When we look over the longterm, Earth's main mechanism for atmospheric CO2 removal is through the weathering of silicate minerals. This cycle, known as the carbonate-silicate cycle is responsible for counterbalancing the CO2 released from volcanos. Rock storage of CO2 should not be relegated to a "Coming Attraction" because it is Earth's main event, with 99.94% of carbon on Earth currently stored as rock in the Earth's crust through this process. With about 46.6% of carbon in Limestones (CaCO3), 33.3% in Dolomites, and 20% in sedimentary carbon, and just .004% of carbon in the atmosphere, it becomes a no brainer, that we should store that carbon as rock as well (Dunsmore 1992, Berner and Lasaga, 1989).
Without any human intervention, each year silicate weathering removes nearly 1 gigaton of CO2 (Drawdown Website). This amount of CO2 removal would currently place the process at #69 on the list of Solutions. With only ~10-20% of land area being responsible for ~50-75% of the CO2 consumption through silicate weathering, we can consider most weathering to be considered "enhanced" by nature due to unique geological forces such as topography, temperature, and humidity.
This paper will look at the fastest weathering rates of silicates and basalt rock formations in nature, and how they can be enhanced even further. We will examine what it would look like for humans to match (and surpass) the 1 gigaton of CO2 removed by silicate weathering yearly, with a thorough examination of the economics and viability of the plan.
