GlobAgri database and model
The GlobAgri platform has been set up by CIRAD and INRAE to generate consistent databases and biomass balance models using data from FAOStat as well as data shared by colleagues from different institutions 1. The databases are balanced and account for the links between products (through animal feed or oilseed crushing for instance). Biomass balance models provide equilibrium between resources (domestic production plus imports minus exports) and utilization (food, feed, other) for each region and each agri-food product. For each agri-food product, imports are a linear function of domestic total uses and exports are a linear function of the world market size. To preserve the global coherence in the model, two constraints are introduced: the first one ensures that at the world level, for each agri-food product the sum of all imports equals the sum of all exports; the second one imposes a maximum cultivable land area for each region that cannot be surpassed. The system of balance equations can simulate land-use change in each region induced by changes in the uses of agri-food products, provided hypotheses on changes of a set of variables (such as plant and animal yields, maximum available cultivable land, trade conditions, etc.). The GlobAgri platform has been used to generate databases and biomass balance models specifically customized for various studies (specific product and country aggregation, specific rules of co-product handling, specific rules of model closure). This website aims at reporting these studies in order to illustrate GlobAgri’s potential.
The modelling framework is summarised in the figure below, extracted from Forslund et al. (2023).
Specification and functioning of biomass balance models generated from GlobAgri
Source: Forslund et al. (2023). Can healthy diets be achieved world wide in 2050 without farmland expansion. Global Food Security, 100711.
Let’s suppose that the scenario to be simulated involves a change in the food diet and in agricultural production systems in one region. This would translate into a change in the food consumption levels of agri-food products as well as in crop yield and livestock productivity levels relative to the initial situation in the considered region. The levels of imports, exports, and domestic production would then adjust to restore equilibrium between resource availability and resource use. As imports of the considered region are produced abroad while exports replace production abroad, balances in other regions are adjusting as well. Therefore, land area needs change in all regions.
When no region reaches its maximum cultivable area, adjustments stop and a new global equilibrium is achieved. In that case, import coefficients and export shares remain exogenous.
When one or some regions need more cultivated area than their maximum cultivable area, additional adjustments are required to restore equilibrium. In regions where the limit on cultivable land area is reached, equilibrium is achieved by reducing exports (via a decrease in the region’s export shares) and/or increasing imports (via an increase in import coefficients). More specifically, for a region exceeding its maximum cultivable land area, export shares are decreased equi-proportionnally for all products. If even with zero exports, the region still needs more cultivated area than its maximum cultivable area, then the region starts increasing its imports (through increases in import coefficients). In other words, the region increases the share of its food needs which is covered by imports in order to reduce the required rise in domestic production and save some cultivated area.
As initial import coefficients of regions vary widely across products, we defined intervals of initial levels upon which the coefficients are increased evenly, allowing for differentiating the level of increase by band.
The GlobAgri database and model are fully described in Le Mouël et al. (2018) and Mora et al. (2020) (cf. Resources).
1 – These colleagues are warmly thanked as well as their institutions: Center for Sustainability and the Global Environment (SAGE), Commonwealth Scientific and Industrial Research Organisation (CSIRO), International Institute for Applied Systems Analysis (IIASA), Institute of Soil Science of the Chinese Academy of Sciences, Joint Research Centre (JRC), Princeton University, World Fish Institute, World Resources Institute (WRI) and Woodrow Wilson School of Public and International Affairs.