By Max DuBuisson, VP, Head of Impact & Integrity, Indigo

Soil carbon has long been recognised as a promising tool for both climate change mitigation and adaptation by governments, scientists, and international organisations. Recently, the approach gained approval under the Core Carbon Principles of the Integrity Council for the Voluntary Carbon Market (ICVCM), an independent mark of integrity that positions soil-based carbon removals for rapid growth.

At the start of 2026, Microsoft entered into a a 12-year, 2.85 million soil carbon credit purchase agreement with Indigo, one of the largest soil carbon removal transactions to date. Last month, the Climate Action Reserve (Reserve) approved the fifth verification and credit issuance for Indigo’s project, CAR1459, bringing Indigo’s total verified impact to over two million tonnes of CO2-equivalent.

This momentum signals that not only is high-integrity soil carbon removal a credible, long-term solution amongst buyers, but that it has also become a large-scale lever that companies are now pulling with greater conviction to support their climate commitments. These are the visible results of a long period of disciplined groundwork from registries, NGOs, project developers, academics, farmers, and buyers.

From our perspective at Indigo, four key themes helped move agricultural soil carbon from a nascent category to the high-integrity climate solution that it is today. For those looking to understand what high-integrity soil carbon looks like in practice, or to explore how to engage with Indigo in building what comes next, we are sharing the lessons that got us here.

1. Make it possible:  Engage with existing market channels

The foundation for bringing high-integrity soil carbon removals to market at scale was engagement with the independent crediting programs that determine how carbon credits are issued. At Indigo, we believe that farmers will only see durable financial value if credits earn strong prices and are attractive to the largest number of buyers. To us, that meant working through widely-recognised bodies and adhering to industry best practices for credit integrity.

Because no existing methodology supported the scope, scale, and scientific rigour we required, we – along with our technical partners – worked with two of the leading crediting programs, the Reserve and Verra, to develop and secure approval for innovative new protocols for agricultural soil carbon accounting: CAR Soil Enrichment Protocol (SEP) and VCS VM0042, along with the associated VMD0053 modelling guidance module. Our US project has been developed under the CAR SEP v1.1.

Beyond methodology development, Indigo joined colleagues in agriculture and academia in more than 60 working groups and workstreams to ensure that soil carbon is meaningfully represented in the evolving market and policy landscape.

We invite you to read more on Indigo’s Carbon Resources webpage and the respective pages for CAR SEP and VM0042. Both methodologies are currently undergoing revisions, with opportunity for stakeholder feedback.

2. Make it credible: Scientific collaboration and transparency

Building market confidence requires transparency and collaboration with the scientific community. At Indigo, we pressure-test our approach for quantifying soil organic carbon through peer-reviewed publications, including Geoderma and the Journal of Environmental Management. External model experts independently review our model calibration and validation reports. The Reserve publishes these reports, along with the experts’ reviews and conclusions.

Critically, scientific research is strengthened by collaboration with farmers and partners, who can surface challenges and opportunities that models may miss. Over the years, we have conducted our own in-field research trials, collaborated with partners like NC State University and the Intertribal Land Tenure Foundation, and collected hundreds of thousands of individual management datapoints and soil samples on working lands. We’ve also collaborated with scientists at Woodwell Climate Research Center and the Soil Health Institute to advance the science on soil carbon measurements.

We continually engage the scientific community through direct conversations, participation in working groups, conferences and events (e.g. American Geophysical Union: 1, 2, and 3).

Advancing science is a team sport. The long-term, on-farm trials that Indigo started five years ago are now being managed by a non-profit, the Soil Health Institute, with the goal to make the data and learnings available to the broader scientific community. Maintaining these sites for long-term monitoring supports further methodological improvements. To ensure that this important work continues and grows, we need the broader soil carbon community to rally behind this effort: reach out to Daniel Liptzin at [email protected].

3. Make it successful: Communicating so the VCM and its participants win

For soil carbon removal to work at scale, farmers and buyers must speak the same language and reap equitable benefits. Indigo communicates with farmers directly through our software application, newsletters, payment reports, digital tools, and through our partners, who have local, in-person relationships. As often as possible, we combine these channels through in-person field days.

For independent verification, we have developed extensive documentation and data packages and we also provide the verifiers access to farm data directly through our software platform.

For buyers and other stakeholders, we provide copious documentation through our public website, a data room, and interactive mapping tools to make the project more accessible.  Indigo’s project, CAR1459, has also received BBB ratings from both BeZero and Sylvera, two of the leading ratings services. The BBB rating indicates that the project meets a high standard of integrity and the ratings details can jumpstart the due diligence process, giving buyers an indication of areas of strength or potential risk.

4. Make it collaborative: Nurture cross‑stakeholder engagement

Beyond direct, bilateral engagement, we’ve collaborated to establish and convene forums where stakeholders with differing priorities can engage constructively. For example, Indigo launched our annual Regenerative Agriculture Science & Policy Forum in 2022 to foster dialog with these diverse groups.

As soil carbon project development scaled around the world, it became clear that the sector needed a louder, clearer, more coordinated voice. This shared recognition among global practitioners ultimately resulted in the establishment of the International Soil Carbon Industry Alliance (ISCIA), of which Indigo is a founding member. ISCIA members collaborate to share information, contribute to policy development, and advance the reputation of soil carbon in markets around the world.

Details regarding ISCIA membership, publications, and events can be found at ISCIA.org.

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Taken together, these four themes have enabled agricultural soil carbon to mature and scale into a trusted climate solution. We invite researchers, farmers, policymakers, buyers, and all stakeholders in the carbon ecosystem to join the conversation to continue advancing soil carbon as a scalable, credible climate solution.

Max DuBuisson is VP, Head of Impact & Integrity at Indigo, which has founded in 2013 with the aim of harnessing nature to help farmers sustainably feed the planet.

Any opinions expressed in this commentary reflect the views of the authors and not of Carbon Pulse.

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