In 2024, the World Carbon Dioxide (CO2) counter climbed to 37.4 billion tonnes per year. All tracks to remove this greenhouse gas (GHG) from the atmosphere deserve to be examined. Among them, a simple, almost elementary idea: spread finely crushed rocks over agricultural land.
This name named enhanced rock weathering (ERW), or accelerated alteration of rocks would have the potential of Transforming both our agricultural practices and our climatic responses.
A natural process boosted by science!
The alteration of rocks is a Millennial geological phenomenon : under the action of water, air and microorganisms, some rocks react with CO2 and transform it into carbonates stablesstored in the soil or carried to the oceans.
THE silicate rocks like the basalt or theolivine are particularly effective. In them brushingwe increase their contact surface, which accelerates chemical reactions and therefore capturing CO2.
Unlike heavy direct capture technologies in the air, this method does not require fossil energy or industrial infrastructure massive. Better yet: her naturally integrates with agricultural practices. Indeed, she neutralizes soil acidity and can be applied as a Classic amendment.
But what about the field? This is precisely what studied Tyler Anthony And his team at the University of California, Davis. During three yearsthey tested different combinations ofAmendments, rocks, compostet biochar (a vegetable coal from wood waste pyrolysis), in arid meadows Browns Valley.
Trio gagnant
Research results, published in AGU Advancesare breathtaking: if the rocks alone have had a limited effect on carbon storage, the Synergy between compost, biochar and rocks to permis of Maximize CO2 sequestrationof Reduce nitrous oxide emissions (N2O) and ofImprove the absorption of methane (CH4).
Compost brings organic matter, biochar improves soil structure, and rocks catalyze chemical reactions.
According to the researchers, apply this mixture to Only 8 % of Californian meadows would remove up to 51.7 million tonnes of CO2 equivalent per year. And all this without harming agricultural production, quite the contrary.
Assault startups
This potential has attracted visionary companies. Eiona Californian startup, has established a partnership with Perdue AgriBusiness. Their bet is to replace agricultural limestone with theOlivine crusheda mineral capable of fixing CO2 while softening the floors. Thanks to the technique of soil fingerprintingthey can trace the quantities of carbon stored, to the trace elements such as the magnesium or the nickel.
For his part, Lithos Carbonbased in Seattle, values career residues by transforming basalt dust in amendment for farms. Thus, he manages to reduce the Environmental cost of transport and to capture about A billion tonnes of CO2 per yearaccording to its founder Mary Yap.
Not a magic wand, but a promising tool
Be careful Do not idealize this solution. Grinding, transport and spreading generate programs themselves, that must be minimize to guarantee a positive assessment. Also, there are other limits: the variability of soils, climates and rocks makes the results difficult to generalize.
This solution will not only take up the climatic challenge, but it deserves its place among the tools with high potential, provided that it controls its limits.
“It is essential to continue research in real conditions and to develop reliable measurement tools”underline the authors of the study.
The Mineral dissolution time remains slow, sometimes several years, and the Storage sustainability carbon, still uncertain.
Sources of the article
Anthony, T. L., Jones, A. R., & Silver, W. L. (2025). Supplementing enhanced weathering with organic amendments accelerates the net climate benefit of soil amendments in rangeland soils. AGU Advances. https://doi.org/10.1029/2024AV001480
Henry, L. (2025, avril 24). Rock dust that helps the climate: the agricultural bet against CO2. Science and life
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