Agrifood system modelling and scenarios for biodiversity TC4BE Deliverable 1.1
Creators: name: Institute for Sustainable Development and International Relations
name: Centre de Coopération Internationale en Recherche Agronomique pour le Développement
name: Wageningen University & Research
name: Prudhomme, Rémi
name: Ruillé, Marie
name: Dumas, Patrice
name: Aubert, Pierre-Marie
Publisher: name: Zenodo
Year: 2024

description: Intent and method of the deliverable

The aim of this report is to present a modelling framework aimed at factoring in biodiversity thresholds on a global scale using a biomass-balance model of the world food system called BIODIVA. This framework relies on the identification of six biodiversity proxies and their associated thresholds, presented in a peer-reviewed paper (García-Vega et al. 2024): the total agricultural area, the pesticide pollution, the nitrogen (N) balance at a watershed level, share of semi natural vegetation in agricultural landscapes, cropping systems (intercropping and crop rotation), and management of grasslands. For each proxy, a computation method is proposed to identify the type of agricultural systems that would comply with each threshold. A systemic approach is then proposed to combine all proxies and identify the boundaries of a food system that would respect all thresholds. To reflect several proxies and their associated thresholds (N management, grassland management, semi natural vegetation and their implication for e.g. crop yields), BIODIVA combines three levels of spatial analysis: (i) a fine scale at the grid point, to consider certain surface and production constraints (the scale used here corresponds to a degree of resolution of 0.5x0.5, corresponding to the scale of the MAPSPAM data); (ii) a watershed level, which corresponds to an aggregation of the finer scale mentioned above for over 25,000 watersheds across the world; and (iii) an aggregation of world regions (large countries and aggregations of countries), for the following regions: Asia (excluding India and China), Brazil, China, Europe, Former Soviet Union, India, Latin America (excluding Brazil), Middle East and North Africa, and Sub-Saharan Africa.

Results 

The first results obtained show that the level of N-constraint is extremely important. In several of the BIODIVA areas (China, the European Union, Middle East and Northern Africa), the available “space” for nitrogen application on cropland if we were to respect N thresholds would be negative, account being taken of other N sources (re-deposition, urban areas / sewage treatment, natural ecosystems). As such, it is the main determinant of total crop production in most regions considered in the model. Under the current simulation / set of assumptions, no more than 1/3 of the cereals needed to feed the expected 2050 world population a healthy diet could be produced.

Regarding animal production, things are more contrasted. Under the very ambitious assumption that all food waste and losses could be recycled and fed to monogastric animals (pork and poultry), monogastric meat production could exceed the demand. Ruminant production (milk and meat) would only meet respectively 60 and 40 % of demand.

Implications for project

More analysis is needed to identify if, and how, the N constraint can be partly lifted, and where. This will have critical implications to design a world food system that works for food security, biodiversity and climate. Scenario exercises at the landscape level to be carried out in WP5 will also benefit from these analysis. It is worth noting that BIODIVA cannot be downscaled to a landscape level and only aims to provide relevant results at a broad world region level.

Finally, the social / equity dimension has not yet been considered. This will be done in the future deliverable focusing on Europe and looking in particular at the cost of the transition.

Implications for policymakers /TC in agrifood systems 

There are no implications for policy makers as the results presented here are still very preliminary.