Land-use related environmental indicators for life cycle assessment : analysis of key aspects in land use modelling

Soil is a key environmental compartment, determining the supply of crucial ecosystem services as well as supporting biodiversity below and above ground. In the last 15 years, substantial efforts have been made to incorporate the impacts on land due to production processes - from a life cycle perspective-, in order to improve the comparison of the environmental performance of products. The use of robust models that enable evaluating the effects of land use interventions on soils is critical for obtaining meaningful Life Cycle Assessment (LCA) results. In order to support the recommendations of adequate models, this study: Reviews and compares a set of models for relating land occupation and land transformation to soil indicators at midpoint level, addressing soil properties and functions as well as threats to soil ; Proposes a new land use cause-effect chain to appraise the impacts of land use interventions on soils ; Analyses the characterizations factors provided by the reviewed models The comparison is done through a systematic evaluation, based on the International Life Cycle Data system (ILCD) set of criteria, which considers aspects such as the scientific soundness of the models, their ease of applicability for LCA practitioners, and their level of acceptance by stakeholders. The study is complemented by a supplementary material which contains: the list of the evaluation criteria, the filled-in evaluations and the compilation of characterization factors for the evaluated models that allow for a global application. The supplementary material could be downloaded from http://eplca.jrc.ec.europa.eu/uploads/supplementary-material-land-use.xlsx Based on the results of this evaluation, this study identifies valuable approaches and highlights the strengths and limitations of the reviewed models. Research needs for improving the assessment of land use impact on soil in an LCA context are also identified, namely: 1. adopting a common land use cause-effect chain and land use classification; 2. accounting for different land management practices; 3. assessing the added value of using multi-indicators, as some evaluated models propose, for a comprehensive account of impacts of land use on soils; 4. ensuring consistency from midpoint to endpoint indicators; 5. providing guidance to calculate normalization factors; and 6. ensuring a systematic assessment of models results uncertainty.