Running Tide

Running Tide was a Portland, Maine-based ocean carbon removal company that developed scalable, nature-based methods to sequester carbon dioxide from the atmosphere via the ocean. The company initially focused on macro-algae cultivation and sinking, later pivoting to sinking wood biomass at scale. Running Tide removed approximately 25,000 tons of CO2 equivalent in its final operating year and delivered roughly 21,000 verified carbon credits to enterprise buyers including Microsoft and Shopify. The company maintained a science-first approach, publishing an open framework protocol for ocean carbon removal and partnering with Deloitte for ISO-certified credit verification. Running Tide raised over $50 million from investors and employed more than 100 people at its peak, with offices in Portland, Maine and Iceland. The company ceased global operations in June 2024, citing insufficient demand in the voluntary carbon market.