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Transforming the global food system is necessary to avoid exceeding planetary boundaries. A robust evidence base is crucial to assess the scale and combination of interventions required for a sustainable transformation. We developed a risk assessment framework, underpinned by a meta-regression of 60 global food system modeling studies, to quantify the potential of individual and combined interventions to mitigate the risk of exceeding the boundaries for land-system change, freshwater use, climate change, and biogeochemical flows by 2050. Limiting the risk of exceedance across four key planetary boundaries requires a high but plausible level of ambition in all demand-side (diet, population, waste) and most supply-side interventions. Attaining the required level of ambition for all interventions relies on embracing synergistic actions across the food system.

In Ethiopia, children and adults face a double burden of malnutrition, with undernutrition and stunting coexisting with non-communicable diseases. Here we use a framework of comparative risk assessment, local dietary surveys and relative risks from large observational studies to quantify the health and environmental impacts of meeting adult and child recommended daily protein intakes in urban Addis Ababa. We find that plant-based foods, especially legumes, would have the lowest environmental impact and substantially increase life expectancy in adults, while animal-source proteins could be beneficial for children. This context-specific approach—accounting for regional constraints and trade-offs—could aid policymakers in developing culturally appropriate, nutritionally adequate and sustainable dietary recommendations. Optimization models using locally adapted constraints and trade-offs demonstrate that adult populations in urban Addis Ababa, Ethiopia, could benefit from increased legume consumption, while children would gain from increased animal protein intake. This approach could inform policy and dietary recommendations in low- and middle-income countries.

Sustainable development of India’s food system must ensure a growing population is fed while minimizing both widespread malnutrition and the environmental impacts of food production. After assessing current adequacy of nutrient supplies at the national level, associated natural resource use (land, fresh water) and greenhouse gas (GHG) emissions, we apply an integrated subnational environmental and nutritional optimization approach to explore resource constraints that might limit the achievement of national food self-sufficiency goals. We find that India currently has the capacity to produce sufficient amounts of nutritious foods, supplying vitamins and minerals that would mostly exceed requirements. Regional cropland use could be reduced by up to 50%, water demand by up to 65% and combined resource inputs by up to 40% while still supporting adequate nutrition. Associated GHG emissions would decline by 26–34% and could possibly be sequestered in agroforestry systems. Such dietary shifts could lower the number of diet-related premature deaths by 14–30%. Achieving these potential gains, however, would require a major transition from current production and consumption patterns, particularly of refined cereals, to free-up resources for more traditional and nutritious foods. An integrated subnational environmental and nutritional optimization approach indicates that, with a transition from current production and consumption patterns, India has the capacity to achieve national food self-sufficiency goals while reducing regional cropland use, water demand and GHG emissions.

Food production is responsible for approximately 17% of Germany's greenhouse gas (GHG) emissions. After retail, out-of-home catering is the second largest food sales channel in Germany. A variety of means on both the supply and demand side are necessary to stimulate, facilitate and encourage a more sustainable development and minimise GHG emissions in this sector. Nudges are one of these. This paper's focus lies on the demand side. Set in real-world laboratories, we use a standardised empirical approach to compare different nudging interventions belonging to the area of physical environment and consumers’ choice making process. We compare the effects of the same intervention across different settings and the effect of different, sequential nudging interventions in the same setting. Data was collected in eight workplace and school cafeterias in Germany over two project iterations (2016/2017; 2019/2020). A similar intervention design was applied. Comparability was assured by a harmonised menu. The first project iteration revealed that only one nudge (top menu position, +22.5%) led to significant increases in sustainable food choices, while results from the second iteration showed that all nudge interventions (best counter position, +11.6%; top menu position, +6,9%; label plus information, +15.9%) positively influenced consumer choice. Possible explanations such as the stricter compliance to the experimental design in the cafeterias but also societal developments such as the appearance of the Fridays for Future movement are discussed. As results vary between specific locations and settings, our findings suggest that nudges need to be adjusted to situational conditions for achieving highest efficacy.

