Yes, crushed rock can indeed capture carbon dioxide from the atmosphere when spread on farmland—a process known as enhanced rock weathering (ERW). This innovative, nature-inspired technique accelerates a natural geological process to remove CO₂ while offering benefits to farmers and soils. As of March 2026, ERW is gaining traction as a scalable carbon dioxide removal (CDR) method with real-world trials and growing commercial interest.
How Does Enhanced Rock Weathering Work?
Over millions of years, rainwater naturally weathers silicate rocks like basalt, dissolving minerals and reacting with atmospheric CO₂ to form stable bicarbonate ions (HCO₃⁻). These bicarbonates wash into rivers and eventually oceans, where they can form carbonate minerals or remain dissolved for thousands to millions of years—providing durable, long-term carbon storage.
ERW speeds this up dramatically by crushing silicate rocks (often basalt from volcanic sources or mining by-products) into fine powder. The increased surface area allows faster reactions in soil:
• CO₂ dissolves in soil moisture to form carbonic acid.
• The acid reacts with rock minerals (rich in calcium and magnesium), releasing cations.
• These cations bind CO₂ into bicarbonate, which leaches safely into waterways and oceans.
The result? Atmospheric CO₂ is permanently removed, often for millennia.
Benefits Beyond Carbon Capture
ERW isn’t just about CO₂ removal—it delivers co-benefits for agriculture:
• Soil improvement — Crushed basalt neutralizes acidic soils, releases essential nutrients (like potassium, magnesium, calcium, and iron), and reduces the need for synthetic fertilizers.
• Higher crop yields — Studies show boosted productivity in various crops, with some field trials reporting increased growth even in challenging conditions like droughts.
• Additional environmental perks — It can lower soil acidity, protect against heavy metals, and in some cases reduce ground-level ozone or aerosols.
Farmers often view it as a win-win: subsidized rock spreading improves soil health while contributing to climate goals.
Real-World Potential and Latest Developments in 2026
Recent research highlights ERW’s promise. Global modeling suggests widespread adoption could remove 0.35–0.76 GtCO₂ per year by 2050 and up to 0.7–1.1 GtCO₂ per year by 2100—equivalent to offsetting emissions from major economies. In the U.S. alone, applying crushed basalt to farmlands could sequester 0.16–0.30 GtCO₂ annually by 2050, rising to 0.25–0.49 GtCO₂ by 2070.
Companies like UNDO, Lithos, and others are deploying at scale, spreading basalt on thousands of acres in the UK, US, Australia, and beyond. Tech giants (Google, Microsoft) have invested heavily, with pilot projects verifying removals and blockchain tracking for transparency.
Field studies confirm effectiveness: trials show 4–10 tons of CO₂ removed per hectare per year, depending on climate, soil, and rock type. Warmer, wetter regions (e.g., parts of the Global South like India and Brazil) offer faster weathering and higher potential.
Challenges and Realistic Outlook
While promising, ERW faces hurdles:
• Scalability — Sourcing enough suitable crushed rock (without massive new mining) remains a question, though mine waste and by-products help.
• Verification — Accurate MRV (monitoring, reporting, verification) is evolving, with costs and methods varying.
• Costs — Early estimates range from $50–$300+ per ton of CO₂ removed, potentially dropping to $100–150/t with scale and co-benefits (e.g., fertilizer savings). Some analyses suggest even lower figures in optimal locations.
ERW complements—not replaces—emission reductions. It can’t solve climate change alone but could play a major role in net-zero pathways.
In short, yes—crushed rock on farmland really can capture CO₂ through enhanced rock weathering. With ongoing advancements in 2026, this low-tech, high-impact solution is moving from promising research to practical deployment, helping fight climate change while supporting sustainable agriculture. If you’re a farmer, investor, or climate advocate, ERW deserves a closer look.