I would like to propose Futurology.SE.
In Futurology we should talk about possible futures of humanity, the earth and the universe, possible existential threats and how humanity should deal with them, possible challenges we should overcome in the future, etc. I do not believe this has been covered by Worldbuilding.SE since it is more focused on fictional worlds as opposed to the real world in the future.
I know this has been deleted before but I want to propose it again. I do not know how to do so, though.