Marine carbon dioxide removal (mCDR) is getting more attention as a possible way to close the gap between emissions cuts and climate goals. EDF explains three approaches under discussion: ocean alkalinity enhancement, ocean fertilization, and biomass sinking. It also notes that none of these methods have yet proven they can work safely, affordably, or at scale. The article covers recent decisions at the London Convention and London Protocol, where governments adopted assessment frameworks for mCDR research. Those frameworks create a common process for evaluating environmental risks, public consultation, and monitoring. They do not approve commercial deployment. EDF also connects mCDR to the ocean twilight zone, the mesopelagic layer that already moves 2 to 6 gigatons of carbon per year. The takeaway is that research into ocean carbon removal needs strong guardrails and community input before any method can be considered viable.
