Life Cycle Inventory Modelling of Land Use Induced by Crop Consumption Part 1: Conceptual Analysis and Methodological Proposal
The actual land use consequences of crop consumption are not very well reflected in existing life cycle inventories. The state of the art is that such inventories typically include data from crop production in the country in which the crop is produced, and consequently the inventories do not necessarily consider the land ultimately affected in the systems being studied. The aims of this study are to analyse the mechanisms influencing the long-term land use consequences of changes in crop demand and to propose a methodological framework for identifying these consequences within a global scope. The study refers to the principles of consequential LCA, which means that the consequences of changes in consumption are studied from a market-based perspective. In this context, the study addresses the feasibility of using economic modelling to identify ultimate land use consequences of crop consumption. Based on the current market trend for crops and an analysis of basic mechanisms in crop production, concepts for modelling how crop consumption affects the global agricultural area and the intensity of crop production are suggested. It is demonstrated how the assumptions concerning drivers for technological development have a profound influence on identification of the marginal response to crop consumption, and how the geographical location of crop consumption also influences the composition of the marginal production response in terms of cropland expansion and intensification. Crop prices have been falling at a global scale and are projected to decline further. At the same time, crop yields per hectare are continuously increasing. This indicates that drivers other than crop demand have a strong influence on technological development in crop production.Economic modelling in combination with geographical information and agricultural statistics can be used to estimate long-term land use consequences of changes in crop consumption. The GTAP Model is a suitable tool although it requires implementation of land supply curves, adjustment of elasticities to reflect long-term changes, and possibly establishment of a link between crop demand and technological development. Through this approach, life cycle inventories for crops reflecting the actual land use consequences of consumption can be established. Further work (based on the methodological framework in this study) will address the practical modelling of land use changes induced by crop consumption in different regions with the purpose of including this in LCI.