Vaulted Deep’s technique is unique – instead of capturing carbon from the air, it collects organic waste and combines it into a thick slurry. This is then injected approximately 5,000 feet beneath the earth’s surface, permanently locking it away deep underground.

According to CEO Julia Reichelstein, this prevents the waste from decomposing in landfills or on land, which would release CO2 and methane, while also stopping pathogens from contaminating groundwater.

While the financial terms have not been disclosed, calculations based on the company’s current reported cost of $350 per tonne suggest the deal could be worth over $1.7 billion. However, Vaulted Deep expects its costs to decrease over time, and the actual price paid by Microsoft has not been confirmed, Tom’s Hardware reports.

This agreement is part of Microsoft’s broader strategy to offset the massive carbon emissions from its energy-intensive data centres. It follows another deal made in April with AtmosClear to sequester 6.75 million metric tonnes of carbon dioxide. The move reflects an industry-wide push, with firms like Google, Amazon, and Oracle also investing in carbon removal and exploring new energy sources, such as small modular reactors, to power their expanding operations.