Sustainability of various diets

Transcription

1 Federal Department of Economic Affairs, Education and Research EAER Agroscope Thomas Nemecek Agroscope, LCA research group Zurich, Switzerland EAAP-ATF 27 August I good food, healthy environment

2 Overview A global perspective: Environmental impacts of animal-based food Comparison of animal-based vs. plant-based food Potentials of changed diets A country's perspective: Switzerland Quantify reduction of environmental impacts through optimised diets Identify optimised diets Determine consequences for land use, animal herds and imports Modelling system Scenarios investigated Results of optimisation Environmental impacts Optimised diets Implication for agricultural land use, animal herds and food self-sufficiency Conclusions 2

3 High environmental impacts through animal products 3 Source: Poore & Nemecek (2018), Science 360 (6392),

4 Animal-based food has much higher impacts than plant-based alternatives (on a protein basis) Source: Poore & Nemecek (2018), Science 360 (6392),

5 Changing global diets Animal-product free diets could reduce most environmental impacts by ½ Halving consumption of animal-based products by avoiding the high-impact producers reduce most environmental impacts by ⅓ synergistic effects 5 Source: Poore & Nemecek (2018), Science 360 (6392),

6 Overview of the modelling system Functional unit: Nutrition of the Swiss population System boundary: Food supply + Including upstream processes + Including environmental impacts abroad through feed and food imports to Switzerland Excluding environmental imports from exports Excluding retail, food preparation and consumption Source: Zimmermann et al. (2018), Agroscope Science 55. 6

7 Minimisation of environmental impact (ReCiPe method) Scenarios investigated Additional conditions: 1. Whole agricultural area and arable land in Switzerland used for food production 2. Food exports kept constant at current levels 3. Current deviations from nutritional recommendations are tolerated, but no further increase is allowed Scenario Reference Min ReCiPe FP FP/Cal FoodWaste Current situation Covering nutritional requirements Composition of ration according to food pyramid Composition of ration and energy intake according to food pyramid All preventable food waste during consumption was avoided Source: Zimmermann et al. (2018), Agroscope Science 55. 7

8 Pt *E+06 2'500 2'000 Total environmental impacts can be reduced over 50% 100% ReCiPe Food imports Feed imports 1'500 45% 52% 49% 39% Processing Animals 1'000 Plants 500 Total (less exports) 0 Reference Min ReCiPe FP FP/Cal FoodWaste Target function: Minimisation of ReCiPe Mainly achieved by reducing food impacts, feed imports and animal herds. Further reductions through reduced calorie intake and avoided food waste. Source: Zimmermann et al. (2018), Agroscope Science 55. 8

9 Climate change impacts can be reduced even more kg CO2 eq *E+06 15' % IPCC GWP 100a Total (excluding exports) Food imports Feed imports 10'000 41% 48% 44% 34% Processing Animals Plants 5'000 0 Reference Min ReCiPe FP FP/Cal FoodWaste Target function: Minimisation ReCiPe Source: Zimmermann et al. (2018), Agroscope Science 55. 9

10 Optimised diets differ significantly Quantities before deduction of losses during consumption g/person/day Min ReCiPe Less meat, alcohol, vegetable oils oconstant consumption of dairy products FP FP/Cal Food Waste Reference Reference Estimated energy intake (total of 2360 kcal/person/day) kcal/person/day +More cereals, potatoes, fruits, vegetables, legumes incl. peanuts Min ReCiPe FP FP/Cal Food Waste Nuts Tofu Legumes Beans/Peas Vegetables Fruits Fruit juice Cocoa Alcohol. beverages Confectionery Fats Oils Eggs Fish Meat 1 Dairy products Potatoes Grains 1 (without butter + cream) Target function: Minimisation of ReCiPe Source: Zimmermann et al. (2018), 10 Agroscope Science 55.

11 Implications for Swiss agricultural area use ha 1'000' '905 Perm. grassland extensive 800' ' ' ' ' '295 Perm. grassland medium intensive Perm. grassland intensive 600' ' ' ' ' ' ' '137 19'114 19'114 19'114 19'114 23'719 40'113 40'113 37'377 40' '822 89'352 89'352 89'352 89' ' ' ' ' '041 Other areas Permanent crops Temporary grassland Arable crops 0 Reference Min ReCiPe FP FP/Cal FoodWaste Source: Zimmermann et al. (2018), Agroscope Science Target function: Minimisation ReCiPe

12 Implications for Swiss animal herds Livestock units 1'200'000 1'000' ' ' ' ' '267 27' '491 39'545 44'805 48' ' '275 42'189 94' '265 41'420 42'254 41'589 41'615 78'343 20' '901 89' ' ' ' ' '660 42'159 51'540 41'603 41'603 12'584 88'771 98' ' '794 91' ' '048 Reference Min ReCiPe FP FP/Cal FoodWaste Laying hens Broilers Pigs Goats Sheep Horses Calf fattening Beef fattening Suckler cows Cattle rearing Other dairy cows 5600 kg 6800 kg 7500 kg Dairy cows Target function: Minimisation ReCiPe 12 Source: Zimmermann et al. (2018), Agroscope Science 55.

13 Conclusions Even the lowest-impact animal-based products have higher environmental impacts than plant-based alternatives Reducing consumption of high-impact products by avoiding high-impact producers creates synergistic mitigation effects The environmental impacts of the diet of the Swiss population could be reduced by over 50 % in the optimized scenarios by reducing feed imports, food imports and animal production impacts The composition of the average diet needs significant changes: -70% meat +35% grains and potatoes Milk consumption remaining at current level Optimised diet would be closer to nutritional recommendations Swiss agriculture would focus mainly on crop and dairy production Self-sufficiency of Swiss food supply would increase 13

14 Thank you for your attention Thomas Nemecek Agroscope good food, healthy environment 14