I would love to see vast herds of buffalo roaming parts of the Mid-West again, but too slow and it has limited potential. It doesn't affect all the coal and oil we burned, but rather just makes agriculture carbon-neutral. Then there's always the question of where you get the energy to do all that organic farming

ISAR’s research indicates that farmers growing these crops under carbon trading protocols could grow biomass representing up to 50 tons of net sequestered CO2 per acre (A) of cropland. These crops would produce revenues of approximately $50- $150/acres, thereby insuring grower’s adoption and enabling a smooth transition from conventional to IP agricultural practices. IP has the capability to absorb current total anthropogenic CO2 emissions (30,398 million tons CO2/year) through adoption of year- round IP production on 17% of the world’s arable cropland or through the growth and incorporation of ~4 tons/acre dry biomass on cropland worldwide.
The IP approach does not require high-tech equipment or have high costs for implementation. IP can be practiced in any country by farmers of any ability creating economic opportunities and bene ts worldwide, including third world countries. With the implementation of IP, valuable resources of energy, capital and captured CO2 would not be pumped into a “hole-in-the-ground” or to extreme ocean depths, but will be captured and incorporated into soils to improve the quantity, quality and health of farmland worldwide, while increasing crop yield and food quality.

Once you get the carbon in the farmland I don't think you can put a lot more in there. Natural processes in the soil make organic material decay and release CO2 back into the atmosphere. So you can offset all the anthropogenic CO2 for a few years and then you have great soil on every arable hectare and get no such additional carbon sequestration.