How much coal/oil/natural gas can be extracted largely depends on how much energy you put in to get the coal/oil/natural gas out from the ground by how much energy you will get out of it; its Net Energy. We will never extract every kilo of coal, every drop of oil, or every cubic metre of natural gas because there will come a day when you will use more energy to get it out of the ground than you will get from it. At that point, the source of energy is worthless. So jansenov, the answer for your question is that I don't know the exact quantities that will be extracted but I do know that a large percentage will be taken out.