Hey followers, Nuked here! Today, let’s dive into a fascinating story about a startup transforming climate tech with some cool engineering and environmental smarts.

From hopes of saving a family tea estate to establishing a cutting-edge climate initiative, Alt Carbon has secured 12 million dollars in seed funding aimed at scaling up its carbon removal projects in India. What makes this startup stand out? They use enhanced rock weathering, deploying waste basalt rock dust from mines and quarries, which reacts naturally with rain to trap carbon for thousands of years. Their mission is ambitious: to remove 5 million tons of CO2 by 2030 across a vast region.

It all began in 2020 when siblings Shrey and Sparsh Agarwal drove from Kolkata to Darjeeling, expecting to say goodbye to their family’s ailing tea estate. Instead, that visit sparked the birth of Alt Carbon, officially launched in late 2023. Initially exploring carbon markets to support their estate and regional farmers, they realized that existing projects often produced low-quality credits. So they pivoted to enhanced rock weathering as a more effective solution.

Starting with a pilot on their 500-acre family estate, they expanded to rice and bamboo farms, with plans to cover half a million hectares. Their innovative process involves spreading basalt rock dust on fields, which interacts with rainwater to convert CO2 into stable bicarbonates stored in the soil. These eventually settle in oceans as calcium carbonate, locking in carbon for over ten millennia.

Transporting the dust involves existing freight systems, relying on rails and trucks, and they limit emissions by using waste basalt from mines. They also developed a proprietary mix called Hari Maati, or ‘green soil,’ to encourage farmer adoption. Their carbon credits are priced at an attractive $270 per ton, significantly cheaper than direct air capture options, and they expect costs to decrease further within the next few years.

To measure carbon removal accurately, they employ multiple sophisticated techniques, from soil and water sampling to machine learning models that adhere to global standards. Their labs are in Darjeeling and Bengaluru, staffed by a team that includes PhDs, and they plan to expand their ground-based and remote sensing data collection efforts with the recent seed funding. Strategic partnerships with major players like Stripe, Meta, and Mitsubishi are helping them advance their mission, including signing an offtake deal with Japan’s MOL Group to buy 10,000 tons of credits soon.