I may be wrong, but I think user 22c may be trying to point out that we put an amount, W, of CO2 into the air by making the collective decision to fly so many planes in the first place.
> Marc Shapiro, the head of contrails at Breakthrough Energy, calls reducing contrails [...] the equivalent of removing carbon from the atmosphere at a cost of 10 dollars per ton or less
Contrail reduction and carbon sequestration aren't the same thing and it's not fair to equate them on cost.