Hannah van Zanten is associate professor at the institute for Farming Systems Ecology at the Wageningen University. Her research focuses on optimising the use of biomass by way of developing and introducing circular agrofood systems. AVINA supports Hannah van Zanten in developing a globally applicable model that calculates the optimal circular agricultural use of an area based on a given diet.
Hannah van Zanten
In her research project, Hannah van Zanten tackles a hugely complex and ambitious topic. In our interview, Hannah provides us with a glimpse into her work, describes her target audience and talks about follow-up research.
In five sentences, or less, describe the project.
It is widely recognised that we need to transform the food system to avoid exceeding the Earth’s biophysical limit. Our project aims to take us closer to new ways of feeding the world’s population, while safeguarding the planet. While the principles of circularity make sense scientifically and are currently trending, we do not really know to what extent a circular food system can reduce the pressure on the Earth’s system. Our goal is to compile a model that produces a blueprint for a circular food system based on a number of different variables.
Can you describe the model in more detail? What are the components and variables your model uses in order to create a circular food system?
In technical terms, the Circular Food System model (CiFoS) is a bio-physical food system optimisation model coded in GAMS that embraces circularity principles by nature due to its unique model structure.
Think of it like this: You take geographic as well as climatic data (arable land, grassland & fisheries, rainfall, climate etc.) as the base of the calculation, enhance it with dietary requirements of the population and the model produces a template for the optimal use of the available agricultural areas in order to provide the food required for the population’s diet.
CiFoS facilitates the choice of food system configurations that minimise a selected environmental impact (e.g. land use or GHG emissions). That is to say, that the system operates within the planetary boundaries that nature has given us. These consist of greenhouse gas emissions, land use, water use, nitrogen and phosphorus supply and biodiversity.
We are well aware that the change to a circular food system cannot happen overnight, which is why we are working with time scenarios (e.g. 2030-2050) in order to gradually shift the production system, waste recycling and diet toward circular patterns.
The model can be scaled depending on the requirements. It uses a country-level aggregation with a bottom-up approach but can be applied up to a global scale. Optimisation can be performed at a country level, assuming ‘a closed system’ or an ‘open system’, which allows for the trade of agricultural commodities. To meet the daily WHO recommended nutrient requirement, the model will select a combination of food items from plants, farm animals, or captured fish that minimises land use or GHG emissions. The components can hence be broken down into plant-based food, animal-sources food and captured fish.
Plant-sourced food: The type and amount of plant-based food in the diet is determined by optimal crop rotations, including yields of possible rotations in all the ecoregions in the world. The final choice of exact crop rotation is determined by its potential to feed humans (i.e. combination of crop yields and their nutritional quality for humans), and the potential of associated crop-residues and co-products to feed farm animals or to fertilise soil.
Animal-sourced food: The amount of animal-sourced food produced by diverse systems depends on the quantity and quality of leftovers and grass resources available for farm animals, the capacity of these animals to convert these biomass streams into animal-sourced food and the nutritional value of animal-sourced food.
Captured fish: In addition to farmed fish, captured fish account for a fixed amount of fish meat for human consumption and fish oil and meals available as a feed source as defined by the Sustainable Maximum Yield.
I spent the rest of my PhD developing a vision for a circular food system, revolutionary in the sense that, against current trends, it included a role for animals to achieve optimal nutrition with minimal planetary impact.
Aside from including animals, how does your model differ from others?
To come to a paradigm shift, however, consensus among stakeholders about the solutions to reconfigure food systems is required. Stakeholders need to be able to assess the multiple impacts and trade-offs of potential solutions with more certainty to ensure the necessary investments. To design radical reconfigurations of today’s foods system we need optimisation models capable of quantifying this uncertainty. Current global environmental models however ignore the potential to use natural processes and cycles to ensure that waste from one process forms the input to another. In other words, the potential of ecological principles needed to conserve the remaining natural ecosystems (e.g. zero deforestation targets) and regenerate or restore degraded agroecosystems (e.g. regenerate soil health, encourage biodiversity-enhancing practices) within the food system is unexplored terrain. And so the idea was born to developed ‘the Circular Food System model’ (CiFoS). CiFoS is a global bio-physical optimisation model of the food system that meets nutritional needs within planetary boundaries. Using CiFoS, we can design future global and regional food systems that do add up, allowing us to quantify all primary and secondary consequences of change pathways.
When and where was the idea for the project born?
My PhD thesis focused on the potential to avoid feed-food competition in a livestock production system. I started by analysing opportunities for incremental innovations but quickly concluding that the food system required a radical redesign. I spent the rest of my PhD developing a vision for a circular food system, revolutionary in the sense that, against current trends, it included a role for animals to achieve optimal nutrition with minimal planetary impact.
Looking at what the project wants to achieve, one might be overwhelmed by the shear complexity of it. Desmond Tutu famously said that there is only one way to eat an elephant – one bite at a time. What are the metaphorical bites that you chewed off when structuring your approach?
I am deeply committed to contributing to a sustainable world. My affinity for complexity drives me to redesign food systems, integrate knowledge from different domains, and think holistically and creatively. At the same time, I feel the magnitude of the challenge and recognise the importance of connecting with like-minded food system thinkers to create impact. In other words, collaboration and teamwork are key to success. My team is multidisciplinary, diverse and highly motivated. Each of the team members has their own expertise covering for example environmental sciences, crop sciences, human nutrition and animal sciences. Each team member therefore covers one ‘bite’ and by combining all ‘bites’ together we create the CiFoS model! It is my task to coordinate this process, which is a great honour!
What would be the ideal outcome of the project for you?
Where most research focuses on the development of a single solution, our work aims to connect solutions and assess how mutual benefits for both health and environment can be created at different levels within food systems. It will answer questions such as “which crops to grow where”, “which fertilisers to use”, “which animals to keep where”, and “which food to consume”. This is a crucial aspect still missing from existing studies, and it provides new input for the dialogue between science and policy makers, consumer groups and other stakeholders concerned with achieving a more sustainable diet for our growing population while not jeopardising the livelihoods of people and the wellbeing of our planet.
After having created a robust model for a circular food system, who will be the target market for it? Who will be its users?
Stakeholders that need to be able to more accurately assess the multiple impacts and trade-offs of potential solutions to ensure the needed investments respect both human and planetary health. Potential users range from landowners, on the smallest scale, to politicians responsible for implementing agricultural policies of regions, countries or potentially the FAO, World Bank and the United Nations on the largest scale.
What are potential follow-up research topics that can build on your circular model?
Besides a long wish list of additional features, I can add to the model my main focus will be on the use of the CiFoS model by different stakeholders. The CiFoS model has the potential to inform stakeholders beyond this project’s limited timeframe. I therefore aim to translate the mathematical CiFoS model into an iLandLab a so called ‘mixed reality’ (example video). Such an interactive iLandLab tool enables policy makers, industry and practitioners to co-design and evaluate radical yet attainable food systems that respect human and planetary health. In other words the iLandLab tool gives guidance on what to eat and how to produce the food needed to come to a radical redesign of our food system while respecting health and the livelihoods of people. It therefore will help us to accelerate the transitions, to ensure that food systems concepts become day to day reality.
My follow-up research topic is therefore to develop the iLandLab to aid the co-design of possible transitions pathways to circular food systems for multiple case countries that represent a diversity of social-economic contexts. The mixed reality iLandLab will be used to facilitate, structure and document discussions and prioritisations that are needed for the transition.
