Okay, I know I should go do some research instead of writing an HN comment, but let's face it, I'm not yet a perfect person, so I haven't done that research, so

Okay, I know I should go do some research instead of writing an HN comment, but let's face it, I'm not yet a perfect person, so I haven't done that research, so here goes the HN comment instead. To be clear, my goal here is to provoke someone into convincingly explaining how wrong I am. What is the dilly with carbon sequestration? How can this make sense? Isn't this ideally mostly snake oil? Once upon a time (say 800 years ago?) we had huge quantities of carbon trapped deep below the surface of the earth (coal, oil, maybe I'm missing something else), AND ALSO huge quantities of carbon fixed in solids on the surface of the earth (large forests). Now we've taken as much coal and oil as we could find, and put it all in the atmosphere. Plus we've also chopped down lots of trees, and much of what was chopped down was burned. Let's just acknowledge that with 7 billion people needing food grown (not to mention living space), we as a race will not be replanting more forests than existed 800 (or even 100) years ago. At best, we'll replant some of them. So what happens to the carbon that's in the atmosphere from all the coal and all the oil? It won't be going into trees, will it?