You're off by about two orders of magnitude there, judging from recent history. But even then, that's a long time from a human perspective, I think we could re

You're off by about two orders of magnitude there, judging from recent history. But even then, that's a long time from a human perspective, I think we could re-plant reefs the same way we replant forests on timescales of a couple generations or less. Edit: obviously it would be better if we didn't have to do that, but that ship has sailed.