All the CO2 in the atmosphere weights on the order of 10^15 kg. That's roughly the size of a lake like the Titicaca lake. I did not do all the calculation as sodium formate is heavier than water but part of its weight is from added atoms (sodium and hydrogen) but that gives a scale of the room it would take. More likely, every country would have a few storage facilities, probably in closed down mines.
All the CO2 in the atmosphere weights on the order of 10^15 kg. That's roughly the size of a lake like the Titicaca lake. I did not do all the calculation as sodium formate is heavier than water but part of its weight is from added atoms (sodium and hydrogen) but that gives a scale of the room it would take. More likely, every country would have a few storage facilities, probably in closed down mines.