Nice graphic, but the ideal scenario would be to find a method that strips the carbon out of the CO2. We're putting about 50 Billion tons of CO2 into the atmosphere every year.
However, the Atomic weight of carbon is 12 whereas the Atomic weight of Oxygen is 16, and there are 2 oxygen atoms in every CO2 molecule, so 1 ton of pure sequestered carbon is 12+16+16 = 44/12 = 3 & 2/3 tons of CO2 removed from the atmosphere.
2.27 tons of carbon compacted together makes an approximately 1 meter cube.
Of course, that would mean we would have to sequester ~6 billion cubic meters (13.6 billion tons or the equivalent of 4,079 hoover dams in size, probably enough to resurface every highway and road in America 2-3 inches deep) of pure carbon every year to reach carbon neutral, and then we would need to go beyond that to begin to reverse the effects.
It would literally be the largest human undertaking in the history of the planet.
While it seems enormous, it's a very small fraction of the world.