01Why Enhanced Rock Weathering?
Natural weathering is slow. ERW tilts the balance — transforming CO₂ into stable minerals in soil to close the gigaton carbon gap.
FIELD 01 · BASALT ERW · ▮
Fertilizer that
puts CO₂ back in the soil
Finely milled basalt on cropland can lock >1 ton CO₂/ha/yr and improve soil health. Join us to scale the world’s most cost-effective carbon-removal solution.
Permanent storage
1,000×faster than natural weathering
001 · Solution
Enhanced Rock Weathering
Nature already removes carbon from the air. We make it happen at the speed the climate needs.
01
02How it works
Rainwater + CO₂ form carbonic acid → dissolves basalt → releases Ca & Mg ions → binds CO₂ as bicarbonate and carbonates.
03We speed up nature
By micronizing basalt and dispersing it across cropland, we boost weathering rates by ~1,000× versus natural rates.
04Soil & crop benefits
Instead of lime, we provide basalt minerals that buffer soil pH, add nutrients, and support healthier yields while removing carbon.
Field performance
0.84 t
CO₂ / ha / yr — median flux
15%
corn yield gain · 2025 EU plots
10,000+
years of stable storage
3:1
rock to CO₂ ratio
002 · Delivery
Carbondrop Matrix™ — Same Minerals, Smarter Delivery
Farm-Ready Deployment
Our hydrogel-based pellets anchor in the root zone and can be applied using standard farm equipment.
Nutrient & Water Retention Boost
We release Ca, Mg, K while improving water retention under dry conditions—adding agronomic value today.
Faster Carbon Mineralization
The hydrogel matrix optimizes basalt-soil contact, accelerating CO₂ → carbonate conversion.
Designed for Scale
Easy to store, bulk transportable, and capable of being spread with existing tools.
Field-Proven Carbon Removal
In trials: 0.7t CO₂/ha/yr on temperate cropland. At ~10% global farmland coverage, we unlock gigaton-scale impact.
Yield + Soil Gains
Demonstrated 15% corn yield in 2025 EU plots. Basalt adds essential nutrients and stabilizes pH.
Long-Term Permanence
Carbonates formed are stable for >10,000 years — no reversal risk, no buffer pools needed.
Low Energy Footprint
Grinding + transport uses ~25–40 kWh per ton CO₂. With mine-waste basalt, we estimate ~$100/ton CO₂ removal.
003 · Mission
Scaling Carbon Removal to Climate Relevant Levels
We are building an ecosystem-first carbon removal platform — enabling gigaton-scale CO₂ drawdown through soil-based solutions.
We partner with farmers across Europe to deliver climate impact and promote regenerative agriculture. Science is central.
Every project is measured, verified, and transparently reported.
004 · Process
We permanently lock away CO₂ with basalt-powered Enhanced Rock Weathering
01Sourcing Basalt Feedstock
Repurposing basalt mine waste
02Micronize Basalt Logistics
100 µm powder for rapid weathering
03GPS-Guided Field Spreading
Accelerating CO₂ to carbonate conversion
04Soil Sampling
Tracking pH and bicarbonate build-up
05MRV analyses
Measuring formed carbonates
06Data-Driven Field Insights
Remote soil data analytics
005 · Verification
High-integrity carbon credits
Built on measured geochemistry, not guesswork — every credit is real, permanent, and fully traceable.
Registration
Every credit is issued from a verified project and tracked through a digital registry from birth to retirement.
Verification
Independent MRV specialists review each project before any credits are generated.
Transparency
Project-level data is published openly, so buyers always know what they are paying for.
Permanence
CO₂ is mineralised into stable bicarbonates and carbonates that remain locked away for tens of thousands of years.
LCA Accounting
Emissions from sourcing, grinding, transport, and application are fully deducted from every carbon-removal claim.
Traceability
Field application, sampling, lab analysis, and lifecycle data are linked end-to-end for complete auditability.
Collaboration
We partner with farmers and researchers to scale verified carbon removal responsibly.
006 · Science
Built on measured geochemistry, not guesswork
Enhanced rock weathering is one of the most scalable carbon-removal pathways available today. We combine field measurements, geochemical tracers, and independent MRV so every tonne of CO₂ removed is traceable from atmosphere to mineral.
