Following on my post above a natural extrapolation is for some bright spark to guesstimate just how many sqillions of megatonnes of Coal the earth holds in reserve. The do the same projections for what we have already extracted and burnt.
Then divide one by the other to work out approximately how much of that 60 million years of stored energy we have released "un-stored".
Is it 100 years; 1,000 years; 1,000,000 million years? If its anywhere up in the last one, then I think we are steadily marching towards serious atmospheric issues.