use was reduced with around 30%. Ecotoxicity was reduced with 38%, as a high proportion of the contribution hereof came from the animal-based foods, whereas the amount of food with risk of pesticide residues was increased with 21% as pesticide residues were only found in plant-based foods.
When changing from a conventionally to an organically produced diet, carbon footprint was not affected, but land use was increased. However, with the plant based organic diet, land use was 5% lower than in the current conventionally diet. The loss of plant species on the cultivated area for the organic diet was only half of that in the conventional diet, ecotoxicity of an organic diet was nearly 4 times lower, and the amount of food with risk of pesticide residues was more than 10 times lower that in the conventional diet. Finally, an organic diet has a positive effect on animal welfare.