"If it gets cold, ice caps form, chemical weathering decreases, carbon dioxide accumulates in the atmosphere, which increases the greenhouse effect and surface temperatures. If it gets hot, the rate of chemical weathering increases, the rate of burial of sedimentary carbonates increases, the amount of carbon dioxide in the atmosphere and surface temperatures decrease," Dauphas said."
Does this or does this not sound like the C02 cycle acts as a natural thermostat on the atmosphere. During "cold" spells (ice ages) C02 accumulates in the atmosphere, which eventually produces a greenhouse affect, which produces a warm spell ("global warming"), which causes faster rate of the carbon sink affect, which decreases atmpospheric CO2 and temperature over time, leading to another "cold spell" which leads to another "warm spell", etc., etc., etc.
What then, if anything, can be the net "human affect" on this? It can only be the shortening of the time between the peaks and valleys of the cycle, and possibly addding the attainment of smaller peaks and valleys during those shorter cycles.
Which could mean, possibly, that any "warming" will end sooner than currently predicted, which will be followed by a cooling, which will only end in a shorter time if............we are still affecting the carbon release/carbon sink cycle.
If, instead, our activity increases the carbon sink during an upcoming warming (which reducing greenhouses gases will do), then the warming point in the cycle will last longer, and possibly reach higher temperatures before the atmospheric CO2 becomes high enough to trigger net additions to the carbon sink; that would bring in the cooling point in the cycle again.
Even if "human activity" is part of "global warming", the "global warming" political agenda could be the opposite of what we need to do; because of how C02 works as a natural thermostat. The warm cycles produce the C02 conditions leading to the next cool cycle and the cool cycles produce a C02 condition leading to the next warm cycle. The source (medium of exchange) is not important. Each cycle, cooling or warming, produces the C02 conditions for its reversal, based on the C02 balance, not how slowly or quickly it is obtained.