There are a lot of disaster movies out there, usually featuring some kind of massive population collapse. I've been wondering about "What happens afterwards?" For a short enough disaster, I'd imagine a reasonable (albeit slow) recovery would be possible as there'd still be plenty of people left from before the fall with useful knowledge and much of the infrastructure would still be usable/salvageable.
But, if civilization experiences a long drawn out catastrophe (one with large population loss), is there some point where things are unlikely to either reach the same level again or even get started in the first place? Seeing as most of the "easy" resources have already been used up and much modern knowledge lost over the centuries. I mean, a lot of development came on the back of cheap coal and oil (and iron, and copper and etc.) but much of the easily mined reserves have since been extracted and I'm not sure how much you could realistically scrounge from a crumbled centuries abandoned megacity.
So basically, does a modern advanced civilization (i.e. Earth 2017) really only get one chance to get started? If we fail, could we ever get going again?