Expert Workshop on Land Use Impacts in Life Cycle Assessment. 12–13 June 2006 Guildford, Surrey (UK)

Goal, Scope and Background. On June 12–13 June 2006 in Guildford (UK) an international workshop was held to address indicators to incorporate land use impacts in LCA. It provided an interdisciplinary forum where soil scientists and biologists met with LCA experts and users to discuss the challenges of including land use impacts in LCA and potential approaches to addressing these challenges. The discussion used as starting point the definitions framed in the past work on land use impacts within the UNEP/SETAC Life Cycle Initiative (Milà i Canals et al. 2006). However, the presence of soil quality and biodiversity experts allowed for a more in-depth consideration of the nature of land use impacts. Main Features. The discussions were focused on three main themes: general methodological issues to be addressed in including land use impacts in LCA; recommendations for soil quality indicators; and recommendations for biodiversity indicators. Results and Discussion. There is a conflict between the levels of detail at which LCA should assess land use impacts: a coarse assessment may allow the detection of hotspots from a life cycle perspective, whereas a more detailed assessment might allow the distinction between land management modes (e.g. organic vs. conventional agriculture). Different land use processes need to be modelled in consequential and attributional LCA. Land use effects on biodiversity and soil quality are non-linear and also depend on the scale of land use, which is difficult to address in LCA. Soil is multi-functional and many threats affect its quality, which results in a case-specific selection of the most adequate indicator. In the case of biodiversity, two main options for defining indicators were identified at species and ecosystem levels. The main advantage of the former is data availability, but the election of a particular taxon may be arbitrary. Ecosystem level indicators include a higher degree of subjectivity but may be more relevant than species level ones. Conclusions. Land use impacts need to be considered in LCA for all life cycle stages in all types of products. An urgent need for LCA is to incorporate land use impacts particularly in comparisons of systems which differ substantially in terms of land use impacts. The main differences between consequential and attributional LCA are the need for the consideration of off-site effects and marginal vs. average land uses in consequential LCA. In order to define the marginal effects of land use a similar approach to the description of the electricity grid and its marginal technology may be followed. ‘Dose-response’ functions need to be defined for land use interventions and their effects. The main soil degradation processes (considering soil’s vulnerability to different threats) should be captured in a spatial-dependent way in LCA. Criteria and examples to select biodiversity indicators at species and ecosystem levels were proposed in the workshop. Recommendations and Perspectives. The conduction of LCA case studies for relevant systems (especially fossil energy compared to bio-energy systems involving different eco-regions to account for potential international trade) may provide a good platform to further develop the workshop suggestions.