circular food system_ kringlooplandbouw


What should I eat? What’s good for me, for our climate, for our natural world, for our planet? Will animals still play a role in our future food supply; do we all have to become vegan?

The impact of food production

We know that the way we currently produce food has a negative impact on our global environment. Best known is the release of greenhouse gases associated with food production; it is the source of 25% of all greenhouse gases released as a result of human actions. Food production furthermore is largely responsible for Brazil’s deforestation, with the associated loss of tropical rain forest biodiversity. It pollutes both fresh and sea water, and uses 40% of all the land worldwide not covered by ice or desert. Moreover, we are extremely concerned about issues like the size and profitability of farms, animal welfare, the risks of animal-borne diseases, and the public health impact of eating processed food.

Environmental impact of livestock farming

Livestock farming has the greatest impact on the environment of all the food we produce. Converting forest to agricultural land for animal feed production is one of the main sources of CO2 emissions, but let’s not forget methane (CH4) emission from ruminants and from manure storage.

Livestock farming also causes the degradation and erosion of large areas of grasslands, mainly through overgrazing. But it also contributes to the increasing scarcity and pollution of water, through excessive irrigation, pesticide use, and fertilizer leaching from land. Moreover, the expansion of agricultural land and deforestation is decimating global biodiversity. Together, there are plenty of reasons for people questioning whether they should continue to use products of livestock farming: are they really sustainable


Obviously, we have to do things differently in the future, but how? Let’s look at the prospects. We know that the world’s population will grow from the current 7.7 billion to about 9.7 billion in 2050. Global prosperity is also expected to increase, and without any interventions, we expect the demand for animal products to grow accordingly. This scenario would result in a huge increase in land required for both the world’s expanding herd and its feed production, with an associated increase in livestock farming’s other negative effects. While, at the same time in our fight against climate change, we need to reforest much more land for biodiversity and use land to grow crops for biofuels. But most of all, we can hear and feel nature’s cry for help: we need to damn the current wave of extinction.

But let’s not forget, at the same time our cities are rapidly expanding to house this massive population growth. It’s going to be really difficult to manage this balance in many regions. The problems are greatest in Africa, South Asia, and the Middle East where we see a combination of rapid population growth, desertification, low crop yields, and general water scarcity. Deforestation in Brazil is currently well publicized, but we expect rainforests in the Democratic Republic of Congo and other regions to be decimated, as well as seeing vast tracts of savanna converted into agricultural land. The problem is truly global: it extends from Brazil, India and even includes Australia.

So we need to ensure that agriculture becomes more sustainable. The question is how?

We set up this project to investigate whether and, if yes, how a transition to a circular food system can provide a solution to many of these issues.

A circular food system

In a circular food system, we want to produce enough healthy food for the growing world population while taking our planet’s carrying capacity into account. This has many consequences: it means that we don’t want to convert nature into arable land, as this negatively affects both our climate and global biodiversity. To achieve this, we need to make optimum use of all our biomass. We can prevent losses by using the residues from one chain as raw materials for another. Residual products consist of losses arising from food production and consumption, such as crop residues, by-products from industrial food processing, waste, and human and animal excrement. If we take bread as an example, residues from harvesting are straw and chaff, wheat bran is a flour production residue, and general waste and human faeces are by-products of consumption.

Thus, from an environmental point of view, we need to avoid losses throughout the complete chain - from production to consumption. This means that we ask critical questions like, “Is over-consumption of meat, for example, not a waste because more food is produced than is actually needed?”, or “Do we still have to produce crops that do not directly contribute to our daily nutrient need?”. These questions are currently viewed as being controversial, and the answers depend on many socio-economic aspects. Producing a food system without losses may not be possible, but we can strive to minimise losses and make optimal use of any residual products.

Animals in a circular food system

So, the idea is to reuse residual products where possible, by converting them into valuable animal feed, or into fertilizer, for example. Pigs are omnivores and can convert many forms of waste into meat and manure. On grasslands, cows or other ruminants, graze, thereby producing milk, meat and manure. In this system, the number of livestock is generally limited by the amount of grass feed and residual flows. In an ideal circular system, production - and therefore livestock - should result from an optimal processing of the available residual products, whereby the sum of all products meets human nutritional needs. By feeding only residual products and grass to animals, we can currently produce about a third of our daily required protein intake. However, we need differing food products to meet our nutritional needs at different stages of our life-cycle, our health, and our activity. So at some stages, in addition to digestible proteins, we may need to add dairy products for essential calcium, and oily fish products for omega-3 fatty acids, etc. In general, this means that depending on socio-economic factors, consumption patterns will vary. In areas of economic well-being, people should start to consume less animal products, while in low-income countries, animal product consumption may be higher.

Moreover, by feeding animals with waste products only, we would significantly reduce the current area of scarce arable land needed for our current diet. Our use of arable land would then also be lower in this circular system than it would be when producing for a completely vegan diet, because residual flows in that system would not be converted and are therefore lost. In contrast to production of animal products using these residual flows. However, this leaves many questions like, “What is the effect on greenhouse gases emissions/ on biodiversity/ on phosphate and nitrogen cycles/ on water use?” These are the questions we would like to answer in this project.

Our project

To achieve a circular agricultural system as described above, we need a transition in which arable and animal production chains are ingenuously tied together. In our study, we use a model to provide insights into what a future circular food system should look like. We will answer questions such as, “Which crops should we produce where?”, “Which and how many animals are needed?”, “On what scale should we close cycles?”, “What will our diet look like?”, “How does it differ around the world?”, and “How quickly are we reaching our planet’s boundaries?”. Answers to these essential questions are needed if we want to produce a healthy diet for everyone.

Towards a circular food system

But we want to achieve even more. We also want to investigate how we can initiate a transition to a circular food system. Our findings will enable us to sketch an image of a future, but how do we get from where we are now to that ideal future? That's something we’ll have to do together! To be able to do this, we have to account for socio-economic aspects in order to predict which changes are realistic, and what can be done when. This is something that we will explore together with different stakeholders.

This can only be done on a local scale, as socio-economic differences are crucial. In some parts of the world, such as Africa and Asia, it may be possible to increase the input of insects in the food system, while this would be unrealistic in the short term in Europe. Our aim is to find those innovations that trigger a positive transition towards circularity. We will create a roadmap for companies, policy analysts, and consumers in order to ensure that we move towards that dot on the horizon: a world in which people are able to consume healthy diets produced with respect for our planet.