Note that &quot;massive famine and likely fighting against other survivors&quot; will turn an apocalypse of the second sort <i>into</i> an apocalypse of the first sort.<p>I also think apocalypses that start out as the first sort are <i>also</i> likely to produce famines and fighting against other survivors; survivors will be desperate, and even though the population has declined, the infrastructure to support it (particularly, the <i>social</i> infrastructure, even if the physical infrastructure is untouched) will likely have declined <i>even more</i> than the population.