Collapse may refer to catastrophic failure:
https://en.wikipedia.org/wiki/Catastrophic_failurein turn leading to cascading failure:
https://en.wikipedia.org/wiki/Cascading_failureAn example is a collapse of, say, several oil companies due to peak oil, leading to catastrophic failure for one aspect of industrial societies (say, manufacturing output and JIT systems), which in turn is part of multiple crises including pollution and increasing population leading to cascading failure (high death rates) as part of limits to growth:
https://www.theguardian.com/commentisfr ... g-collapseThese are not based on "doom" but on physical laws, i.e., ecological footprint exceeding biocapacity, pollution impacting biocapacity, diminishing returns, etc.
There are crises that cannot be predicted easily, such as epidemics and pandemics (driven by combinations of mutations plus increased vectors in the spread of disease, such as urban or human migration, increased contact with wilderness areas, a breakdown in sanitation systems, etc.), wars (driven by increased arms production and deployment across more than three decades coupled with the fact that military forces need to justify spending), and more. Meanwhile, other crises, such as global warming and increasing debt, have parts that are predicable and others that are not (such as the relation between multiple feedback loops in the first and lack of regulation in the second). All of these may make cascading failure worse, in turn leading to multiple fast crashes, mainly because predictions about them logically go in the direction of increased crises.
Finally, perhaps the reason why combinations of crises amplifying each other leading to collapse should be taken seriously is because the global system involves combinations of complexity and bifurcation:
http://fleeingvesuvius.org/2011/10/08/o ... d-economy/