But only a very miniscule fraction of carbon ends up as oil. This paper made an attempt at a comparison of fossil fuel use versus agricultural biomass producti

But only a very miniscule fraction of carbon ends up as oil. This paper made an attempt at a comparison of fossil fuel use versus agricultural biomass production: https://www.researchgate.net/figure/Global-annual-production-of-major-biomass-types-in-agriculture-and-forestry-and-fossil_fig1_240531181 https://www.researchgate.net/figure/Global-annual-production... I think plants convert 120 GtC from the atmosphere into biomass every year (ref https://www.worldbioenergy.org/uploads/Factsheet_Biomass%20potential.pdf https://www.worldbioenergy.org/uploads/Factsheet_Biomass%20p...) - obviously this is very roughly balanced by how much CO2 is naturally returned to the atmosphere. The additional anthropogenic CO2 emissions are 37 GtC. So there is theoretically enough biomass for us to sequester - if we could do all that work without dramatically increasing our CO2 emissions...