Life cycle sustainability assessment: What is it and what are its challenges?

Abstract

Environmental life cycle assessment (LCA) has developed fast over the last three decades. Today, LCA is widely applied and used as a tool for supporting policies and performance-based regulation, notably concerning bioenergy. Over the past decade, LCA has broadened to also include life cycle costing (LCC) and social LCA (SLCA), drawing on the three-pillar or ‘triple bottom line’ model of sustainability. With these developments, LCA has broadened from merely environmental assessment to a more comprehensive life cycle sustainability assessment (LCSA). LCSA has received increasing attention over the past years, while at the same time, its meaning and contents are not always sufficiently clear. In this chapter, we therefore addressed the question: what are LCSA practitioners actually doing in practice? We distinguished two sub-questions: which definition(s) do they adopt and what challenges do they face? To answer these questions, LCSA research published over the past half decade has been analysed, supplemented by a brief questionnaire to researchers and practitioners. This analysis revealed two main definitions of LCSA. Based on these two definitions, we distinguished three dimensions along which LCSA is expanding when compared to environmental LCA: (1) broadening of impacts, LCSA = LCA + LCC + SLCA; (2) broadening level of analysis, product-, sector- and economy-wide questions and analyses; and (3) deepening, including other than just technological relations, such as physical, economic and behavioural relations. From this analysis, it is clear that the vast majority of LCSA research so far has focused on the ‘broadening of impacts’ dimension. The challenges most frequently cited concern the need for more practical examples of LCSA, efficient ways of communicating LCSA results and the need for more data and methods particularly for SLCA indicators and comprehensive uncertainty assessment. We conclude that the three most crucial challenges to be addressed first are developing quantitative and practical indicators for SLCA, life cycle-based approaches to evaluate scenarios for sustainable futures and practical ways to deal with uncertainties and rebound effects.