GoKawiilStudy finds natural basalt weathering removes less CO2 than assumed
Researchers compiled river chemistry data from basaltic watersheds worldwide to recalculate how much carbon dioxide is naturally absorbed through silicate rock weathering. They found that critical zone processes—such as atmospheric deposition, hydrothermal contamination and secondary mineral formation—reduce the alkalinity that actually reaches rivers, meaning basalt weathering contributes a smaller share of global CO2 drawdown than prior estimates suggested, roughly 0.3% of annual anthropogenic emissions.
GoKawiil's interpretation of the reporting above, not reported fact.
This matters because basalt weathering is central to proposed enhanced weathering strategies for carbon removal, and if natural systems export less alkalinity than assumed, engineered approaches may need to account for similar losses. The findings suggest that scaling up basalt-based carbon capture could be less efficient than optimistic models imply, requiring more rigorous field validation before large-scale deployment.
- Global basalt weathering removes an estimated 0.084–0.180 Gt CO2 per year, about 0.3% of human emissions.
- Critical zone processes like hydrothermal inputs and secondary minerals reduce alkalinity actually exported by rivers.
- The results imply enhanced weathering carbon removal schemes may face similar efficiency losses in real-world conditions.
Hanna Instruments Alkalinity Checker HI775 — If reading about river alkalinity fluxes and basalt weathering makes you want to measure carbonate chemistry yourself, this pocket colorimeter gives a quick digital alkalinity reading instead of squinting at a color card. It's a handy, field-friendly way to track the same bicarbonate signal geochemists use to trace CO2 uptake, whether you're sampling a creek or dialing in an aquarium.
See Hanna Instruments Alkalinity Checker HI775 on Amazon → Affiliate link — we may earn a commission on purchases, at no extra cost to you. Product picked by AI based on this article; it is not a tested recommendation.Source: nature.com — Derry, 2026-08-26
Published there as: “Critical zone processes limit alkalinity export from natural basaltic systems”
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