Funnily enough, I’ve actually seen them before :)
Do you have a cite for any prediction of a *changing* rate of CO2 absorption before the missing CO2 was observed? Being wrong on a static rate is one thing, a bit too low, a bit too high, I can get it.
But when you had no idea that over time, the system would dynamically react to increased emissions, your mental model has missed something incredibly significant. Not the least of which is that it is possible that it would react to increased *sinks* as well, by providing extra sources to compensate.
Imagine if you will a buffer solution. One might predict that adding acid to a given solution will drive the pH down, and adding base will drive the pH up. But contrary to this naive expectation, with a buffer solution, both the acids are neutralized, and the bases are neutralized — the system reacts to drive the system to a set point, regardless of the external stimuli.
Stipulate for a moment that this is true about the CO2 in the atmosphere, and that it is in fact a system based on a set point, that reacts to both sinks and sources of CO2. To truly understand a system like that, you’ll need to go deeper into figuring out what is driving that set point, rather than what the sum total of sources and sinks are.