Global Biosphere Management Model

GLOBIOM is a global, recursive dynamic, linear programming, partial equilibrium model covering the sectors of agriculture, forestry and bioenergy including economic as well as bio-physical aspects. The supply side of the model is built-up from the bottom (spatially explicit land cover, land use, management systems information) to the top (regional markets). Commodity markets and international trade are modelled at the level of aggregate economic regions (the aggregation is flexible and can be adapted to the user needs) where prices are endogenously determined at the regional level to establish a market equilibrium. Trade is modelled following the spatial equilibrium approach representing bilateral trade flows based on cost competitiveness and homogeneous good assumption. Besides primary products for the different sectors, the model has several final and by-products, for which processing activities are defined. The model computes market equilibrium for agricultural and forest products by allocating land use among production activities to maximize the sum of producer and consumer surplus, subject to resource, technological, demand and policy constraints. GLOBIOM captures the multiple interrelationships between different systems involved in production of agricultural and forestry products. For example, population dynamics, changes in socio-economic and technological conditions, ecosystems and climate that lead to adjustments in the product mix and the use of land and other productive resources. The model is calibrated to an average around the year 2000 and solved recursively dynamic, typically done in 10-year time steps, and depending on the study, going up to 2100. The historical period (2000 until the year with most recently available statistics) is usually used as a validation/calibration period of the model.

Economic data is based on the market balances of Eurostat and FAOSTAT. Land cover maps rely on CORINE/PELCOM and GLC 2000. The source of bio-physical crop and forest parameters are the crop model Environmental Policy Integrated Climate Model (EPIC) and the Global Forest Model (G4M), respectively. Price demand elasticities of the USDA are used to model changes in demand in the agricultural sector, forest sector elasticities rely on the scientific literature. Nearly all greenhouse gas emissions from land using sectors and land use change are included and based on Intergovernmental Panel on Climate Change (IPCC) accounting guidelines. Other data (Population, GDP, Technical progress, etc.) were compiled from various databases or models.