I'd strongly suggest finding a source of predictions for the 50 to 100 year future made 50 to 100 years ago, from any source you care to look for, and enjoying the spectacle of just how completely absurd 99% of them were, then thinking much more carefully about your own predictions for anything that far ahead.The vast majority of such predictions made today, either by professional scientists, "forecasters" or laypeople all suffer from the same two core defects: 1. they're based far too much on current assumptions and worldviews. and 2. they completely fail at taking into account unknown unknowns, even if they claim not to do so. By definition they can't do otherwise anyhow.