NASA funded study says we are headed to civilization collapse
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).”
“The Human And Nature DYnamical model (HANDY) was inspired by the Predator and Prey model, with the human population acting as predator and nature being the prey. When small, Nature grows exponentially with a regeneration coefficient γ, but it saturates at a maximum value λ. As a result, the maximum regeneration of nature takes place at λ/2, not at the saturation level λ. The Commoners produce wealth at a per capita depletion rate δ, and the depletion is also proportional to the amount of nature available. This production is saved as accumulated wealth, which is used by the Elites to pay the Commoners a subsistence salary, s, and pay themselves κs, where κ is the inequality coefficient. The population of Elites and Commoners grow with a birth rate β and die with a death rate α which remains at a healthy low level when there is enough accumulated food (wealth). However, when the population increases and the wealth declines, the death rate increases up to a famine level, leading to population collapse.”
“We show how the carrying capacity —the population that can be indefinitely supported by a given environment [Catton, 1980]— can be defined within HANDY, as the population whose total consumption is at a level that equals what nature can regenerate. Since the regrowth of Nature is maximum when y = λ/2, we can find the optimal level of depletion (production) per capita, δ∗ in an egalitarian society where xE ≡ 0, δ∗∗(≥ δ∗) in an equitable society where κ ≡ 1, and δ∗∗∗ in an unequal society where xE ≥ 0 and κ ≥ 1.”
“In sum, results of our experiments, discussed in section 6, indicate that either one of the two features apparent in historical societal collapses —over-exploitation of natural resources and strong economic stratification— can independently result in a complete collapse. Given economic stratification, collapse is very difficult to avoid and requires major policy changes, including major reductions in inequality and population growth rates. Even in the absence of economic stratifica- tion, collapse can still occur if depletion per capita is too high. However, collapse can be avoided and population can reach equilibrium if the per capita rate of depletion of nature is reduced to a sustainable level, and if resources are distributed in a reasonably equitable fashion. ”
The whole cheery study can be read here