Here is a slideshow of a presentation Prof. Olaf Schuiling did in 2010 on the SmartStones Foundation website.
Slide number four gives an overview on the distribution of carbon on our planet. I learned from that: Carbon contained in recoverable fossil fuel is only 0.005% of all carbon. The largest stores are limestones (46%), dolomites (33.3%) and sedimentary carbon (20%).
That’s where CO2 released into the atmosphere has gone over the whole history of the planet. And that’s where it should go right now. All we need to do is speed up the weathering process somewhat.