A NASA-funded study says that the combination of population growth, wealth inequality and resource demand puts our current civilization at risk for collapse.

“There are widespread concerns that current trends in population and resource-use are unsustainable, but the possibilities of an overshoot and collapse remain unclear and contro- versial. Collapses have occurred frequently in the past five thousand years, and are often followed by centuries of economic, intellectual, and population decline. Many different nat- ural and social phenomena have been invoked to explain specific collapses, but a general explanation remains elusive. Two important features seem to appear across societies that have collapsed: (1) Ecological Strain and (2) Economic Stratification.

In this paper, the structure of a new model and several simulated scenarios that offer significant implications are explained. The model has just four equations that describe the evolution of the populations of Elites and Commoners, Nature, and accumulated Wealth. Mechanisms leading to collapse are discussed and the measure “Carrying Capacity” is developed and defined. The model suggests that the estimation of Carrying Capacity is a practical means for early detection of a collapse. Collapse can be avoided, and population can reach a steady state at the maximum carrying capacity, if the rate of depletion of nature is reduced to a sustainable level, and if resources are distributed equitably. ”

“Collapses of even advanced civilizations have occurred many times in the past five thousand years, and they were frequently followed by centuries of population and cultural decline and economic regression. Although many different causes have been offered to explain individual collapses, it is still necessary to develop a more general explanation. In this paper we attempt to build a simple mathematical model to explore the essential dynamics of interaction between population and natural resources. It allows for the two features that seem to appear across societies that have collapsed: the stretching of resources due to the strain placed on the ecological carrying capacity, and the division of society into Elites (rich) and Commoners (poor).”