3 ms·They are mostly already oxidized.by ncmncm 5y agoThey are mostly already oxidized.eru 5y agoAnd it wouldn't matter too much (within reason): we have vastly more O2 in the atmosphere than CO2 we want to get rid of.ncmncm 5y agoThe CO2 is at <0.05% concentration. O2 is at >21%.