2. Enhanced Weathering using Cropland and Oceans
In essence this involves spreading pulverized ultramafic rocks on large areas of cropland, non-cropland and into the oceans. These rocks are rapidly weatherized, a process that involves the sequestration of atmospheric CO2 into a mineralized form which is stable for many years. This results in the removal of CO2 from the atmosphere and the silicon enrichment of the soil, improving crop yields and stress resistance. The products of weathering eventually reach the ocean and combat ocean acidification. In addition, this process decreases the production of N20 from the soil. N2O is also a greenhouse gas which warms the atmosphere 300 times more effectively than a comparable amount of CO2.
The use of EH techniques on the ocean or OAE (Ocean Alkalization Enhancement) will also be used to sequester O2 and reverse ocean acidification.

For further details see
-> 2. Negative Emission Technology
-> C. Enhanced Weathering