The ocean absorbs about a quarter of all carbon dioxide (CO₂) released by human activity, helping to slow climate change—but at a cost.
This constant uptake of CO₂ increases ocean acidity, threatening marine life and delicate ecosystems.
Now, scientists have found a way to turn that problem into an opportunity: using the ocean’s dissolved carbon to create biodegradable plastics instead of relying on fossil fuels.
In a study published in Nature Catalysis, researchers led by Chuan Xia have developed a new system that can efficiently capture CO₂ directly from seawater and convert it into the building blocks of environmentally friendly plastic.
Their invention could one day make it possible to produce sustainable materials from ocean carbon while helping to reduce pollution and mitigate climate impacts.
“Our system provides a potentially sustainable way to turn carbon dioxide into valuable products,” said Xia. “It operates efficiently and continuously, using relatively little energy, and could be adapted to make a range of industrial chemicals.”
The research team designed a two-part process. The first part captures CO₂ from seawater with more than 70% efficiency while consuming just 3 kilowatt-hours of energy per kilogram of CO₂—about the same amount of electricity a standard household fan might use over a few days.
The process ran continuously for 536 hours, showing that it can be stable over long periods.
The cost of capturing CO₂ this way was estimated at US$229.9 per ton, making it competitive with other existing carbon capture technologies.
Once the CO₂ was separated from seawater, it was converted into formic acid, a simple compound, using an electrocatalyst—a material that speeds up chemical reactions with electricity. In the second step, the researchers fed this formic acid to engineered bacteria known as Vibrio natriegens. These bacteria then transformed it into succinic acid, a key ingredient for making poly(butylene succinate), a type of biodegradable plastic often used in packaging and agricultural films.
In larger-scale experiments, the team produced up to 1.37 grams of succinic acid per liter, showing that the process could be scaled up for industrial applications. The resulting plastic is not only biodegradable but also made from a renewable carbon source—offering a sustainable alternative to conventional plastics made from petroleum.
Beyond plastics, the researchers say their system could be adapted to create a variety of other useful products, such as fuels, pharmaceuticals, and food additives, by modifying the catalyst materials and the engineered microbes.
While the system is still in the research stage, it represents a major step toward closing the carbon loop—turning CO₂, one of the planet’s biggest environmental challenges, into valuable resources.
If successfully scaled up, this technology could help transform ocean carbon into a powerful tool for a cleaner, more sustainable future.
