Enhanced rock weathering (ERW)-focused carbon removal project developer UNDO announced that it has signed a new agreement with Microsoft to permanently remove 28,900 tonnes of CO2 from the atmosphere by 2036 through an accelerated natural process 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. The company was recently announced as a $5 million winner in the XPRIZE Carbon Removal competition, aimed at catalyzing gigaton-scale carbon dioxide removal (CDR) solutions.

The new agreement marks the third between Microsoft and UNDO, including deals signed last year and 2023, and brings the commitment between the companies to nearly 49,000 tonnes of ERW-based durable carbon removal. Microsoft is by far the largest corporate buyers of carbon removal credits globally, with purchases exceeding 30 million tonnes, according to carbon dioxide removals (CDRs) platform CDR.fyi.

Phillip Goodman, Director, Carbon Removal Portfolio at Microsoft, said:

“Enhanced rock weathering is a promising pathway to gigatonne-scale carbon removal. UNDO’s commitment to scientific rigour gives us confidence in both the durability of these credits and their role in helping Microsoft achieve its goal of being carbon negative by 2030.”

Under the new agreement, 90,000 tonnes of crushed wollastonite spread across farmland in Canada. Wollastonite is a calcium-silicate mineral, with high calcium content allowing it to neutralize soil acidity and enhance soil fertility, and silicon content to enhance plant health, in addition to its carbon capture properties.

Alongside the new agreement, UNDO announced that its new deal with Microsoft is being supported by new  debt financing by Canadian climate fund Inlandsis, structured to provide the capital needed to deliver on the purchase, and with the scope to scale further high-integrity ERW projects globally.

Jim Mann, Founder and CEO at UNDO, said:

“Innovative financing is the catalyst for unlocking gigatonne-scale carbon removal. The support of Inlandsis shows how financial backers can help transform carbon removal into a genuine asset class – one that is scalable, tradable, and investable.”

David Moffat, Managing Director at Inlandsis, added:

“Inlandsis is very pleased to provide capital to this strategic and innovative deal, helping to strengthen the growing relationship between Microsoft and UNDO while advancing the critical fight against climate change.”