Puro.earth has launched a public consultation on a new methodology called Microalgae Carbon Fixation and Sinking (MCFS) Methodology for marine carbon dioxide removal (mCDR).
In the period between 11 June and 2 July 2025, Puro is looking to gather public feedback from stakeholders on this proposed standardization for MCFS CDR activities.
Microalgae Carbon Fixation and Sinking (MCFS) is an approach that captures and sequesters CO2 by boosting the photosynthetic activity of phytoplankton present in the surface ocean and on designated substrates, where the captured carbon then gets exported in an intentional and controlled manner to the deep ocean and ocean sediment.
The methodology put together by Puro presents a global standardized durability of MCFS in the eligible site conditions in 200 years, labeled as COR200+.
Puro.earth clarifies that this 200-year baseline for MCFS activities is founded on an ultra-conservative assumption that all the sunken CO2 is subject to ocean circulation and not sedimented.
With that being said, each MCFS project and its specific ocean conditions can actually unlock a CDR durability of up to several thousand years.
The Puro.earth Microalgae Carbon Fixation and Sinking Methodology covers a number of concrete steps.
These induce the deployment of engineered substrates in ocean regions with high nutrient, low chlorophyll (HNLC) conditions and the growth of additional phytoplankton on the substrate, consuming CO2 dissolved in the ocean and micronutrients that are incorporated in the substrate.
Relevant: Fugro And Ocean Visions Partner On Novel Framework For Responsible mCDR
It also covers the sinking of the substrates and the attached microalgae to the deep ocean, CO2 storage in the slow carbon cycle of the deep ocean, and the re-capturing of consumed CO2 in surface waters, where the carbon captured in microalgae was already dissolved in the surface ocean, and its removal frees up additional ocean carbon uptake capacity.
This methodology also includes vital safeguards to ensure MCFS activities successfully manage social and environmental risks.
To that end, it requires MCFS projects to perform detailed site-specific environmental impact assessments and monitor evaluation data across the different project stages.
Puro.earth is hosting an informative webinar on Wednesday, June 18th, 2025 at 11:00 a.m. Eastern/ 3:00 p.m. UTC, where participants can learn more about this methodology.
Read more: Puro.earth Enables First CORCs Issued In China With Nian’da Biochar Project
