Alt Carbon Enhanced Rock Weathering

Alt Carbon is a deep-tech science and data company with a Bengaluru, India address and a San Francisco and Bangalore press footprint. It builds carbon dioxide removal (CDR) infrastructure in South Asia, with a stated mission of removing 5 million tons of CO2 by 2030.

Its main method is enhanced rock weathering: waste basalt rock dust, combined with organic inputs in a product called Hari Mati, is spread on farmland such as tea estates in Darjeeling, where it improves soil and locks CO2 away as bicarbonate and later carbonate. Removals are measured in its own lab, verified on the Isometric registry and sold as credits to corporate buyers such as Microsoft and Mitsui O.S.K. Lines.

• Enhanced rock weathering: basalt rock dust spread on agricultural land to capture CO2 as bicarbonate.
• Hari Mati product: proprietary blend of organic inputs and silicate-rich amendments for soil.
• Darjeeling Climate Action Lab: in-house lab for measurement and modeling, launched in October 2024.
• Registry verification: credits issued on the Isometric registry.
• Offtake contracts: multi-year credit deliveries to corporate buyers.

Vietnamese exporters and multinationals with net-zero targets can buy Asian ERW credits through offtake contracts. Agricultural cooperatives and plantation owners in Vietnam could study rock-dust programs modeled on tea estates. Carbon project developers can benchmark MRV practice against the Isometric-verified Darjeeling approach.

Buyers obtain durable removal credits issued on the Isometric registry, with storage stated as over 10,000 years. Alt Carbon reports 9,566 verified credits from the Darjeeling Revival Project as of May 2026. Multi-year offtake deals (Microsoft, MOL Group, Frontier) give buyers forward supply. Farmland gets rock dust that also supports crop yields.

Demand for durable carbon removal is rising as corporate buyers seek credits beyond avoidance offsets. Tropical and monsoon farmland is seen as well suited to rock weathering, and Asian buyers such as Mitsubishi and MOL are contracting South Asian supply. Vietnam and Southeast Asia have large rice and plantation areas that could host similar programs.

Raised a 12 million USD seed round led by Lachy Groom (announced May 2025). Agreements with Mitsubishi Corporation (March 2025), a 500K USD prepurchase from Frontier (September 2024) and credit deliveries to Mitsui O.S.K. Lines. Footer address: Alt Carbon Tech Pvt. Ltd., IISc iHub, Bengaluru.