On the meaning of the distance-to-target weighting method and normalisation in life cycle impact assessment

Distance-to-target weighting methods are widely used in life cycle impact a ssessment. The methods rank impacts as being more important the further awa y society's activities are from achieving the desired targets for the pollu tants. However, we feet that the scientific bases of the distance-to-target methods still need more clarification. This article illustrates how multia ttribute value theory (MAVT) can be applied to interpret the impact categor y weights as well as the aggregation rule and normalisation used in the dis tant-to-target methods. Our comparison revealed that under certain conditio ns two of the three commonly used impact assessment methods (Ecoindicator 9 5, ET-method) applying distance-to-target weighting are consistent with the impact assessment framework derived from MAVT. This consistency holds for non-zero targets with equal importance and linear damage functions passing through the origin. We show that the MAVT framework offers a foundation for the methodological development in life cycle impact assessment.