McKinsey review: Ocean carbon dioxide removal prospects

McKinsey has published an analysis highlighting the role and potential of ocean carbon dioxide removal (ocean CDR) and calls for urgent, coordinated R&D, regulatory, philanthropic, and industry action to build a foundational ocean CDR ecosystem over the next decade.

• Main announcement and findings: The report outlines five major ocean CDR approaches (coastal ecosystem restoration; direct ocean capture (DOC); ocean alkalinity enhancement (OAE); algae cultivation and harvesting; open-ocean microalgae fertilization), estimates the ocean could support more than ten gigatons of annual CO2 removals, and notes pilot DOC costs of $900 to $3,000 per ton. It highlights high efficiency and high scaling potential but warns of scientific uncertainty and ecological risks that require R&D and robust methodologies.
• Background, evidence, and specific details: Authors include Emma Parry, Mark Patel, Gualtiero Jaeger, Jonathan Scott, and Shruti Badri (McKinsey offices: London, Bay Area, Nairobi). The report cites bodies such as the IPCC, London Convention and London Protocol (which flagged possible “deleterious effects that are widespread, long-lasting, or severe” for some approaches), and research collaborators including CarbonPlan and [C]Worthy. It calls for shared research results, regulatory frameworks, Indigenous and community engagement, and stakeholder funding to derisk and scale ocean CDR within the next decade.