One thing that's always bothered me about the olivine methods (MgSiO3 + CO2 >> MgCO3 + SiO2) is that this is the same mechanism that is postulated to destroy th

One thing that's always bothered me about the olivine methods (MgSiO3 + CO2 >> MgCO3 + SiO2) is that this is the same mechanism that is postulated to destroy the biosphere (via carbon deprivation) in a few hundred million years. I'm not sure what the expectation is for re-release of the carbon on geological timescales, but it should certainly be investigated before these schemes are actually deployed.