This is not correct. You have to account for reversing all of the profligate methane producing swampland, turning it back into swampland, to fully account for

This is not correct. You have to account for reversing all of the profligate methane producing swampland, turning it back into swampland, to fully account for this as part of the calculation. We've done planetscale engineering already by how much methane we've reduced by converting swamp to farm/urban land.