The flux of sediment from an undisturbed drainage basin changes over the short-term as rainstorms come and go, individual hillslopes fail in mass movements, and riverbanks collapse.
Over the long-term, the flux of sediment from a drainage basin oscillates around a mean value, producing a dynamic steady state, unless there are significant changes in boundary conditions such as climate, vegetation cover, or uplift rate.
[1] An example of this condition is deforestation combined with agricultural land conversion, this increases the fluvial sediment flux to a new and higher dynamic steady state because soils are now disturbed by plowing and thus more vulnerable to erosion.
If at any point over this time span the concentration of carbon dioxide had dropped to less than 1/3 of its present value, almost all photosynthesis would have stopped, but the records show that this has not happened.
The conclusion that the long-term circulation of materials of the earths surface environment can be regarded as a dynamic system, protected from severe perturbations by effective feedback mechanisms and without major secular trends, seems reasonable.