Alt Carbon Raises 12M to Scale Carbon Removal in India

Alt Carbon, a pioneering climate-tech startup based in India, has successfully raised $12 million in a seed funding round to expand its innovative carbon dioxide removal (CDR) technology. The company’s mission is to combat climate change by locking away carbon for thousands of years through enhanced rock weathering applied to farmlands.

The journey of Alt Carbon began in 2020 when siblings Shrey and Sparsh Agarwal returned to their family’s struggling tea estate in Darjeeling, India. Facing bankruptcy, they sought ways to revive the estate and discovered the potential of carbon markets and enhanced rock weathering as a sustainable solution. This led to the official launch of Alt Carbon in late 2023.

Enhanced rock weathering involves spreading waste basalt rock dust—sourced from mining and quarrying operations—on farmland. When rainwater interacts with the basalt dust, it reacts with atmospheric carbon dioxide to form stable bicarbonate ions. These ions are stored in the soil and eventually transported to oceans, where carbon is locked away as calcium carbonate for over 10,000 years.

This process not only removes carbon but also enriches soil fertility and enhances crop yields, providing dual benefits to farmers. Alt Carbon has developed a proprietary soil amendment called Hari Maati, combining basalt dust with organic ingredients to encourage adoption among local farmers.

Currently, Alt Carbon operates pilot projects on 500 acres of tea, rice, and bamboo farms in North Bengal, with plans to scale to 500,000 hectares. Their ambitious goal is to remove 5 million tons of carbon dioxide by 2030, positioning the region as a leader in climate action.

To accurately measure carbon removal, Alt Carbon employs a three-layered approach: tracking weathering progress, analyzing soil and water samples, and utilizing proprietary reactive transport models. Machine learning further refines carbon removal estimates, ensuring compliance with global carbon registries and standards such as Isometric, Puro.earth, SBTi, ICVCM, and CORSIA.

The startup’s operational model emphasizes sustainability by using waste basalt dust from existing mining activities and leveraging existing freight systems to minimize emissions. This approach significantly reduces costs compared to other carbon removal technologies like direct air capture.

Alt Carbon’s recent seed round, led by Lachy Groom, co-founder of robotics AI company Physical Intelligence, will fund scaling efforts including expanding lab capabilities, deploying ground sensors, and enhancing remote sensing for better data collection and analysis.

The startup has also secured significant pre-purchase commitments and strategic partnerships with global corporations and coalitions, including Frontier, Stripe, Alphabet, Meta, Shopify, McKinsey, NextGen, and MOL Group, reflecting strong market confidence in its carbon removal potential.

Alt Carbon exemplifies how innovative climate technologies can transform traditional industries and regions vulnerable to climate change into leaders in sustainability. By integrating AI-driven modeling, advanced measurement techniques, and sustainable resource use, the startup is setting a new standard for scalable, cost-effective carbon removal.