Microsoft has signed a three-year agreement with Alt Carbon, an Indian startup based in Bengaluru, to purchase nearly 37,000 metric tons of carbon removal credits. The deal marks the tech giant's first enhanced rock weathering project in Asia and follows reports that suggested Microsoft had paused parts of its carbon-removal procurement program.

Under the agreement, Alt Carbon will deliver 36,920 metric tons of carbon dioxide removal credits by 2029 from its Darjeeling Revival Project. The company has issued nearly 10,000 carbon-removal credits through enhanced rock weathering to date and expects to issue another 15,000 credits by the end of the year.

Alt Carbon's project involves spreading crushed basalt on farmland in West Bengal, which reacts with rainwater and atmospheric CO2 to form stable bicarbonates. Discussions began in early 2025 and culminated after extensive scientific review and contract negotiations, making this a significant milestone for both companies.

The deal reflects the growing role of emerging-market suppliers in carbon removal, with developers from the Global South now accounting for about 26% of carbon-removal credit issuances. Alt Carbon plans to expand its deployment footprint fivefold over the next four to five years as demand for verified carbon-removal credits grows.