The collapse of complex human societies remains poorly understood and
current theories fail to model important features of historical examples of collapse.
Relationships among resources, capital, waste, and production form the basis for an
ecological model of collapse in which production fails to meet maintenance
requirements for existing capital. Societies facing such crises after having depleted
essential resources risk catabolic collapse, a self-reinforcing cycle of contraction
converting most capital to waste. This model allows key features of historical
examples of collapse to be accounted for, and suggests parallels between successional
processes in nonhuman ecosystems and collapse phenomena in human societies.