Enhanced Weathering

One promising method copies a process that has regulated Earth's climate for billions of years. Enhanced weathering spreads crushed silicate rock on farmland, where it reacts with CO2 and rainwater to form stable carbonates locked away for millennia.

The co-benefits are real: it removes atmospheric CO2, reduces soil acidity, and adds minerals that can lift crop yields. Modeling studies suggest it could remove up to about two billion tons of CO2 a year if applied across the world's farmland. The raw rock is abundant; the hard part is the logistics of crushing and spreading it.