Controversy and consensus: common ground and best practices for life cycle assessment of emerging technologies

Abstract

The past decade has seen a surge in public and private interest in the application of life cycle assessment (LCA), further accelerated by the emergence of new policies and disclosure practices explicitly mandating LCA. Simultaneously, the magnitude and diversity of stakeholder groups affected by LCA and LCA-based decision making have expanded rapidly. These shifts have brought about a renewed sense of urgency in conducting LCA faster, more accurately, and (often) earlier in the technology development cycle when products and materials can be more easily replaced, modified, or optimized. However, this increased demand for LCA of emerging technologies has revealed several crucial yet unsettled areas of debate regarding best practices for assessing sustainability at early stages of technology development. In this paper, we explore six such controversial topics: (1) appropriate use of LCA, (2) uncertainty assessment, (3) comparison with incumbents, (4) adopting standards, (5) system scale-up, and (6) stakeholder engagement. These topics encompass key issues vigorously debated during a series of workshop-style discussions convened by the LCA of Emerging Technologies Research Network (currently hosted by ACLCA). In this paper, we present the main points of support and opposition for a declarative resolution representing each topic, along with points of consensus, held amongst our research network of LCA practitioners and experts. These debates and associated open questions are intended to build awareness amongst practitioners and decision-makers of the common challenges associated with assessing emerging technologies, while fostering evidence-based and context-informed discussions that are both transparent and impactful for the broader community.