Did you read this?
CO2 in ice cores.
Don't get me wrong, I think CO2 re-absorbtion after a spike in concentration is an interesting question. Given that the problem in question is emission though, I think it's a bit disingenuous to only focus on that issue.
It almost seems to be that you're saying there could be some as-of-yet unknown mechanism that will kick in and absorb all this carbon (any time now) quicker than we can emit it, so it's silly to worry about it.