Land use impact evaluation in life cycle assessment based on ecosystem thermodynamics Tim Wagendorp, Hubert Gulinck, Pol Coppin, Bart Muys * Laboratory for Forest, Nature and Landscape Research, Katholieke Universiteit Leuven, Vital Decosterstraat 102, B-3000 Leuven, Belgium Abstract Life Cycle Assessment (LCA) studies of products with a major part of their life cycle in biological production systems (i.e. forestry and agriculture) are often incomplete because the assessment of the land use impact is not operational. Most method proposals include the quality of the land in a descriptive way using rank scores for an arbitrarily selected set of indicators. This paper first offers a theoretical framework for the selection of suitable indicators for land use impact assessment, based on ecosystem thermodynamics. According to recent theories on the thermodynamics of open systems, a goal function of ecosystems is to maximize the dissipation of exogenic exergy fluxes by maximizing the internal exergy storage under form of biomass, biodiversity and complex trophical networks. Human impact may decrease this ecosystem exergy level by simplification, i.e. decreasing biomass and destroying internal complexity. Within this theoretical framework, we then studied possibilities for assessing the land use impact in a more direct way by measuring the ecosystems’ capacity to dissipate solar exergy. Measuring ecosystem thermal characteristics by using remote sensing techniques was considered a promising tool. Once operational, it could offer a quick and cheap alternative to quantify land use impacts in any terrestrial ecosystem of any size. Recommendations are given for further exploration of this method and for its integration into an ISO compatible LCA framework. q 2005 Elsevier Ltd. All rights reserved. 1. Introduction The environmental impact associated with land use is not addressed in many LCA studies [1]. When performing a credible LCA study for products with a major part of their life cycle in a biological Energy 31 (2006) 112–125 www.elsevier.com/locate/energy 0360-5442/$ - see front matter q 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.energy.2005.01.002 * Corresponding author. Tel.: C32 16329726; fax: C32 16329760. E-mail address: bart.muys@agr.kuleuven.ac.be (B. Muys).