The end of the graph was cut off.  You can see the whole thing here:

http://www.unc.edu/~nielsen/soci011/hs13/hs13001.gif

I think it's clear that human ingenuity alone is not enough to overcome resource limits.  Cheap energy from petroleum and the technology we've made from it has sheltered us from the dieoffs we used to suffer regularly in the past.

The Black Death may not be entirely unrelated to population.  Bubonic plague existed for millennia in Europe and Asia; why did it suddenly become a pandemic?  Some researchers believe that it was because rapid population growth left people vulnerable.  Many were suffering malnutrition, weakening their immune systems.  Others even argue that the Black Death was several different diseases, all spreading because the population was vulnerable due to insufficient food.

This article explicitly links the Black Death with the Great Famine that preceded it.  It also argues that the shortage of firewood caused by the growing population created hygiene problems; heating water for baths in winter became a luxury only the wealthy could afford.  

I suspect that many of the seemingly random "events" we see as separate from energy issues are not.  War and disease are much more likely when there's too many people and not enough resources.  

I agree that a sense of history is very important to set events in context. There's some suggestive evidence that the Dark Ages may be been precipitated, at least in part, by an ealier, and larger, erruption of Krakatoa than the one documented in 1883. It seems that subduction zone hot spot errupted in about 535 AD and may have lowered global temperatures enough to stress the existing social structures, although nothing like as much as the Toba erruption would have. For further information see the book Krakatoa by geologist Simon Winchester.