What will earth become over the next 100 years?
How much longer will the oceans be a source of food?
When will the US break up into different nations?
Can humans survive nuclear war?
Will socialism replace capitalism?
Is a reset inevitable?
Concerning the state of human knowlege...
Over the years, on this forum these have been my top picks for what humanity will discover in the next century:
Physics - Questions to be Answered
1. What is dark energy?
2. What is dark matter?
3. Why is there an arrow of time?
4. Is there a grand unified theory of forces?
5. Are there parallel universes?
6. Why is there more matter than anti-matter?
7. What is the fate of the universe?
8. Why does the quantum wave function collapse?
9. Is string theory correct?
10. Is there order in chaos?
Origin of Life - Questions to be Answered
1) The origin of life may have been a miracle.
2) The origin of life was an event fully consistent with chemistry and physics, but one that was almost infinitely unlikely and required an improbable sequence of numerous steps.
3) The universe is organized in such a way that life is an inevitable consequence of chemistry, given an appropriate environment and sufficient time.
Archaeology
Discovering Tomb of Genghis Khan
Discovering Alexander the Great’s tomb
Deciphering the lost language of the Indus Valley civilization