In a speech about climate change from April 4th of this year, UN General Secretary António Guterres lambasted “the empty pledges that put us on track to an unlivable world” and warned that “we are on a fast track to climate disaster”. Although stark, Guterres’ statements were not novel. Guterres has made similar remarks on previous occasions, as have other public figures, including Sir David Attenborough, who warned in 2018 that inaction on climate change could lead to “the collapse of our civilizations”. In their article, “World Scientists’ Warning of a Climate Emergency 2021”—which now has more than 14,700 signatories from 158 countries—William J. Ripple and colleagues state that climate change could “cause significant disruptions to ecosystems, society, and economies, potentially making large areas of Earth uninhabitable”.
Because civilization cannot exist in unlivable or uninhabitable places, all of the above warnings can be understood as asserting the potential for anthropogenic climate change to cause civilization collapse (or “climate collapse”) to a greater or lesser extent. Yet despite discussing many adverse impacts, climate science literature, as synthesized for instance by assessment reports of the Intergovernmental Panel on Climate Change (IPCC), has little at all to say about whether or under which conditions climate change might threaten civilization. Although a body of scientific research exists on historical and archeological cases of collapse, discussions of mechanisms whereby climate change might cause the collapse of current civilizations has mostly been the province of journalists, philosophers, novelists, and filmmakers. We believe that this should change.
Here we call for treating the mechanisms and uncertainties associated with climate collapse as a critically important topic for scientific inquiry. Doing so requires clarifying what “civilization collapse” means and explaining how it connects to topics addressed in climate science, such as increased risks from both fast- and slow-onset extreme weather events. This kind of information, we claim, is crucial for the public and for policymakers alike, for whom climate collapse may be a serious concern. Our analysis builds on the latest research, including Kemp et al.’s PNAS Perspective, which drew attention to the importance of scientifically exploring the ways that climate outcomes can impact complex socioeconomic systems. We go further by providing greater detail about societal collapse, for instance, distinguishing three progressively more severe scenarios. Moreover, we emphasize avoiding doom-saying bias and recommend studying collapse mechanisms in conjunction with successful adaptation and resilience, seeing these as two sides of the same coin.