Microsoft has signed a three-year agreement with Lithos Carbon to permanently remove CO₂ from the atmosphere through Enhanced Rock Weathering (ERW). By December 2023, Lithos Carbon had delivered 500 tons of carbon removal for Microsoft, deploying ultra-fine volcanic basalt rock dust on US farmland. Under the new agreement, Lithos Carbon will remove over 11,400 metric tons of CO₂ for Microsoft. As of August 2024, Lithos Carbon has spread hundreds of thousands of tons of basalt rock dust across nine states in collaboration with over 100 farmers, while collecting over 10,000 soil cores to validate carbon removal in new regions.
The agreement focuses on “ex-post” carbon removal, meaning the CO₂ has already been removed and rigorously quantified. Lithos Carbon will continue to refine its measurement techniques, validating not only the amount of CO₂ captured but the speed of removal. Their unique field-by-field approach is also generating agronomic and ecosystem benefits for farmers, supporting broader adoption in the carbon removal market.
Rock weathering naturally draws down an estimated 1.1 billion tons of CO₂ annually. By accelerating this process with basalt, Lithos Carbon shortens the carbon removal timeline from geologic millennia to human seasons. The basalt reacts with rainwater, locking CO₂ away for tens of thousands of years as bicarbonate, a key component of seashells. Lithos Carbon sources upcycled volcanic dust for this process, ensuring no new emissions are created.
ERW holds significant promise due to its permanence, scalability, and cost-efficiency for widespread agricultural adoption. Lithos Carbon’s data-driven research site, in partnership with experts from Yale’s Center of Natural Carbon Capture, is testing and validating carbon removal across 3,000 acres of farmland. The project compares various CO₂ removal measurement methods, with data to be made public for academic use, aiming to set new standards for transparency in carbon removal.
“Microsoft has been a worldwide leader in sustainability and we’re thrilled to work with them as a backer of our catalytic, data-driven project. Our mission is to work alongside farmers to transform cropland into carbon capture centers and remove a billion tons of CO₂ over a decade. This agreement represents a significant step in that direction with a commitment to increasing quantification and diligent measurement across large-scale commercial deployments. Our deal develops the system and technologies needed to scale outcomes-based carbon removal while responsibly stewarding our natural resources to enrich communities and agricultural land,” said Lithos Carbon’s CEO, Mary Yap.
For Microsoft, this partnership aligns with their goal of becoming carbon negative by 2030 while contributing to the growth of the carbon removal market.
“Supporting innovative solutions is central to Microsoft’s carbon removal strategy. Lithos Carbon’s dedication towards continued improvements in rigorously quantified Enhanced Rock Weathering systems and uncertainty reduction aligns with Microsoft’s pursuit of high-quality CDR projects, and we look forward to further advancements in Enhanced Rock Weathering,” said Brian Marrs at Microsoft.