The Puro.earth Advisory Board has greenlighted the methodology for Microalgae Carbon Fixation and Sinking (MCFS), creating a new safe and science-backed pathway for harnessing the ocean’s CO2 absorbing capacity to mitigate climate change.
The approval comes four months after the proposed Puro.earth MCFS methodology entered a period of public consultation, during which Puro.earth received more than 100 comments from different field entities.
Created through extensive scientific consultation, stakeholder feedback, and internal review, the methodology needed a final Advisory Board approval, which has now been granted, confirming that all of its components are scientifically credible, environmentally responsible, and grounded in real-world feasibility.
This is the third ocean-based carbon removal methodology to be approved by Puro.earth, following the official introduction of the Marine Anoxic Carbon Storage (MACS) and Direct Air Capture and Ocean Storage (DACOS) methodologies earlier this year.
The process of carbon removal via MCFS refers to a procedure in which custom-designed engineered substrates are placed in the top ocean layers, where they foster local CO2-absorbing microalgae (phytoplankton) growth.
Once the microalgae have colonized, after a predetermined, substrate-specific amount of time, the substrate and phytoplankton are sunk into the deep ocean layers at a rapid speed, where the CO2 captured in the microalgae will remain stored for centuries.
This approach is not to be confused with ocean fertilization, which disperses nutrients freely into surface ocean layers, often resulting in ecologically threatening uncontrolled algal blooms.
To preserve the eco balance and effectively remove atmospheric CO2, the MCFS approach ensures that the nutrients remain bound in the substrate, with the algae growing directly on the substrate, and the swift and controlled sinking exports the carbon-dense algae to deeper ocean layers within a maximum of 30 days.
Relevant: Puro.earth Starts Public Consultation On New Microalgae CO2 Fixation & Sinking Methodology
The MCFS methodology outlines strict requirements, including a scale limit of a maximum of 1 MtCO2 per facility and a speed of >20 m/hour for sinking the substrate and microalgae within the 30-day timeframe.
Additionally, it comes with strict threshold criteria and elaborate pre- and post-deployment monitoring and a quantification that combines direct measurements and model outputs.
This microalgae carbon fixation and sinking methodology also lays out clear site eligibility rules, demanding high nutrient, low chlorophyll (HNLC) regions within EESs and in places where deep waters grant at least 200 or more years of carbon storage.
Read more: Southwire And Algae Tree Deploy A Pilot Microalgae-Powered CDR Unit In Georgia
