The evolution of “phase-out” as a bridging concept for sustainability: From pollution to climate change

Many sustainability challenges, such as contamination of air, water, and soil or climate change, can be traced back to specific polluting substances (e.g., mercury), technologies (e.g., combustion engines), or practices (e.g., waste dumping). To confront these grave challenges, “phase-out” is garnering increasing attention as a policy approach. Although the literature on phase-out is burgeoning, it remains unclear how the concept has evolved across scientific disciplines and policy. In this review, we use a coding-based mapping approach to systematically unpack the scientific discourse on phase-out since 1970, focusing on the contribution of different scientific disciplines, targets and drivers of phase-outs, instruments, affected industries, and geographical context. We find that the focus of phase-out has shifted from toxic pollution to climate change, and that the scope of phase-out targets has broadened. Results further suggest that phase-out is emerging as a bridging concept to foster transdisciplinary dialogues and transformative actions toward greater sustainability.