CDR.fyi Durable CDR Methods Update | June 2025

At CDR.fyi, our mission is to provide transparency in the carbon dioxide removal (CDR) ecosystem, helping to accelerate the development of a durable CDR market globally. The biggest challenge facing the industry is slow buyer engagement beyond the early leaders in the space. One of the key challenges prospective purchasers face is a lack of clarity on the methods of durable carbon removal.

To ensure we remain aligned with the latest industry developments and reporting on the industry’s progress in a way that is clear to prospective buyers and other industry participants, we are updating our durable CDR method classification system. This update reflects the evolving landscape of CDR technologies, increasing the clarity of our reporting for prospective purchasers while retaining the detail expected by more sophisticated purchasers.

Why the Update?

The field of carbon dioxide removal is rapidly advancing, with new methods emerging and existing ones evolving. We believe that over 99% of the long-term buyers of durable CDR have not yet entered the market. They are hindered by several factors, one of which is the multitude of durable CDR methods available to them. Conversely, many suppliers seek to name their method uniquely for competitive differentiation, but the vast array of naming conventions leads to buyer confusion, and reduces the likelihood those methods will appear in market reporting due to their low volumes.

Our goal is to deliver transparency and clarity. Our refined classification system aligns with the current state of the industry, enabling us to deliver a clear view of method development across categories for prospective buyers and in our reporting, while continuing to enable suppliers to share the detailed attributes of their methods that are of interest to more sophisticated buyers. These changes make it easier for stakeholders to navigate the complexities of durable carbon removal and take informed action toward climate goals.

The Updated List of Durable CDR Methods

Below, we provide the updated list of methods we track, along with a brief description of each. Where changes have been made, we’ve explained the reasoning behind them.

The Methods displayed in the table above will be used for data classification, while the Category will be used for reporting to reflect the availability of data for display.

[Image by Third Way]

Biomass Carbon Removal and Storage (BiCRS)

Bioenergy with Carbon Capture and Sequestration (BECCS) | *CHANGED*

Combines biomass energy production with carbon capture and storage technologies. CO₂ released during biomass combustion or fermentation is captured and permanently stored, creating net-negative emissions. The word “Storage” has been updated to “Sequestration” in the title, given that the captured emissions are generally liquefied and stored geologically.

Biochar Carbon Removal (BCR) | UNCHANGED

Involves the pyrolysis of organic material to produce biochar, which stores carbon in a stable form when added to soil. This method can also improve soil health.

Biomass Geological Sequestration (BGS) | *CHANGED*

Previously, "Bio-oil Sequestration," this name has been updated to include other methods that store biomass geologically. It involves converting biomass into forms such as bio-oil or bioslurry and storing it in geological formations for long-term carbon storage.

Biomass Direct Storage | UNCHANGED

Directly stores terrestrial biomass in stable environments, such as controlled terrestrial storage sites or sinking to the deep sea, where decomposition is minimized, and carbon is sequestered over the long term.

[Image by Third Way]

Direct Air Carbon Capture and Sequestration (DACCS)

Direct Air Carbon Capture and Sequestration (DACCS) | *CHANGED*

The capture of CO₂ directly from the atmosphere using chemical processes combined with its permanent underground storage. We have updated the term from Storage to recognize the likelihood of the method using geologic sequestration.

[Image by Third Way]

Marine CDR (mCDR)

Alkalinity Enhancement | *CHANGED*

This has been updated to combine Ocean, River, and the emergent Coastal and Wastewater Alkalinity Enhancement methods under one category. This streamlined approach focuses on adding alkaline materials to aquatic systems to neutralize acidity and store carbon as bicarbonates or carbonates.

Direct Ocean Removal | UNCHANGED

Captures CO₂ directly from ocean water, reducing atmospheric concentrations as the ocean reabsorbs CO₂ to maintain equilibrium.

Marine Biomass Carbon Capture and Sequestration (MBCCS) | *CHANGED*

This new method combines Marine Biomass Sinking, which involves cultivating marine biomass, such as seaweed, and sinking it into deep ocean layers, and Microalgal Capture and Storage, which harnesses the carbon-capturing capacity of microalgae that can be processed into products or stored in stable environments. It can also include hybrid approaches where the biomass that captures the carbon is marine, rather than terrestrial, and where the sequestration occurs in a marine environment.

[Image by Third Way]

Enhanced Weathering (EW)

Enhanced Weathering (EW) | UNCHANGED

Accelerates the natural rock weathering process to remove CO₂ from the atmosphere. Crushed silicate rocks are spread across landscapes or oceans, where they react with CO₂ and lock it into mineral form. 

Mineralization

Mineralization | *CHANGED*

A broad category involving the conversion of CO₂ into stable mineral forms. This method now combines:

Ex-situ Mineralization

A carbon storage method in which captured CO₂ is reacted with alkaline minerals outside their natural setting - typically involving mined and ground rocks or industrial by-products - within engineered systems such as reactors or treatment facilities. The ex-situ element will be retained in our database as a method of storage.

In-situ Mineralization

A carbon storage method that involves injecting CO₂ into underground rock formations, where it reacts with naturally occurring minerals to form stable carbonates. While the process itself is storage-focused, the overall classification depends on the source of the CO₂; for example, CO₂ captured from biomass combustion qualifies the process as BECCS. The in-situ element will be retained in our database as a method of storage.

Microbial Mineralization

Leverages microbes to accelerate the natural process of converting CO₂ into stable mineral forms, such as carbonates. These microbes often enhance weathering reactions by producing acids or enzymes that facilitate the breakdown of silicate or carbonate rocks, enabling long-term geological storage of carbon. The microbial nature of the method will be retained as an attribute.

Surficial Mineralization

Applies alkaline minerals to surface environments where they passively react with atmospheric CO₂ to form carbonate minerals with the aim of enhancing the mineralization capacity of alkaline feedstock. The surficial nature of the method will be retained as an attribute.

What’s Next?

Our updated methods will be implemented across our platform as of end of day Jun 20, 2025 for transaction tracking, leaderboards, and market updates. These improvements reflect our commitment to transparency and innovation in the CDR ecosystem. If you’d like to share feedback or contribute, feel free to contact us at team@cdr.fyi.

Let’s work together to accelerate durable carbon removal and build a sustainable future!

Acknowledgments

Our deepest thanks to the many industry experts and contributors who helped shape these updates. A kind thank-you to the team at Third Way for providing the visual rendering of CDR projects used in this blog post.