Bart, show me the math:
Show me in concrete figures that there can be an increase in any natural cycle which is let’s say a threefold and a fivefold over the past 55 years and still gives a fourfold increase in the atmosphere and a fourfold net sink rate together with the fourfold increase in human emissions.
And if you have the time: show me how that should affect the δ13C ratio in the atmosphere and the residence time.