Geological carbon cycles and climate change 

Carbon dioxide reacts with other materials to form carbonate, such as calcium carbonate, CaCO3. These reactions reduce the amount of carbon dioxide in the atmosphere. Sedimentary rocks are formed from calcium carbonate and other materials. 

Over time, sedimentary rocks sink deeper underground where temperature is high. Under high temperature, calcium carbonate breaks down. The chemical reaction is 

CaCO3 = CaO + CO2

CaO, as a solid, stays underground. CO2, as a gas, is released back to the atmosphere, increasing its concentration. 

With tectonic activity, underground rocks rich in calcium oxide, CaO, may move to the surface. About fifty million years ago, the Indian subcontinent collided with the Eurasian tectonics, pushing up the Tibetan Plateau since. The exposed rocks, rich in calcium oxide and other materials with similar chemical properties, absorb large amounts of carbon dioxide in the atmosphere. 

The exposed calcium oxide reacts with carbon dioxide to form calcium carbonate. The chemical reaction is 

  CaO + CO2 = CaCO3

This process reduces the concentration of carbon dioxide in the atmosphere. This contributes to the decline of carbon dioxide and temperature in the last fifty million years.

Is the rise of the Tibetan Plateau a major drive of climate change in the last fifty million years? Are there some more significant factors at play?