Today Isometric published the world’s most comprehensive Protocol for permanent carbon removal via Direct Air Capture (DAC). The Protocol details how DAC technologies—which capture carbon dioxide from ambient air—can be monitored, reported on, and verified so that buyers can purchase DAC carbon credits with confidence.

Isometric protocols set the bar for what project developers need to measure to demonstrate that carbon dioxide has been removed from the atmosphere and safely stored. All Isometric protocols are developed in line with the Isometric Standard, which is the world’s most stringent set of rules for carbon removal. 

This DAC Protocol was created in collaboration between Isometric’s in-house Science Team, reviewers from Isometric’s independent network of over 200 scientists, and Isometric’s cross-industry working group. This working group brought together more than a dozen suppliers, including Montreal-based carbon removal project developer, Deep Sky.

DAC technologies pass ambient air into a structure known as a contactor. Inside this contactor, air is exposed to materials which react with carbon dioxide—such as solid sorbents or liquid solvents. In the contactor, the atmospheric carbon dioxide binds to these materials, while the other components of the air (such as nitrogen and oxygen) pass through back into the air. The captured carbon dioxide is recovered and compressed using heat, pressure, or electro-chemical displacement.

Carbon dioxide is present at relatively diluted concentrations (parts per million) in the atmosphere. This means substantial energy is required to remove and concentrate it via DAC. Isometric’s Protocol ensures that energy use for DAC does not lead to secondary emissions through the diversion of renewable energy. The Protocol requires direct power purchase agreements (when feasible) and quantifying the procurement of grid energy. This is the most scientifically accurate way of calculating DAC removals, allowing us to issue credits that buyers can actually trust. 

As part of Isometric’s commitment to transparency, the Protocol is now undergoing a full public consultation before it is finalized and used for issuing credits on the Isometric Registry. 

This protocol follows Isometric’s Bio-oil geological storage protocol last week. Protocols for two other carbon removal methods will be published in the next few months: enhanced rock weathering and ocean alkalinity enhancement, to bring the total number of published Isometric protocols to four.

The publication of the DAC Protocol is another step towards creating trust and transparency in carbon markets. This is what is required to help carbon removal scale to the level that the planet needs and is what Isometric was founded to do.