I often think that contemporary humanity’s unsolved questions will not be bothering anyone in the future not because they will be solved and answered, but because they will be irrelevant.
Currently there are several types of vegetarians as far as I know. I’m interested in those who abstain from meat mainly because it’s morally wrong to kill animals (or indirectly participate in the killing). So we have a problem, some people like like to eat meat, and some find animal slaughtering abhorrent. There are different possible futures from here on. We stay with the status quo, so vegetarians are unhappy. We irrefutably prove that animals do suffer, agree on that that’s immoral and abandon livestock farming, so that meat-lovers are unhappy. There are better ways.
We advance technology to grow meats from animal stem cells. Or even 3d print them from vegetable proteins, although the first approach seems simpler. So now anyone can eat any meat she desires without feeling a littlest guilt for poor animals. Technically we won’t have to think whether raising and killing cattle is wrong, we won’t be farming so why bother. Same goes for fur, ivory and whatnot. Hopefully we can return overfished seas to more natural balance.
Or we can all upload or replace our bodies with machinery and only consume electricity.
As I think of it, getting gizmo-bodies or at least different biochemistry bodies can save us from lots of troubles. Diseases, ageing, hunger, inabilities etc. etc. Which reminds me that ability to self-modify is just ridiculously powerful. But such advances are not guaranteed to come within my lifetime unfortunately.
With rising interconnectedness of the global economy and people changing their countries more and more, state boundaries may become irrelevant too. We may mix up so thoroughly that any ethnic conflicts will be impossible.
On the other hand we can collapse the civilization and all at once escape problems of overpopulation, over-exploiting the environment, pollution and shortage or parking space.
Our descendants will have very different problems and questions to answer. For some time.