If the free oxygen in the atmosphere came from CO2 what happened to all the carbon?

Question

There is about 10E18 kilograms of free oxygen in the atmosphere and less than 10E16 kilograms of carbon fixed in molecules other than CO2 on Earth at this time. That logic only accounts for 1% of the free oxygen now in the atmosphere. So, where is the disconnect in the oxygen theory everyone believes is true and correct?

Answer 1

Much of the carbon is now trapped in limestone and other carbonates that were created by life in the sea. Today, corals and shellfish are creating more such carbonates. Trees and other plants only trap carbon for a short time, and then they die and decay and release the carbon dioxide back into the air. That is why planting trees does not help in the long run. But the lime stone and sea shells can last millions of years after the creature that made it is dead. Coral reefs are mountains of coral skeletons that have trapped in them lots of carbon.

Answer 2

Oxygen can also come from photolysis of water in the upper atmosphere; the hydrogen then diffuses upward and can escape into space.  This process would go much faster before there was an ozone layer to protect the lower atmosphere against UV.

It is believed that the water on Venus disappeared in this way.

Answer 3

total (carbon cycle) mass of carbon is close to 4.5*10^17 kg with much more located in the crust:

http://en.wikipedia.org/wiki/Carbon#Occu...

  - this is only counting carbon weight (12 amu) and does not include the additional weight of two oxygens (32 amu)

the weight of carbon needed to convert all that O2 to co2 would be:

(10^18)*(12/44) = 2.7*10^17 Kg