A review of monetary valuation in life cycle assessment: State of the art and future needs

Monetary valuation is used in Life Cycle Assessment (LCA) to aggregate environmental impacts expressed with different units of measure and therefore not directly comparable, in order to facilitate the communication and the use of LCA results in decision-making processes. Although several authors have discussed the advantages of using monetary valuation in the weighting phase of LCA, its practical implementation is still challenging. The aim of this study is to critically assess the available monetary valuation approaches applicable in LCA and highlight challenges and research needs towards the development of a set of monetary valuation factors to be applied to life cycle impact assessment methods, e.g., the European Environmental Footprint one. To this end, a literature review was performed to collect and compare monetary valuation coefficients. The review highlighted significant variability in the availability of monetary valuation coefficients across impact categories, with some (e.g., climate change) commonly analyzed, compared to others (e.g., terrestrial euthrophication) with very little information available to date. The collected monetary valuation coefficients were tested in a case study on the environmental impacts of the consumption of an average European citizen. Results were compared with the per capita household expenditure as a point of reference, yielding a contribution of the external damage ranging from 15% to 41% of the per capita expenditure. The novelty of this work lies in performing an updated and systematic assessment of the available monetary valuation approaches for LCA and investigating the variability of the results that stem from the adoption of different approaches, paving the way towards an increased use of LCA and environmental considerations in decision making processes.