Using the planetary boundaries framework for setting impact-reduction targets in LCA contexts

The planetary boundaries (PBs) framework suggests global limits for environmental interventions which could be used to set global goals for reducing environmental impacts. This paper proposes a procedure for using such global goals for setting impact-reduction targets at the scale of products for use, for example, in life cycle assessment (LCA) contexts, e.g. as a basis for evaluating the potential of interventions to reduce the environmental impact of products. The procedure consists of four steps: (i) identifying the PBs quantified in literature that correspond to an impact category which is studied in the product assessment context in question; (ii) interpreting what the identified PBs imply in terms of global impact-reduction targets; (iii) translating the outcome of (ii) to reduction targets for the particular global market segment to which the studied product belongs; and (iv) translating the outcome of (iii) to reduction targets for the studied product. The procedure requires some assumptions and value-based choices-the influence of these is tested by applying the procedure in a specific LCA context: a study of Swedish clothing consumption. The application of the procedure in an LCA context suggested the need for eliminating all or nearly all impact of Swedish clothing consumption for most impact categories. Thus, it is improbable that a single type of impact-reduction intervention (e.g. technological development or changed user behaviour) is sufficient. The outcome's strong dependence on impact category suggests that the procedure can help in prioritising among impact categories. Furthermore, the outcome exhibited a strong dependence on the chosen method for allocating the globally allowed impact between regions-this was tested by applying different principles identified in a literature review on the allocation of emissions rights. The outcome also strongly depended on the geographical scope-this was tested by changing the geographical scope from Sweden to Nigeria. The proposed procedure is feasible to use for LCA practitioners and other environmental analysts, and data is available to apply the procedure in contexts with different geographical scopes. Value-based choices are, however, unavoidable and significantly influence the outcome, which accentuates the subjectivity and potentially controversial nature of allocating a finite impact space to certain regions, market segments and products. How to match PBs with appropriate LCA impact categories is an important area for future research.