Running Tide

The company's primary business was focused on carbon dioxide removal (CDR) through various ocean-based pathways. Its business model involved selling carbon removal credits to corporate clients seeking to offset their emissions and meet environmental, social, and governance (ESG) goals. High-profile clients included Microsoft, Shopify, Stripe, and the Chan Zuckerberg Initiative. Running Tide's approach was to move carbon from the fast-moving atmospheric cycle to the slow cycle in the deep ocean for long-term storage.

The core of Running Tide's service involved deploying specially designed "Carbon Buoys." One method involved sinking terrestrial biomass, such as waste wood from forestry operations, coated with limestone into the deep ocean. This process aimed to sequester the carbon embodied in the wood for thousands of years and simultaneously use the dissolved limestone to counteract ocean acidification. Another pathway the company explored was growing macroalgae, like kelp, on buoys in the open ocean. The kelp would absorb atmospheric carbon through photosynthesis as it grew, and upon sinking, would transport that carbon to the deep sea floor. The company operated research and deployment centers in Portland, Maine, and Iceland.

Despite delivering carbon removal credits to major clients like Microsoft and Shopify, Running Tide faced significant challenges. The company announced it was shutting down its global operations in June 2024, citing an inability to secure the necessary financing to continue its work at the required scale. The high costs associated with open-ocean deployments and a lack of sufficient demand in the voluntary carbon market were cited as primary reasons for its closure. At its peak, the company employed around 120 people. Keywords: ocean carbon removal, carbon credits, biomass sinking, ocean alkalinity enhancement, kelp sequestration, climate technology, marine ecosystems, Marty Odlin, Shopify, Microsoft