Rock to CO₂
Roughly three tonnes of finely milled basalt remove one tonne of atmospheric CO₂ — a well-characterised stoichiometry grounded in silicate weathering chemistry.
Measured, not modelled alone
Soil sampling, geochemical tracers, and process modelling are combined so every credit reflects real carbon locked away in the field.
Years of storage
Once dissolved as bicarbonate and carried to the ocean, CO₂ is stored in stable mineral forms for millennia.
The science behind it
Four years of weathering, on a timeline
In partnership with the Carbon Drawdown Initiative — the team behind one of the world’s longest-running, most heavily instrumented enhanced-weathering experiments.
1400days of daily data
One soil. Five treatments. Four years.
Twenty outdoor lysimeter pots, a single well-characterised soil, five basalt doses and 120 buried probes logging every day — one of the longest, most detailed enhanced-weathering datasets anywhere.
Read the series introBirchthe disturbance signal
The first big signal wasn’t weathering
The first storm washed out salts and woke dormant microbes — an alkalinity spike that appears in the unamended controls just as strongly as in the basalt pots. Early data is disturbance, not removal, so it’s screened out before any credit is claimed.
Read the articler = 0.70sensor ↔ leachate
The weathering engine, caught in the act
Warmer soil → more CO₂ → more carbonic acid → lower pH → more alkalinity. A buried 60 cm conductivity probe tracks leachate chemistry across every dose — proving the signal is measurable without a lab.
Read the article0.84 tmedian CO₂ / ha / yr
Measure, don’t assume
More basalt didn’t reliably mean more removal at this one pairing — and drainage, not temperature, is the master dial. Honest MRV means control-netting, depth-aware sensors, and admitting most sensors die in 2–3 years.
Read the article0104
Peer-reviewed literature
Carbon dioxide removal
CO2 & Atmosphere
- Rae, J. W. B. et al. Atmospheric CO2 over the Past 66 Million Years from Marine Archives. Annu. Rev. Earth Planet. Sci. 49, 609–641 (2021).
Climate Change
- Shukla, P. R. et al. IPCC, 2022: Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press (2022).
- The Climate Book. (Penguin Random House UK, 2022).
State of CO2
- Smith, S. M. et al. The State of Carbon Dioxide Removal - 1st Edition. (The State of Carbon Dioxide Removal, 2023).
Natural rock weathering
Natural weathering estimates
- Frings, P. J. Palaeoweathering: How Do Weathering Rates Vary with Climate? Elements 15, 259–265 (2019).
- Hartmann, J., Jansen, N., Dürr, H. H., Kempe, S. & Köhler, P. Global CO2-consumption by chemical weathering: What is the contribution of highly active weathering regions? Glob. Planet. Change 69, 185–194 (2009).
- Kasting, J. F. The Goldilocks Planet? How Silicate Weathering Maintains Earth “Just Right”. Elements 15, 235–240 (2019).
- Porder, S. How Plants Enhance Weathering and How Weathering is Important to Plants. Elements 15, 241–246 (2019).
- Renforth, P. The negative emission potential of alkaline materials. Nat. Commun. 10, 1401 (2019).
Weathering - silicate vs. carbonate minerals
- Liu, Z., Dreybrodt, W. & Liu, H. Atmospheric CO2 sink: Silicate weathering or carbonate weathering? Appl. Geochemistry 26, S292–S294 (2011).
- Palandri, J. L. & Kharaka, Y. K. A compilation of rate parameters of water-mineral interaction kinetics for application to geochemical modelling. Open-File Report (2004).
Enhanced rock weathering
Overview papers
- Hartmann, J. et al. Enhanced chemical weathering as a geoengineering strategy to reduce atmospheric carbon dioxide, supply nutrients, and mitigate ocean acidification. Rev. Geophys. 51, 113–149 (2013).
- Renforth, P. & Henderson, G. Assessing ocean alkalinity for carbon sequestration. Rev. Geophys. 55, 636–674 (2017).
Enhanced weathering field studies
- Almaraz, M. et al. Methods for determining the CO2 removal capacity of enhanced weathering in agronomic settings. Frontiers in Climate 4, (2022).
