Burying Carbon at Sea: Is mCDR a Real Solution, or a New Kind of Hope-Peddling?
For the past few years, a concept has been drifting from the margins of climate discussions toward the center: **marine Carbon Dioxide Removal**, or **mCDR**. Investment is growing fast; "ocean carbon credits," which numbered only a few thousand a year not long ago, topped 340,000 last year. Major companies like Microsoft are pre-ordering hundreds of thousands of credits for trials whose results are not yet known. It sounds appealing: the ocean already absorbs carbon from the atmosphere, so what do we lose by "speeding up" that process a little? The answer is far more complicated than it seems. This piece draws on three sources: the Ocean & Climate Platform's policy brief published in June 2026 ("Navigating Hopes and Threats"), the underlying npj Ocean Sustainability perspective article signed by nearly thirty scientists ("Three Challenges to Marine Carbon Dioxide Removal"), and the Stockholm Resilience Centre's coverage that brought ...