I sit in a hot office and think about this. I am not sure where to ask. I am genuinely curious. I have seen a breakdown of building solar panels to power the earth 2x over in order to recapture carbon equal to the rate it is being produced, but then areas of the earth that were reflective are now absorbtive of heat...
Had a similar thought. Not necessarily bamboo, but whatever plant offers the best time to carbon captured ratio. Then stash it in old mines (salt mines ideally), and flood the mines for additional assurance that decomposition won't happen. It doesn't scale well, I think, because you're dependent on the right conditions for storage, and creating storage places artificially doesn't sound like it would be very effective.