A UK-based enhanced rock weathering (ERW) company has solidified its position in the carbon removal sector with the signing of its third and largest carbon dioxide removal (CDR) agreement with Microsoft. The new deal commits to delivering 28,900 tonnes of carbon removals by 2036, supported by debt financing from a Canadian climate fund. This agreement highlights Microsoft's ongoing investment in emerging technologies that are critical to meeting its ambitious goal of becoming carbon negative by 2030 and removing all historic emissions by 2050.

Enhanced rock weathering is increasingly recognised as a promising natural carbon sequestration method. It involves spreading finely crushed silicate rocks, such as basalt or olivine, over agricultural lands where these minerals react with atmospheric CO₂, accelerating natural weathering processes and locking carbon into soils and oceans over long periods. The UK firm's latest deal aims not only to contribute to carbon sequestration but also to advance the practical application and scalability of ERW technologies.

This deal follows Microsoft’s previous commitments to ERW, including a 12,000-tonne CO₂ removal agreement with Terradot from 2026 to 2029, which included funding for scientific monitoring aimed at building a stronger empirical understanding of ERW’s effectiveness at scale. Similarly, UNDO became Microsoft’s first ERW supplier by providing mineral-rich basalt rock for agricultural soil in the UK, designed to permanently remove approximately 5,000 tonnes of carbon dioxide over 20 years. These partnerships underscore Microsoft’s strategy of integrating both commercial deployment and scientific research in carbon removal initiatives to ensure credibility and impact.

The growing interest in ERW is also evident beyond Microsoft’s sphere. Frontier, a carbon capture buying consortium, inked a significant $33 million offtake agreement with American ERW firm Eion to secure the removal of 78,707 tonnes of CO₂ between 2027 and 2030. Eion deploys olivine across the US Midwest and Southern regions, capitalising on its fast-reacting properties to accelerate carbon sequestration in soils. Internationally, Mitsubishi Corporation and Alt Carbon have partnered to scale ERW carbon removal in South Asia, aiming to produce high-quality and durable carbon removal tonnes while promoting sustainable agricultural practices in the region.

While the fundamentals and scientific basis of ERW are gaining traction, industry stakeholders stress the importance of robust data and monitoring to better quantify removals and the environmental co-benefits, such as soil health improvement. Microsoft and its partners’ multi-pronged approach — combining commercial contracts, scientific research, and diverse geographic applications — exemplifies how ERW might mature into a critical tool in the global climate mitigation arsenal.

As the various agreements illustrate, enhanced rock weathering is evolving into a key sector within voluntary carbon markets and climate-tech innovation. However, the technology remains nascent, and its long-term scalability and efficacy will depend on continued scientific validation, regulatory frameworks, and effective deployment strategies, particularly in diverse ecosystems worldwide.

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Source: Noah Wire Services