Applying consequential LCA to support energy policy: land use change effects of bioenergy production.

Luxembourg aims at complying with the EU objective of attaining a 14% use of bioenergy in the national grid by 2020. The increase of biomethane production from energy crops could be a valuable option in achieving this objective. However, the overall environmental benefit of such option is yet to be proven. Consequential Life Cycle Assessment (CLCA) has shown to be a useful tool to evaluate the environmental suitability of future energy scenarios and policies. The objective of this study was, therefore, to evaluate the environmental consequences of modifying the Luxembourgish agricultural system to increase maize production for biomethane generation. A total of 10 different scenarios were modelled using a partial equilibrium (PE) model to identify changes in land cultivation based on farmers' revenue maximisation, which were then compared to the baseline scenario, i.e. the state of the agricultural sector in 2009. The results were divided into three different consequential decision contexts, presenting differing patterns in terms of land use changes (LUCs) but with minor shifts in environmental impacts. Nevertheless, energy from maize production would imply substantially higher environmental impacts when compared with the current use of natural gas, mainly due to increases in climate change and agricultural land occupation impacts. The results are discussed based on the consequences they may generate on the bioenergy policy, the management of arable land, the changes in import-export flows in Luxembourg and LUCs in the domestic agricultural system. In addition, the specific PE+LCA method presented intends to be of use for other regional studies in which a high level of site-specific data is available.