At what point do we begin to consider whether there is anything in the history of human civilization worth preserving for some future species that may either evolve here or arrive from elsewhere?
What would be worth preserving? How? Where? When should the planning and fund raising begin? Who should lead the effort?
Should we include a narrative of global history of some kind? Should we tell the truth about who we were or should we prevaricate? Are we capable of telling the truth about the collapse of our civilization?
Did we, among our various cultures and throughout our history on this planet, produce anything that would be worthy of long term preservation and that would be of interest to or informative for future species?
Or did we not? Perhaps we didn't when it comes right down to it and there's nothing to be done but wait and enjoy what can be enjoyed.
It's an interesting question.
Of course, we'll probably do no such thing. We'll just accelerate the destruction of the bio-sphere and count ourselves lucky to be so rich.