Is mCDR pollution? Rethinking pollution for the governance of marine carbon dioxide removal

Marine carbon dioxide removal (mCDR) is increasingly explored as component within the global response to climate change, yet its governance remains fragmented and conceptually unsettled. The London Convention and Protocol (LC/LP) provides a primary institutional home for the international governance of mCDR by regulating certain marine interventions as forms of potential pollution. While this classification is often treated as a technical or legal question, this Perspective argues that how mCDR is understood as pollution has important implications for governance. First, it argues that classifying mCDR as pollution provides an institutional anchor for precautionary oversight within LC/LP. Second, it shows that prevailing technocratic understandings of pollution are insufficient for governing mCDR. Third, it explains why recurring calls for more comprehensive and integrative governance of mCDR can be understood as responses to this conceptual mismatch. Drawing on relational conceptions of pollution, the paper reframes pollution as an activity that reconfigures social-ecological relations. In doing so, it provides a conceptual lens for interpreting ongoing developments in mCDR governance without requiring a departure from existing institutional frameworks.