A New Industry-First Protocol for Carbon Removal via Rivers: Now Open for Public Consultation

Isometric’s newly released RAE Protocol is the first of its kind, establishing a rigorous, science-backed framework for verifying carbon removal through river-based alkalinity enhancement. This protocol is now open for public consultation, inviting feedback from buyers, suppliers, and scientists over the next 30 days.

How RAE Works

RAE involves carefully adding finely crushed alkaline rocks—such as limestone—into river water. These materials react with carbon dioxide in the river, converting it into stable carbonate and bicarbonate ions. This prevents carbon dioxide from being released into the atmosphere and allows it to be transported to the ocean, where it remains stored for tens of thousands of years. While the concept of river liming has been used for decades to manage acidification and protect aquatic species like salmon and trout, its potential as a climate solution is only now being fully realized.

Key Elements of the Protocol

The RAE Protocol introduces a scientifically rigorous approach to measurement, reporting, and verification (MRV), ensuring that each carbon credit issued represents a tonne of carbon dioxide durably removed from the atmosphere. Three critical elements define this framework:

• Flexible Quantification Framework: No two rivers are alike. The protocol employs a flexible quantification framework that adjusts to site-specific conditions, capturing the full dynamics of RAE from the point of alkalinity addition to ocean storage. This ensures robust and accurate tracking of carbon removal.
• Direct Measurement of Alkaline Feedstock Weathering: By measuring river chemistry at multiple points after alkalinity is introduced, the protocol provides high confidence in the quantification of carbon removal.
• Dynamic Baseline Accounting: The protocol accounts for the natural variability of rivers by establishing a dynamic baseline using statistical and process models. These models consider factors like water flow, temperature, and pH levels, ensuring accurate measurement of changes resulting from RAE.

CarbonRun’s Role in the Protocol’s Development

As a leader in RAE deployment, CarbonRun played a key role in shaping this protocol.

Shannon Sterling, CarbonRun’s Founder and COO/CSO, shared her perspective on the protocol’s release:

“Rivers are the critical link in the global carbon cycle between terrestrial sources and ocean sinks. For over four years, the CarbonRun team has worked with Dalhousie University and the Nova Scotia Salmon Association on the question of how alkalinity additions for river restoration can also remove carbon dioxide. It is so exciting to see this work come to fruition.

“The Isometric team has developed a River Alkalinity Enhancement protocol that leverages the unique strengths of rivers, including the ability to observe CDR in real time. We’ve tested the protocol in the field and are excited about its ability to support MRV that is efficient, affordable, practical and builds trust. River Alkalinity Enhancement has the potential to help mitigate the worst effects of climate change while restoring our rivers and estuaries.”

Public Consultation Now Open

The RAE Protocol was developed in line with the Isometric Standard, through collaboration between Isometric’s in-house Science Team and reviewers from Isometric’s independent Science Network of over 300 scientific experts.

Now, Isometric is inviting feedback from key stakeholders, including carbon credit buyers, RAE suppliers, and the broader scientific community. The public consultation period will last for 30 days, providing an opportunity to refine and strengthen the protocol before its finalization, which ends on April 26, 2025.

As a company committed to advancing science-backed carbon removal solutions, CarbonRun encourages all interested parties to review the protocol and contribute their insights.