RUNNING TIDE

Marty Odlin grew up fishing with his family in Maine. His father was a lobsterman.

He studied engineering at Yale, then spent years working as a naval engineer on submarine systems. He understands the ocean — not as a concept, but as a physical system he has worked in and around his entire life.

In 2020, he founded Running Tide on the thesis that the ocean is the most underused tool in the carbon removal toolkit. The ocean already absorbs roughly 25% of annual human CO2 emissions through natural processes.

Odlin's insight: you can accelerate that process by growing and sinking carbon-absorbing biomass — kelp, wood chips, biochar — in a way that deposits the carbon on the deep ocean floor, where pressure and temperature keep it locked away for thousands of years. He built the company in Portland, Maine, close to the fishing infrastructure and ocean expertise his model requires.

Stripe Climate was one of the earliest buyers of Running Tide's carbon credits, giving the company both the revenue and the credibility to raise institutional funding.

Running Tide sells carbon removal credits to large corporations trying to meet net-zero commitments. Buyers — Stripe, Alphabet, Microsoft, and others — pay a price per tonne of CO2 permanently removed from the atmosphere.

Running Tide deploys buoys loaded with kelp and wood pulp into the ocean, the biomass grows and absorbs CO2, then sinks to the deep ocean floor. The carbon stays there for geological time scales.

Revenue is carbon credit sales. The cost structure involves growing or sourcing the biomass, deploying buoys at scale, and monitoring and verification to prove the carbon actually stayed down.

Long-term, the model works if the cost per tonne of removal falls below the price corporations are willing to pay — which today ranges from $100 to over $1,000 per tonne for high-quality permanent removal.

Running Tide's core product is ocean-based carbon removal credits — permanent, verified tonnes of CO2 removed from the atmosphere and stored in the deep ocean. The delivery mechanism is proprietary buoys loaded with kelp and sustainably sourced wood biomass, deployed into ocean regions where deep-water sinking occurs naturally.

The company also produces biochar — charcoal produced from biomass that can be sunk or used in soil applications. Their monitoring and verification system uses sensors, autonomous vehicles, and satellite data to track deployment and estimate carbon sequestration.

As a secondary product, they sell data and methodology transparency reports to buyers who need documentation for their own corporate sustainability reporting.

The strategy is quality and credibility first, volume second. Running Tide deliberately targeted the most demanding buyers in the voluntary carbon market — Stripe Climate, Alphabet, and Microsoft — because those buyers require rigorous monitoring, reporting, and verification.

Delivering credibly to them builds the scientific and commercial track record needed to access larger contracts and a wider buyer base. The company also benefits from the broader ocean CDR ecosystem: academic partnerships with oceanographic institutions, data sharing with climate researchers, and active participation in developing MRV (measurement, reporting, and verification) standards for ocean carbon removal.

Being the company that helped write the scientific playbook for ocean CDR is a durable competitive advantage.

Scientific uncertainty. Ocean carbon removal is not like solar panels or wind turbines — it does not have 40 years of deployment data.

Whether kelp sinking actually keeps carbon in the deep ocean permanently, whether it changes local ocean chemistry in problematic ways, and how to measure removal accurately are all questions that the scientific community is still actively researching. In 2023, some oceanographers publicly raised concerns about the validation methodologies used by ocean CDR companies.

Running Tide has responded by investing heavily in monitoring and being transparent about uncertainty. But if the science ultimately does not support ocean biomass sinking as a reliable carbon removal pathway, the company's entire model is undermined.

That is a specific and meaningful risk that most other clean energy companies do not carry.

Breakthrough Energy Ventures led the Series A in 2023, providing the most credible possible institutional endorsement for the technology. Union Square Ventures was an early backer — Fred Wilson's firm has a long history of backing founders with unconventional backgrounds who are building for structural change.

DCVC (Data Collective) invested because of the data and monitoring infrastructure embedded in the model. Stripe's early credit purchases were not equity — but they functioned as the seed commercial relationship that proved the business could find buyers before it had a full scientific record.

Alphabet and Microsoft's credit purchases followed.