I'm not too concerned about the megafuture issues. People (or robots) much smarter and vastly wealthier than us will find good ways to handle them.

I'm also not too worried about most of the potential near-future issues, like global warming and toxic waste and air pollution and deforestation. People moderately smarter and significantly wealther than us will solve them, in ways we can now only just barely realistically speculate about.

I'm mostly worried about the things that will make our near-term descendants dumber or poorer, depriving them of the resources to solve the problems they'll face. Things like trade barriers, obstacles to education/information/research/discovery, and malaria. The better we do at solving those problems now, the better our grandkids will do at solving environmental and ecological problems later.