A method was developed for designing ‘fair’ diets (not using more than globally available arable land per capita) and for assessing the sustainability of such diets. The diets were based on the principle of ‘ecological leftovers’ for livestock production, i.e. raising livestock on pasture and by-products not suitable for or wanted by humans. The method was applied to Sweden using three different scenarios for livestock production, all taking the starting point that semi-natural pastures should be grazed by ruminants for reasons of biodiversity conservation. The scenarios also included differing use of by-products (from crop production and food processing) to either boost milk production (I-Milk scenario) or produce eggs and pig meat (E-Milk and Suckler scenarios). In I-Milk, milk and meat were produced in intensive systems in which dairy cows and their offspring only grazed to a limited extent, resulting in the human diet containing recommended levels of dairy products (350ml milk per day) and meat twice a week. Milk could also be exported. In E-Milk, pasture was used more for dairy cows and their offspring, resulting in fewer animals and less milk (150ml milk per day) and four servings of meat per week. In the Suckler scenario, pasture was grazed by suckler herds providing no milk but meat four times per week. The environmental impacts of the diets were assessed using the planetary boundaries framework. The results showed substantially lower environmental impacts compared with the average current Swedish diet, but the strict absolute climate boundary and the N and P input boundaries were still exceeded for all diets. The approach adopted, of letting the ecological resource capacity act as the constraining factor for livestock production, is in line with agroecology principles and efficient use of land to improve food security, and could be useful in discussions about sustainable consumption of animal products

The Western diet is characterized by high meat consumption, which negatively affects the environment and human health. Transitioning toward eating more plant-based products in Western societies has been identified as a key instrument to tackle these problems. However, one potential concern is that radically reducing meat in the current diet might lead to deficiencies in nutritional intake. In this paper, we explore a scenario in which meat consumption in Sweden is reduced by 50% and replaced by domestically grown grain legumes. We quantify and discuss the implications for nutritional intake on population level, consequences for agricultural production systems and environmental performance. The reduction in meat consumption is assumed to come primarily from a decrease in imported meat. We use data representing current Swedish conditions including the Swedish dietary survey, the Swedish food composition database, Statistics Sweden and existing life cycle assessments for different food items. At population level, average daily intake of energy and most macro- and micro-nutrients would be maintained within the Nordic Nutrition Recommendations after the proposed transition (e.g., for protein, fat, zinc, vitamin B12 and total iron). The transition would also provide a considerable increase in dietary fiber and some increase in folate intake, which are currently below the recommended levels. The transition scenario would increase total area of grain legume cultivation from 2.2% (current level) to 3.2% of Swedish arable land and is considered technically feasible. The climate impact of the average Swedish diet would be reduced by 20% and the land use requirement by 23%. There would be a net surplus of approximately 21,500 ha that could be used for bioenergy production, crop production for export, nature conservation, etc. Implementation of this scenario faces challenges, such as lack of suitable varieties for varying conditions, lack of processing facilities to supply functional legume-based ingredients to food industries and low consumer awareness about the benefits of eating grain legumes. In sum, joint efforts from multiple actors are needed to stimulate a decrease in meat consumption and to increase cultivation and use of domestically grown grain legumes.

Multifunctional agriculture provides noncommodity functions and services along with food, feed and bioenergy feedstocks, for example by preserving or promoting biodiversity, improving soil fertility, mitigating climate change and environmental degradation, and contributing to the socio‐economic viability of rural areas. Producing biomass for bioenergy from low‐input perennial species mixtures on marginal land has the potential to support biodiversity and soil carbon sequestration in synergy with greenhouse gas mitigation. We compared biomass production in species‐rich mixtures of perennial grasses, legumes and forbs with pure‐stand grasses and relatively species‐poor mixtures under different nitrogen fertilization regimes. Field experiments were performed on different types of marginal land, that is agricultural field margins and land with poor soil fertility, at four sites in southernmost and western Sweden. Biomass production was measured for three years in perennial grasses grown as pure stands, in legume‐grass mixtures, and legume‐grass‐forb mixtures across a species richness gradient. In unfertilized species‐rich mixtures, average biomass yields per experimental site and year were in the range from 3 to 9 metric ton DM ha⁻¹ yr⁻¹. While the most productive pure‐stand grasses fertilized with 60–120 kg N ha⁻¹ yr⁻¹ often produced higher biomass yields than unfertilized mixtures, these differences were generally smaller than the variations between years and sites. Calculations of climate impact using the harvested biomass for conversion to biogas as vehicle fuel showed that the average greenhouse gas emissions per energy unit were about 50% lower in unfertilized systems than in treatments fertilized with 100–120 kg N ha⁻¹ yr⁻¹. Our findings thereby show that unfertilized species‐rich perennial plant mixtures on marginal land provide resource‐efficient biomass production and contribute to the mitigation of climate change. Perennial species mixtures managed with low inputs thus promote synergies between productivity and biodiversity in the perspective of climate‐smart and multifunctional biomass production.