Good point. Add to that the potential for economic chaos. Mathematically, it's textbook chaos theory. If there's more of a factor than can be handled, in chaos everything breaks down. It's the breakdown of governments and the associated wars and degredation of society that's the input that our civilization can't handle, so everything else runs amuck.
JMHO
Yep, interlocking crises can really multiply the effects. Imagine an Ebola outbreak in a city undergoing riots. Nobody sane will leave their house, and the economy will crash. Soon enough the engineers won’t report for duty at the power plants if it’s risky going back and forth, or if they are not paid (in meaningful money with purchasing power) due to the economic crash.