Why would carbon need to go back into the ground? It’s really good for plant life in general and only bad for humans who want the earth to remain in the same state it was in 1700 indefinitely.
A follow-up species in a few million years might struggle to bootstrap theirs.
But if we're talking about a second industrial revolution it won't be like the first one, because:
- There will be more carbon in the air, hence more wood to chop and burn
- There will books lying around describing how to leapfrog many steps
I don't think it'd take 10000 years again to restore civilization the second time around.