Weighting in LCA – approaches and applications

Abstract The article deals with the weighting step in Life Cycle Assessment (LCA). Different weighting methods are briefly described, and four operational such methods (Ecoscarcity 97, EDIP, Ecoindicator 99, and EPS 2000d) are applied to a simplified case to illustrate how they can contribute with additional information to the environmental assessment and decision making process. It is argued that the use of weighting can contribute to the relevance and acceptability of LCA results, but that the weighting step should be seen as a test of the compatibility between environmental impact profiles and different value profiles rather than as a procedure leading to a true measure of the aggregated impact. The authors also discuss some issues of controversy connected to weighting, as well as the practical implications of the ISO standard for weighting in LCA.