I predict we will be planting MORE crops in the future to feed the population and that will "fix" the carbon. That's the way God planned it. Less carbon, less food. Carbon is always moving in and out of the system, just as O2 is created from the carbon based plants.
I’ve head figures that if we were to reduce the CO2 to preindustrial levels, our food production would take a 12 to 13% hit and forest growth in the upper latitudes would decline by over 20%.