- Dietzen, C. & Rosing, M. T. Quantification of CO2 uptake by enhanced weathering of silicate minerals applied to acidic soils. Int. J. Greenh. Gas Control 125, 103872 (2023).
- Hamilton, S. K., Kurzman, A. L., Arango, C., Jin, L. & Robertson, G. P. Evidence for carbon sequestration by agricultural liming. Global Biogeochem. Cycles 21, (2007).
- Holzer, I. O., Nocco, M. A. & Houlton, B. Z. Direct evidence for atmospheric carbon dioxide removal via enhanced weathering in cropland soil. Environ. Res. Commun. 5, 101004 (2023).
- Knapp, W. J. et al. Quantifying CO2 Removal at Enhanced Weathering Sites: a Multiproxy Approach. Environ. Sci. Technol. (2023).
- Larkin, C. S. et al. Quantification of CO2 removal in a large-scale enhanced weathering field trial on an oil palm plantation in Sabah, Malaysia. Frontiers in Climate 4, (2022).
Enhanced weathering modelling studies
- Beerling, D. J. et al. Potential for large-scale CO2 removal via enhanced rock weathering with croplands. Nature 583, 242–248 (2020).
- Kantzas, E. P. et al. Substantial carbon drawdown potential from enhanced rock weathering in the United Kingdom. Nat. Geosci. 15, 382–389 (2022).
- Zeng, S., Liu, Z. & Groves, C. Large-scale CO2 removal by enhanced carbonate weathering from changes in land-use practices. Earth-Science Rev. 225, 103915 (2022).
- Andrews, M. G. & Taylor, L. L. Combating Climate Change Through Enhanced Weathering of Agricultural Soils. Elements 15, 253–258 (2019).
Carbon crediting
Carbon credits accounting
- Brander, M., Ascui, F., Scott, V. & Tett, S. Carbon accounting for negative emissions technologies. Clim. Policy 21, 699–717 (2021).
- Brander, M. & Broekhoff, D. Discounting emissions from temporarily stored carbon creates false claims on contribution to cumulative emissions and temperature alignment. SSRN (2023).
- Fridahl, M., Hansson, A. & Haikola, S. Towards Indicators for a Negative Emissions Climate Stabilisation Index: Problems and Prospects. Climate 8, (2020).
- Russel, S. Estimating and Reporting the Comparative Emissions Impacts of Products. (2019).
- Subke, J.-A., Kutzbach, L. & Risk, D. Soil Chamber Measurements BT - Springer Handbook of Atmospheric Measurements. in (ed. Foken, T.) 1603–1624 (Springer International Publishing, 2021).
007 · Questions
Questions & Answers
Everything you need to know about Carbondrop, enhanced rock weathering, and how we remove carbon at scale.
What is Enhanced Rock Weathering?
Enhanced Rock Weathering (ERW) is an approach that speeds up natural mineral weathering. Rainwater and atmospheric CO₂ form carbonic acid, which dissolves finely milled basalt and locks CO₂ away as bicarbonate and stable carbonates.
How does Carbondrop remove CO₂?
Carbondrop spreads finely milled basalt on cropland. The basalt reacts with CO₂ in soil water and converts it into dissolved bicarbonate, which eventually reaches the ocean and stays stored for millennia.
What is the Carbondrop Matrix™?
The Carbondrop Matrix™ is our hydrogel-enhanced basalt delivery system. It anchors basalt in the root zone, improves water retention, and can be applied using standard farm equipment.
Is the carbon removal permanent?
Yes. Once CO₂ is converted to bicarbonate and carbonate minerals, it is stable for more than 10,000 years with no reversal risk or buffer pools required.
What are the benefits for farmers?
Farmers see improved soil pH, added Ca, Mg and K nutrients, better water retention under dry conditions, and healthier yields while helping the climate.
How is carbon removal measured and verified?
Every project combines soil sampling, geochemical tracers, MRV analyses, and third-party verification. Project data is published openly on our MRV platform.
How can I get involved?
Contact us at peter@carbondrop.net to learn how your farm or organization can participate in verified carbon removal.
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