The fork in the road: how human societies respond to the threat of collapse

<p dir="ltr">In 250 years, globalisation and technological advancement have shaped human societies into systems nearly unrecognisable from anything that has come before. Environmental degradation, large-scale warfare, and technology have become existential threats to the whole human species. From this, a confronting question arises: Is it no longer possible to “learn from history?” Put more precisely, are the circumstances of the Twenty-First Century so different from the rest of history that the lessons from the past can no longer be applied in the present? </p><p dir="ltr">This thesis argues that meaningful lessons about how to deal with existential threats can still be drawn from the past and applied in the present, but that existing <i>Longue Durée</i> models are insufficient for doing so. I argue that these models focus too heavily on Eurasian agrarian societies that used currency and kept written economic records, creating a real risk that their conclusions cannot be applied in the present. The key innovation of this thesis is the use of the concept of complexity as a comparative tool to track the growth and decline of different human societies across the Longue Durée. Broken down into population, energy density per capita, number of institutional levels, and technological innovation, complexity can be established using environmental and archaeological data rather than requiring written evidence. This opens up many more human societies for comparative study. </p><p dir="ltr">The thesis contains six case studies of past human societies who faced the threat of collapse. Complexity is used to establish whether a society succeeded or failed in responding to the threat then more conventional historical source work is used to understand why. To offset the risk that conclusions about the past cannot be applied in the present, the case studies are diverse in population size, level of technological advancement, time period, and geographic location. If there are common historical processes between the hunter-gatherer societies of the Natufian and the Gunditjmara Nation, the agrarian societies of Old Babylonia and the Classic Maya, and the proto-industrial societies of Edo Japan and Qing China, then those processes are more likely to occur in the techno-industrial societies of the Twenty-First Century. If multiple societies operating in different contexts responded to the threat of collapse in similar ways and experienced similar outcomes, then it is more likely that those responses will produce the same results regardless of context. In contrast, if a response produced different outcomes for different societies, it is less likely to be relevant in the present. </p><p dir="ltr">As the fate of the world’s population becomes irrevocably intertwined, the stakes for getting the response to the threat of collapse right have never been higher. This thesis is more than a theoretical intervention, rather it aims to provide a simple way for analysing what works and what does not when dealing with large-scale existential threats. Its ultimate goal, then, is to develop a common language that facilitates conversation between specialists of different fields and time periods, and to provide a way for historians to present policy solutions to present-day decision-makers based on past events.</p>