When Mike Kelland first explained his company's technology, he'd sometimes reach for the most unlikely analogy: Think of it as Tums for the ocean. Industrial-strength Tums, sure—but the concept holds. Add the right alkaline minerals to seawater, and you can turn Earth's oceans into massive, permanent carbon sinks.
Three years after that pitch helped secure CAD $7.8 million in early funding, the Halifax-based startup Planetary Technologies has emerged as the unlikely front-runner in ocean alkalinity enhancement, a carbon removal method that until recently lived mostly in academic papers and climate hypotheticals.
The numbers tell part of the story. In March 2022, Planetary announced its initial raise—CAD $4.2 million in combined pre-seed and seed equity, plus CAD $3.6 million in grants. Innovacorp (now doing business as Invest Nova Scotia) led the round alongside Apollo Projects, the early-stage fund managed by Sam Altman's brothers. Regional outlets noted the Apollo connection at the time, a signal that the Altman orbit was placing bets on ocean-based climate solutions before they'd become fashionable in Silicon Valley.
Founded in October 2019, Planetary pairs Kelland, a software entrepreneur with no background in oceanography, and Dr. Greg Rau, a biogeochemist who'd spent decades studying how to manipulate ocean chemistry for climate benefit. Their method—Ocean Alkalinity Enhancement, or OAE in industry shorthand—involves dosing seawater with magnesium hydroxide through existing coastal outfalls. The alkalinity neutralizes carbonic acid, allowing the ocean to pull more CO₂ from the atmosphere. Once absorbed, carbon gets stored as bicarbonate for somewhere between 10,000 and 100,000 years. Most land-based sequestration methods can't promise that kind of permanence.
Early Believers
What separated Planetary from the dozens of carbon removal startups chasing venture dollars was its ability to land customers before it had fully proven the technology at scale. Shopify became the first buyer in January 2021, pre-purchasing future carbon removals through its Sustainability Fund—a bet on pilot operations that hadn't yet produced verifiable results. Stripe followed through Frontier, its ambitious climate commitment vehicle.
The company offered 3,000 carbon credits for retirement between 2025 and 2027. Optimistic, perhaps more than the founders initially let on. But by November 2024, Planetary delivered 138 tonnes of net OAE credits to those first two customers. Then in June 2025 came the milestone: 625.6 verified tonnes issued to Stripe, Shopify, and British Airways. The Isometric registry confirmed them as the world's first verified ocean alkalinity enhancement credits—a designation that matters more than it sounds, given how many carbon removal claims evaporate under scrutiny.
Building Infrastructure
Between that seed round and today, Planetary has accumulated the kind of validation that turns curiosity into credibility. An XPRIZE Carbon Removal milestone award in April 2022 brought $1 million. Active dosing began at Halifax Harbour in September 2023—not a lab simulation, but real ocean water, real alkalinity, real monitoring.
September 2024 brought an $11.35 million Series A. Evok Innovations led, with BDC Capital, Amplify Capital, and DNX Ventures participating. The round valued practical progress over pure promise: pilot facilities in Quebec and Nova Scotia, integration with established ocean research networks, a growing dataset on how OAE performs outside controlled conditions.
Then came August 2025 and the deal that repositioned Planetary from promising experiment to commercially viable operation. Frontier committed $31.3 million to purchase 115,000 tonnes of CO₂ removal through 2030. The buyer consortium reads like a who's who of corporate climate action—Stripe and Shopify again, plus Google, McKinsey Sustainability, Autodesk, H&M Group, and Workday. At the time of announcement, it marked the largest ocean alkalinity enhancement contract on record.
The arrangement matters less for its size than for what it signals. These aren't speculative purchases or PR exercises. Companies are paying for verified tonnes at commercial rates, accepting the risks inherent in scaling unproven technology. Planetary still needs to deliver on that 115,000-tonne promise, a tall order for a company that had verified fewer than 800 tonnes total just months earlier.
Kelland has said the company's 2030 target sits at one million tonnes annually—ambitious but not entirely unreasonable given the infrastructure already operational. Whether oceans prove a scalable carbon sink or remain a niche solution depends largely on whether Planetary and its handful of competitors can make the economics work without perpetual subsidies.
For now, the antacid metaphor still works. Just significantly more complex than anything you'd buy at a pharmacy.
