Norway Turns Ocean Forests Of Seaweed Into Weapons Against Climate Change
Written by Matthew Russell
Off Trøndelag’s coast, long lines of kelp now do double duty. They grow fast. They also lock away carbon. A new pilot farm near Frøya aims to turn that promise into measurable removal of CO₂ from the air, according to DNV.
The site spans 20 hectares and carries up to 55,000 meters of kelp lines. First seedlings went in last November. The goal is proof of concept, then scale.
How the Pilot Works
The three-year Joint Industry Project, JIP Seaweed Carbon Solutions, brings SINTEF together with DNV, Equinor, Aker BP, Wintershall Dea, and Ocean Rainforest, with a total budget of NOK 50 million, Safety4Sea reports.
Researchers expect an initial harvest of about 150 tons of kelp after 8–10 months at sea. Early estimates suggest that biomass could represent roughly 15 tons of captured CO₂. This is a test bed for methods that can be replicated and expanded, DNV explains.
There’s a second step, as kelp becomes biochar. That process stabilizes carbon for the long term and can improve soils on land, SINTEF’s team told Safety4Sea. The project is designed to test both the removal and the storage.
A Long History, A New Mission
Seaweed isn’t new here. Norwegians have cultivated kelp since the 18th and 19th centuries for fertilizer and feed. Scientists advanced modern methods in the 1930s, laying the groundwork for today’s farms, according to SeaweedFarming.com. Cold, nutrient-rich waters support species like Laminaria and Saccharina. They grow quickly and draw down dissolved carbon and nitrogen.
The country’s aquaculture backbone also helps. Norway already runs one of the world’s most advanced seafood sectors. That expertise now extends to macroalgae.
Policy, Permits, and Ecosystems
Commercial cultivation began receiving specific permits in 2014, and activity has expanded across several coastal counties, according to a study in Aquaculture International. Researchers detailed the risks that accompany scale: genetic interaction with wild kelp, habitat impacts, disease, and space conflicts. Integrated Multi-Trophic Aquaculture, where seaweed grows alongside finfish, can recycle nutrients from farms and reduce eutrophication pressures.
Engineering for Open Water
Getting beyond sheltered bays is crucial. One path is the “Seaweed Carrier,” a sheet-like offshore system that lets kelp move with waves in deeper, more exposed water. It supports mechanical harvesting and industrial output without using land, Business Norway explains. The same approach can enhance water quality by absorbing CO₂ and “lost” nutrients.
The Frøya project is small in tonnage but big in intent. It links Norway’s long kelp lineage with new climate tech: fast-growing macroalgae, verified carbon accounting, and durable storage as biochar. If these methods prove reliable at sea and on shore, Norway will have more than a farm. It will have a blueprint for ocean-based carbon removal that others can copy.
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