Image: Dr. Dimitar Epihov
A nation by nation assessment published in Nature shows that adding crushed rock (finely crushed basalt) to farmland could absorb up to two billion tonnes of carbon dioxide from the air per year. The technique is called enhanced rock weathering and by-products of iron and stell manufacturing, and construction, could be processed to produce the rock dust needed. (H/T to Jenn for sharing this.)
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