The fragile world hypothesis is the hypothesis that 'if technological development continues indefinitely, systemic fragility will increase to the point that the possibility of a shock sufficient for complete collapse approaches certainty.'^[1]

Closely related to the concept of a 'global polycrisis':

Established concepts, such as “systemic risk” (Renn 2016; Renn et al. 2019), “catastrophic risk” (Bostrom and Ćirković 2008), or “existential risk” (Ord 2020) do not adequately highlight these crisis interactions, even though they do capture essential aspects of the phenomenon ...

A global polycrisis occurs when crises in multiple global systems become causally entangled in ways that significantly degrade humanity’s prospects. These interacting crises produce harms greater than the sum of those the crises would produce in isolation, were their host systems not so deeply interconnected.^[2]

An earlier version of the same paper^[3] described a global polycrisis as having three or more 'systems of origin' and involving 'Irreversible and catastrophic degradation of humanity’s prospects'.

A weaker version of this hypothesis is that such a collapse isn't inevitable, but is potentially as great an area of concern for longtermists as existential risk, due to the 'at a minimum, very difficult' nature of even a single technological reboot^[4] and the possibility of an increasingly difficult series of collapses and recoveries.^[5]

Not to be confused with the vulnerable world hypothesis.