Is there an estimation how much organic matter there is still in the ground?

Question

Oil, gas and coal are produced from organic matter. But is there an estimation how much is there still under the Earth's surface?

Answer 1

Definitively, no. Many resources I read give different numbers. If this information is needed for a school project, I would recommend searching for this at Google as there are numerous resources with some highly detailed graphs. Good luck in your search!