“Small societies are particularly vulnerable to disruption of key lifelines, such as trading relations, or to large perturbations like wars or natural disasters. Larger societies, with more diverse and extensive resources, can rush aid to disaster victims. But the complexity that brings resilience may also impede adaptation and change, producing social inertia that maintains collectively destructive behavior. Consequently, large societies have difficulty adapting to slow change and remain vulnerable to problems that eat away their foundation, such as soil erosion. In contrast, small systems are adaptable to shifting baselines but are acutely vulnerable to large perturbations. But unlike the first farmer-hunter-gatherers who could move around when their soil was used up, a global civilization cannot.”