When distributed equally, the total amount of food produced worldwide could sufficiently meet current global demand. Still, malnutrition in the form of nutrient deficiencies continues to prevail in both low- and high-income countries. At the same time, natural resource use for agriculture is reaching or exceeding environmental boundaries. By integrating a comprehensive micronutrient scoring method with data on agricultural water demand, this analysis aims to re-evaluate the global water-use efficiency of dietary nutrient production. A stronger reliance on more nutrient-dense foods could lead to higher water-use efficiencies, though dietary water footprints were likely to increase overall. With a more detailed focus on plant and animal foods, we find that most dietary protein sources show comparable water-use efficiencies, and thus can be drivers for agricultural water demand. Animal foods, besides having a unique nutrient profile, often do not compete directly with crops for the same water resources. However, a significant reduction in the demand for utilizable freshwater resources could be achieved by reducing the amount of feed crops in ruminant diets. Water-use efficiency in the production of food must not only take into account quantities and yields, but also the nutrients and dietary impacts. Animal and plant foods show little difference in this demand efficiency, and best serve as complimentary rather than substitutable foods.

The Middle East and North Africa (MENA) region stands out globally both for the immensity of its energy resources, and the paucity of its freshwater resources. Most energy extraction and conversion technologies have associated freshwater demand, and in the MENA region these account for 2 % of the available sustainable supply. We examine how this demand could change over the 21st century, assuming growth in population and economic output, and considering three alternative pathways for energy efficiency, carbon intensity, and energy exports from the region. We find that in the pathway marked by improved efficiency, a transition to renewable energy sources, and declining energy exports, water consumption for energy is twice as high as today's values by the end of the century. By contrast, in the pathway marked by continued commitment to fossil resource extraction, use, and export, water demand for energy might rise by a factor of five. If the region were to maintain high levels of energy exports, but would substitute the export of fossil fuels by an equivalent amount of electricity derived from sunlight, a freshwater volume comparable to the household needs of up to 195 million people could be saved.

Intermittency is often cited as the single greatest hurdle to making a transition from a fossil-based power system to one based on renewables. This study shows that a network of solar power plants, located in deserts, could provide significant baseload in four world regions, suggesting that decarbonization of the power system may be possible and affordable, even if no new technologies come online.

The sufficient supply of food and energy requires large amounts of fresh water. Mainly required for irrigation, but also processing and cooling purposes, water is one of the essential resources in both sectors. Rising global population numbers and economic development could likely cause an increase in natural resource demand over the coming decades, while at the same time climate change might lead to lower overall water availability. The result could be an increased competition for water resources mainly in water-stressed regions of the world in the future. In this study we explore a set of possible changes in consumption patterns in the agricultural and energy sector that could be primarily motivated by other goals than water conservation measures—for example personal health and climate change mitigation targets, and estimate the indirect effect such trends would have on global water requirements until 2050. Looking at five world regions, we investigated three possible changes regarding future food preferences, and two possible changes in future resource preferences for electricity and transport fuels. We find that while an increase in food supply as a result of higher protein demand would lead to an increase in water demand as well, this trend could be counteracted by other potential dietary shifts such as a reduction in grains and sugars. In the energy sector we find that an increasing water demand can be limited through specific resource and technology choices, while a significant growth of first-generation biofuels would lead to a drastic rise in water demand, potentially exceeding the water requirements for food supply. Looking at the two sectors together, we conclude that an overall increase in water demand for both food and energy is not inevitable and that changes in food and energy preferences could indeed lead to an alleviation of water resource use despite rising population numbers., Global Environmental Change, 39, ISSN:0959-3780, ISSN:1872-9495

In a recent article, Trainer argues that electricity from concentrating solar power (CSP) in winter would be unreliable and prohibitively expensive, even if generated in premium desert sites. However, he does not carry out a detailed analysis of the reliability or the cost, but bases his conclusion on five arguments, each of which is either irrelevant or erroneous. In particular, his research question, concerning the cost of a CSP kilowatt-hour during winter is irrelevant, and the answer misleading, because the power station will deliver electricity in summer too. A more relevant and not misleading question would be about the performance – the yearly levelised costs of electricity and the reliability – of a CSP fleet. We argue based on a detailed analysis of the performance of CSP in four deserts worldwide, that a coordinated fleet of CSP stations can indeed provide fully dispatchable electricity, and in some cases even baseload, at low cost.