Microsoft announced a new purchase agreement with enhanced rock weathering (ERW)-focused carbon removal project developer UNDO, for the permanent removal of 15,000 tonnes of CO2 from the atmosphere using rocks and soil.

Founded in 2022, London-based UNDO develops carbon removal projects based on enhanced rock weathering. The company’s technology accelerates the natural geological process of weathering by spreading crushed silicate rock onto agricultural land, where plants and microbes in the soil speed up the weathering process, removing CO2, while simultaneously enriching soil with essential nutrients. According to the company, the process has the potential to scale rapidly to permanently remove billions of tonnes of carbon dioxide.

The announcement follows an initial agreement in 2023 between the companies for the removal of 5,000 tonnes of CO2, by spreading 25,000 tonnes of crushed basalt across agricultural soils in the UK. Under the new agreement, UNDO will spread 65,000 tonnes of crushed basalt and wollastonite across the UK and Canada, removing 15,000 tonnes of CO2.

UNDO said that the agreement will also help fund research in the ERW field, enabling the company to set up field trials and monitoring sites for research into measurement, reporting and verification (MRV) of ERW-based carbon dioxide removal.

Jim Mann, CEO and Founder of UNDO, said:

“This agreement with Microsoft is a clear signal to the market that enhanced rock weathering has potential to deliver scalable carbon removal, and that UNDO can deliver critical scientific research to instil more confidence in this vital climate tech. We are eager to continue our work advancing the science of enhanced rock weathering by scaling up our research and data-gathering capabilities, which will be greatly facilitated by Microsoft’s continued backing.”

The agreement marks the latest in a rapidly growing series of carbon removal deals for Microsoft, forming part of the tech giant’s initiative to become carbon negative by 2030, which span an increasing range of solutions and technologies including, direct air capture (DAC), ocean-based carbon removal, and biochar-based projects, and include several large-scale nature-based and BECCS-based carbon removal deals.

Brian Marrs, Senior Director of Energy Markets at Microsoft, said:

“Microsoft is committed to being carbon-negative by 2030. We are excited to support UNDO’s enhanced rock weathering carbon removal projects with co-benefits for soils, farmers, and rural communities. With this follow-on deal, we look forward to working with the UNDO team who will pioneer further deep science across different measurement techniques and at varying scales to deliver crucial ERW process data.”