> I’m guestimating we have about 1/3 of that which needs to be pulled out to correct for emissions to this point.

For the moment, that’s a slight overestimate; we’re a little over 400ppm, and pre-Industrial levels were about 300ppm, so we “only” need to remove 1/4 (and we don’t really need to go back all the way to preindustrial levels, it was about 325ppm in 1970)