Startups Using the Ocean for Carbon Capture

Oceans help cool the Earth and absorb about 30 percent of our annual carbon dioxide (CO2) emissions, according to the Commonwealth Scientific and Industrial Research Organisation. Enhancing the oceans’ capacity to absorb CO2 from the atmosphere presents a highly promising avenue for mitigating or reversing the pace of global warming.

Vesta is pioneering a project involving sand mixed with the yellow-green mineral olivine. As this combination dissolves in seawater, it reduces ocean acidity and facilitates carbon removal. In July 2024, the company completed its first deployment of 8,200 metric tons of olivine off the coast of North Carolina, achieving an estimated capture of 5,000 metric tons of CO2.

Equatic is operating a small pilot facility in Southern California that uses electrochemistry to augment the ocean’s natural carbon absorption process by separating the elements of water and storing the dissolved carbon as a solid. A key aspect of Equatic’s approach is the ability to accurately measure the CO2 removed before discharging the seawater back into the ocean. Additionally, their process produces hydrogen, which is subsequently sold as a green fuel and can offset up to 40 percent of the energy consumed during the process.

Despite these advances, the carbon removal industry faces significant challenges in achieving financial viability. Notably, Running Tide shut down after failing to sell sufficient carbon credits to sustain its operations. The company had strategically buried plant material in deep water near Iceland, preventing its decomposition and the release of stored carbon.