Catastrophes have been happening for thousands of years. Read "Collapse" by Jared Diamond. He documents the collapse of a dozen significant civilisations, usual

Catastrophes have been happening for thousands of years. Read "Collapse" by Jared Diamond. He documents the collapse of a dozen significant civilisations, usually because they used up some other resource (water or wood for instance) required to feed themselves. It was also remarkable how quickly they self-destructed - usually within a few years, and often with evidence of cannibalism. Starving people don't play nice.