Complexity, problem-solving, sustainability and resilience

Societies often solve problems by developing more complex technologies and institutions. Sustainability emerges from success at solving problems. Complexity is a powerful problem-solving tool, but increased complexity requires resources and carries a metabolic cost. Resilience, a condition of vulnerability or the capacity to recover from a setback, helps achieve sustainability goals. Resilient societies must have reserve problem-solving capacity to adjust to major challenges. The abilities of ancient and modern societies to respond to crises at different states of complexity illustrate the relationship between problem-solving capacity and resilience. Increasing complexity, effective at first, seems inexorably to accumulate and to evolve to diminishing returns, undermining the ability to solve future problems. These processes are illustrated through historical case studies, including urban resilience.