Developing Life Cycle Sustainability Assessment methodology by applying values-based sustainability weighting - Tested on biomass based and fossil transportation fuels

Abstract

The production and use of transportation fuels can lead to sustainability impacts. Assessing them simultaneously in a holistic way is a challenge. This paper examines methodology for assessing the sustainability performance of products in a more integrated way, including a broad range of social impacts. Life Cycle Sustainability Assessment (LCSA) methodology is applied for this assessment. LSCA often constitutes of the integration of results from social LCA (S-LCA), environmental life cycle assessment (E-LCA) and life cycle costing (LCC). In this study, an S-LCA from an earlier project is extended with a positive social aspect, as well as refined and detailed. E-LCA and LCC results are built from LCA database and literature. Multi Criteria Decision Analysis (MCDA) methodology is applied to integrate the results from the three different assessments into an LCSA. The weighting of key sustainability dimensions in the MCDA is performed in different ways, where the sustainability dimensions are prioritized differently priority based on the assumed values of different stakeholder profiles (Egalitarian, Hierarchist, and Individualist). The developed methodology is tested on selected biomass based and fossil transportation fuels - ethanol produced from Brazilian sugarcane and US corn/maize, and petrol produced from Russian and Nigerian crude oils, where it delineates differences in sustainability performance between products assessed. The outcome in terms of relative ranking of the transportation fuel chains based on sustainability performance differs when applying different decision-maker profiles. This result highlights and supports views that there is no one single answer regarding which of the alternatives that is most sustainable. Rather, it depends strongly upon the worldview and values held by the decision maker. A key conclusion is that sustainability assessments should pay more attention to potential differences in underlying values held by key stakeholders in relevant societal contexts. The LCSA methodology still faces challenges regarding results integration but MCDA in combination with stakeholder profiles appears to be a useful approach to build on further.