Approaches to incorporate Planetary Boundaries in Life Cycle Assessment: A critical review

The Planetary Boundaries (PBs) pioneering approach defines environmental sustainability in terms of a Safe Operating Space (SOS) for human’s society to develop and thrive. The approach has found fertile ground in combination with Life Cycle Assessment (LCA) - a standardised method for assessing the environmental impacts of product systems. In this article, we conduct a detailed review of existing approaches to embed PBs in LCA. We start by exploring the links between PBs control variables and LCA impact categories and then focus on reviewing three approaches (i) absolute environmental sustainability assessment (AESA), (ii) PBs-based normalisation and (iii) PBs-based weighting. We examine four key methodological aspects covering harmonisation of units (between PBs control variables and LCA indicators), definition and allocation of the SOS, regionalisation of boundaries and temporal aspects. We conclude the review with a discussion on applicability, limitations, policy implications and conclusions.