In a remarkable transformation from a struggling family tea estate to a leading climate-tech venture, Alt Carbon has secured a $12 million seed funding round to scale its carbon dioxide removal efforts in India. The investment, led by Lachy Groom, co-founder of the robotics AI company Physical Intelligence, marks a significant step forward for the startup founded by siblings Shrey and Sparsh Agarwal. Their journey began in May 2020 with a 16-hour drive from Kolkata to Darjeeling, a city renowned for its tea production. Instead of closing down their family's tea estate, Salem Hill, due to looming bankruptcy, the Agarwals discovered an innovative solution to revitalize the region's agricultural landscape: enhanced rock weathering. Enhanced rock weathering involves spreading waste basalt rock dust from local mines and quarries onto farmlands, where it reacts with rainwater to absorb carbon dioxide and enrich the soil. This process not only helps sequester carbon but also improves soil fertility and crop yields. In 2023, Alt Carbon initiated a pilot project on approximately 500 acres of their family's tea estate, later expanding to cover rice and bamboo farms across North Bengal. Their ambitious goal is to scale this initiative to 500,000 hectares of land, aiming to remove 5 million tons of carbon from the region by 2030. Alt Carbon's proprietary blend, Hari Maati (meaning "green soil" in Hindi), combines basalt with organic materials to make the product more appealing to farmers. By leveraging existing mining and crushing operations, the startup mitigates additional emissions associated with rock processing and transportation. They estimate their carbon credits at $270 per metric ton, a fraction of the cost of direct air capture methods, which are believed to be around $800 a ton. The founders expect to further reduce these costs within the next 36 to 48 months. To ensure accuracy and transparency, Alt Carbon employs a multi-layered measurement system. The first layer tracks the weathering process, followed by analyses of soil water and groundwater sampling. The third layer utilizes proprietary reactive transport models and machine learning to monitor the movement of bicarbonate ions from the soil to water bodies and finally to the ocean, where they settle as calcium carbonate, locking carbon for over 10,000 years. These models comply with standards set by carbon removal registries like Isometric and Puro.earth, and have received approvals from intergovernmental organizations such as SBTi, ICVCM, and CORSIA. The startup's rapid progress has been bolstered by significant financial commitments and partnerships. In 2022, Alt Carbon secured a $500,000 pre-purchase deal from Frontier and joined a $1 billion advanced market commitment led by Stripe, Alphabet, Meta, Shopify, and McKinsey. More recently, they signed a strategic partnership with NextGen, a buyer coalition started by South Pole and Mitsubishi Corporation, comprising companies like BCG Group, Swiss RE, LGT, and UBS. Additionally, in August 2023, Alt Carbon inked an offtake agreement with Japan’s MOL Group to purchase 10,000 tons of carbon removal credits. With its headquarters in Darjeeling and a satellite lab in Bengaluru, Alt Carbon currently employs 8 to 10 PhDs and has a total headcount of 25 staff members. The seed round will enable the company to scale its lab facilities, enhance data collection through remote sensing and ground sensors, and deepen its impact on local agriculture. The first batch of carbon credits is expected to be delivered within a month, as verified by Isometric. Industry experts have praised Alt Carbon's approach for its dual benefits of carbon sequestration and soil improvement. They believe the startup’s model could serve as a blueprint for other regions facing similar challenges. Alt Carbon’s innovative use of waste materials and low-cost methods sets it apart in the rapidly growing field of climate tech, offering a sustainable solution that aligns with both environmental and economic goals. The company’s strong network of partnerships and approvals from key organizations underscores its potential to make a significant impact on global carbon removal efforts. Alt Carbon, with its roots in a tea estate and a vision for a greener future, represents a powerful example of how local solutions can address global problems. As the company continues to scale, it may inspire similar initiatives in other parts of the world, contributing to the fight against climate change while supporting rural communities.