A NASA-funded study “Human and Nature Dynamics” (HANDY) has created a model of how civilisations collapse that has created quite a stir in the community of people concerned about human threats to our current civilisation on “Spaceship Earth”. The report’s conclusion starts as follows:
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 strain placed on the ecological carrying capacity, and the division of society into Elites (rich) and Commoners (poor).