but they will continue to come and go, regardless of our input

I'm not quite sure you understand the problem with climate change. It's not that "they" will come and go, it's that WE will only go. There's no "coming" back with any reasonable immediacy. Or were you arguing that the stones wouldn't be there for exhibition by the jellyfish that would be the only thing left living in the oceans?

Now, it is my opinion that when Brawndo finally pushes the climate over the tipping point and life as we know it takes its final breath, that natural selection will do what it has always done and though life will change, it will persist in some form. So were humans able to outlast this foreboding obstacle and humanity persists, then so be it, but I honestly doubt they'll give a shit about fucking stonehenge. If there were some life lessons from the past that only stonehenge can communicate, then it has obviously failed.