Promoting low-carbon innovation has long been a central preoccupation within both the practice and theory of climate change mitigation. However, deep lock-ins indicate that existing carbon-intensive systems will not be displaced or reconfigured by innovation alone. A growing number of studies and practical initiatives suggest that mitigation efforts will need to engage with the deliberate decline of carbon-intensive systems and their components (e.g., technologies and practices). Yet, despite this realisation, the role of intentional decline in decarbonization remains poorly understood and the literature in this area continues to be dispersed among different bodies of research and disciplines. In response, this article structures the fragmented strands of research engaging with purposive decline, interrogating the role it may play in decarbonization. It does so by systematically surveying concepts with particular relevance for intentional decline, focusing on phase-out, divestment, and destabilization.