There are two scenarios: a disaster that is bad, but from which humans can recover, and a disaster that ends us. The latter scenario is not entirely pointless: perhaps one day life will evolve again, or aliens will visit, and would it not be good for them to know we were here? It's a civilizational mark carved into the great Tree, "Humans were here." There are several interesting possibilities about how and where such a repository could be stored to survive through longtime, the best bet being the Moon, which is geologically inactive and quite extraordinary body, being large and the same angular size as the Sun as seen from Earth.

How would humans want to be remembered? We might focus on music, art, dreams, stories, philosophy, rather than technology, although that might be included, too. I suspect that zoology and biology would be particularly important, as this is the unique natural bounty of our world, the product of billions of years of Life living and dying.

This makes me want to write a story about how a world war begins over the selection of content of this Grand Time Capsule that kills us off.