I have corrected the explanation in the two paragraphs above. (slaw.ca)
Such estimates are analytically invalid; and they are in conflict with the more correct explanation given elsewhere in the same IPCC report: «This means that on average it takes only a few years before a CO2 molecule in the atmosphere is taken up by plants or dissolved in the ocean». (drtimball.com)
Given that the decision of what to feature on the mainpage is an indicator of general site opinion, I suspect this is a technically correct explanation to avoid being nailed for hypocrisy, but whatever. (sbnation.com)