NASA: National Aeronautics & Space Administration
2012&14 Nasa-Funded Studies: Human (Predator) and Nature (Prey) Dynamics (HANDY) studies
The Human and Nature Dynamics (HANDY) studies were – conducted by (a) Safa Motesharrei, School of Public Policy, Univ of Maryland; sponsored by US National Science Foundation-supported National Socio-Environmental Synthesis Center; (b) Jorge Rivas; Dept of Political Science, Univ of Minnesota; (c) Eugenia Kalnay, Dept of Atmospheric and Oceanic Sciences, Univ of Maryland. [Seminar of Study]; and “partially funded through NASA/GSFC [Goddard Space Flight Center] grant NNX12AD03A”; although NASA allegedly does not officially endorse the studies conclusions.
Human And Nature DYnamics (HANDY) is based on the Alfred Lotka and Vitto Volterra predator-prey model, which described the dynamics of competition between two species; in that case wolves and rabbits. In these HANDY studies humans are considered the “predator”, while nature (the natural resources of the surrounding environment) is considered the “prey”, depleted by humans.
Predation: Predator-Prey and parasite-host involves interactions in which one organism consumes all or part (resources) of another. These linkages are the prime movers of energy through food chains. They are an important factor in the ecology of populations, determining mortality of prey and birth of new predators. Predation is an important evolutionary force: natural selection favors more effective predators and more evasive prey. “Arms races” have been recorded in some snails, which over time become more heavily armored prey, and their predators, crabs, which over time develop more massive claws with greater crushing power. Growth-Collapse predator-prey systems are potentially unstable; as opposed to Keystone Predator Ecoystems.
Humans who engage in totalitarian agriculture, engage in Predator-Prey Growth and Collapse of Civilization/Empire cycles: Greco-Rome, Minoan, Mycenaean, Sumerians, Akkadian, Assyrian, Babylonian, Achaemenid, Seleucid, Zhou, Han, Tang, Song, Parthian, Sassanid, Umayyad, Abbasid, Mauryan, Gupta, Maya, Hittite, Harrapan and Teotihuacan. Collapses result from (1) Ecological Strain and (2) Economic Stratification and include the disappearance of between 90-99% of the populations (from famine, disease and organized violence resource wars) including their kings, Gods, calendars and other complex political and cultural institutions.
Economic Stratification Collapse occurs due to unequal consumption of resources generating Elites vs Commoners. As Elites become sizable and keep growing, they consume more; their over-exploitation results in collapse of resources to the Commoners; who experience famine and collapse. Elites — due to their wealth — do not suffer the detrimental effects of environmental collapse until much later than Commoners, which allows them to continue ‘business as usual’, despite the impending catastrophe; explaining how historical collapses were allowed to occur by seemingly oblivious elites (eg Roman & Mayan cases).
2012: Abstract: A Minimal Model for Human and Nature Interaction:
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 controversial. Collapses have occurred frequently in the past five thousand years, and are often followed by centuries of economic, intellectual, and population decline. Many different natural 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 equally.
PDF: 2012: Motesharrei Rivas Kalnay: Minimal Model for Human & Nature Interaction
2014: Abstract: Human and Nature Dynamics (HANDY): Modeling Inequality and Use of Resources in the Collapse or Sustainability of Societies:
There are widespread concerns that current trends in resource-use are unsustainable, but possibilities of overshoot/collapse remain controversial. Collapses have occurred frequently in history, often followed by centuries of economic, intellectual, and population decline. Many different natural and social phenomena have been invoked to explain specific collapses, but a general explanation remains elusive.
In this paper, we build a human population dynamics model by adding accumulated wealth and economic inequality to a predator-prey model of humans and nature. The model structure, and simulated scenarios that offer significant implications, are explained. Four equations describe the evolution of Elites, Commoners, Nature, and Wealth. The model shows Economic Stratification or Ecological Strain can independently lead to collapse, in agreement with the historical record.
The measure “Carrying Capacity” is developed and its estimation is shown to be a practical means for early detection of a collapse. Mechanisms leading to two types of collapses found in history. Collapse can be avoided, and population can reach a steady state at maximum carrying capacity if the rate of depletion of nature is reduced to a sustainable level and if resources are distributed equitably
PDF: 2014: Motesharrei Rivas Kalnay: Human and Nature Dynamics (HANDY)