Introducing Microalgae Carbon Fixation and Sinking (MCFS): a new approach for controlled and scalable CDR

Achieving global climate targets requires scalable and durable carbon dioxide removal (CDR) technologies to tackle both historical and hard-to- abate emissions. We introduce Microalgae Carbon Fixation and Sinking (MCFS), a marine CDR methodology designed to enhance carbon fixation and export to the deep ocean through a controlled process. At the core of the MCFS approach is a tailored substrate: a non-toxic organic and / or inorganic structure containing bound stable micronutrients that promotes local phytoplankton growth within it. It is designed for a dual-phase lifecycle: a fixation phase, allowing a sufficiently long duration of floating to maximize biomass accumulation (up to 30 days), followed by rapid sinking, which minimizes remineralization in the water column (hours- days to reach seabed). The MCFS methodology operates within a governance framework that includes site selection of physically and biochemically advantageous regions that ensure carbon sequestration durability of hundreds to thousands of years. To address potential ecological risks a threshold-based approach is adapted, consisting of detailed activity design and pulsed deployments. Monitoring protocols are applied before, during and after each activity. MCFS offers a controlled and scalable pathway to harness the ocean's sequestration capacity while maintaining the activities well within ecological safety and integrity measures.