The setting is earth some year wayyyy in the future.
Because of runaway global warming caused by green house gas emissions planet earth became essentially uninhabitable; a giant ball of hot gas clouds. Everybody died.
Some alien race comes exploring for resources or whatever, but when they get here they find the planet is actually inhabited by the ghosts of all the angry souls that tried to warn people about our impending doom, along with some weirdly evolved flora and fauna maybe idk.
Obviously I haven’t fleshed out all the details, but it sounded like the seed of a cool idea so I wanted to share it and see what people thought before I forget I ever had it.
You might be interested in Apocalypse Hotel. Humanity has to evacuate Earth due to an environmental crisis. A hotel run by robots keeps running because that’s what the robots are programmed to do, and ends up becoming a hotspot for alien tourists. No ghosts though, the big mystery is what happened to the humans who left and whether they might someday return.