Japan is stepping up its blue carbon activity on two fronts. The country's Ministry of Environment (MoE) has announced a JPY300 million ($1.9 million) subsidy programme for seaweed-based carbon removal projects, and a Japanese developer has signed a five-year agreement with an Indonesian partner to advance mangrove restoration.
Scientists studying coastal ecosystems and biodiversity for blue carbon projects in a tropical mangrove forest in Indonesia. AI generated picture.
Blue carbon refers to the carbon stored in coastal and marine ecosystems, principally mangroves, tidal marshes, and seagrasses. These habitats are valued for their capacity to absorb and store CO₂, as well as for co-benefits including coastal protection and biodiversity support.
The MoE subsidy will fund up to three projects with JPY100 million each, covering a period through to 31 March 2027. Selected developers will identify and cultivate seaweed seedlings, then transfer and sink them to sufficient sea depth. Projects are required to establish measurement and verification systems for carbon storage and share findings with the MoE, retaining the rights to any carbon credits generated. Applications are open to private companies, universities, and research organisations until 30 April.
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On the project development side, Green Carbon and Pesisir Lestari have signed a Memorandum of Understanding (MoU) targeting over 1,000 hectares of potential mangrove restoration sites in Indonesia, identified through remote and field surveys. The partnership will focus on building tools to accurately estimate carbon accumulation in both biomass and sediments, as well as calculating annual sequestration potential over a 35-year period. Pesisir Lestari claims to have helped conserve 2,100 mangrove and coastal ecosystems to date.
Both developments reflect the growing maturity of Japan's blue carbon market, which is underpinned by the voluntary J-Blue Credit scheme, administered by the Japan Blue Economy Association (JBE). Credits are issued for CO₂ removal by seaweed, seagrass, and mangroves. In December, trading house Itochu Corporation became the first Japanese company to obtain blue carbon credits from JBE, through a mangrove planting project in southern Japan. The Japanese government amended its domestic J-Credit scheme in 2024 to allow the creation of carbon dioxide removal credits (CDRs) from blue carbon projects, though a formal methodology is yet to be established.
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At Green Earth, we develop nature-based carbon projects that go beyond carbon storage: restoring ecosystems, supporting biodiversity, and delivering measurable environmental value across international markets. As carbon sequestration moves from emerging science to verified market reality, end-to-end project development grounded in ecological expertise and rigorous standards becomes the difference between ambition and impact. We combine data intelligence, on-the-ground experience, and accreditation by leading verification standards to engineer possibilities at scale to support businesses in achieving their green goals.
