Seachange leverages the power and scale of the world’s oceans to remove carbon. Its experimental electrochemical process sequesters CO₂ in seawater as carbonates, an inert material comparable to seashells, thereby enabling energy-efficient and permanent CO₂ removal.

Running Tide removes carbon by growing kelp in the open ocean. After maximum growth, the free-floating lines of kelp sink to the deep ocean where the embodied carbon is stored for the long term. Running Tide’s approach is simple and scalable, powered by photosynthesis, ocean currents and gravity.

Over geological timescales, CO₂ chemically binds to minerals and permanently turns to stone. Heirloom is building a direct air capture solution that enhances this process to absorb CO₂ from the ambient air in days rather than years, and then extracts the CO₂ to be stored permanently underground.

Mission Zero electrochemically removes CO₂ from the air and concentrates it for a variety of sequestration pathways. Its experimental room-temperature process can be powered with clean electricity and has the potential to achieve low costs and high volumes using modular, off-the-shelf equipment.

CarbonBuilt’s process readily converts dilute CO₂ into calcium carbonate, creating a “no compromise” low-carbon alternative to traditional concrete. As a profitable and scalable solution for permanent CO₂ storage, CarbonBuilt’s technology platform can serve as a critical component of future carbon removal systems using direct air capture.

Future Forest is conducting a field trial to accelerate mineral weathering by crushing basalt rocks into dust, spreading them onto the forest floor, and then measuring CO₂ uptake. This first-of-a-kind trial will help assess the potential for scale as well as the potential ecosystem impacts associated with enhanced weathering.

Climeworks uses renewable geothermal energy and waste heat to capture CO₂ directly from the air, concentrate it, and permanently sequester it underground in basaltic rock formations with Carbfix. While it’s early in scaling, it’s permanent, easy to measure, and the capacity of this approach is theoretically almost limitless.

CarbonCure injects CO₂ into fresh concrete, where it mineralises and is permanently stored while improving the concrete’s compressive strength. Today they source waste CO₂, but represent a promising platform technology for permanent CO₂ storage, a key component of future carbon removal systems.

Project Vesta captures CO₂ by using an abundant, naturally occurring mineral called olivine. Ocean waves grind down the olivine, increasing its surface area. As the olivine breaks down, it captures atmospheric CO₂ from within the ocean and stabilises it as limestone on the sea floor.

Charm Industrial has created a novel process for preparing and injecting bio-oil into geologic storage. Bio-oil is produced from biomass and maintains much of the carbon that was captured naturally by the plants. By injecting it into secure geologic storage, they’re making the carbon storage permanent.