The biggest problem in my view is the collapse of social standards and thus the relentless dysgenics that promote robots who can't really think their way through any unknown problem.
They form our elites, and are unable to respond to the disaster in front of them, and will be unable to respond as it gets worse.
However, I think that there's going to be workarounds for most of the big disasters, including the once-popular peak oil, resource shortages, etc. Even water shortage can be beat with a good desalination filter, which nanotech is about to provide (if my timetable is right).
The real problem, the big problem, is that society is falling apart. This isn't an external thing, but an internal one. People have nothing in common, no identity and thus are many selfish peasants tearing apart society like a giant cake, leaving nothing but crumbs.