Too much inequality and too few natural resources could leave the West vulnerable to a Roman Empire-style fall.
Few think Western civilization is on the brink of collapse—but it's also doubtful the Romans and Mesopotamians saw their own demise coming either.
If we're to avoid their fate, we'll need policies to reduce economic inequality and preserve natural resources, according to a NASA-funded study that looked at the collapses of previous societies.
"Two important features seem to appear across societies that have collapsed," reads the study. "The stretching of resources due to the strain placed on the ecological carrying capacity and the economic stratification of society into Elites and Masses."
In unequal societies, researchers said, "collapse is difficult to avoid.... Elites grow and consume too much, resulting in a famine among Commoners that eventually causes the collapse of society."
As limited resources plague the working class, the wealthy, insulated from the problem, "continue consuming unequally" and exacerbate the issue, the study said.
Meanwhile, resources continue to be used up, even by the technologies designed to preserve them. For instance, "an increase in vehicle fuel efficiency technology tends to enable increased per capita vehicle miles driven, heavier cars, and higher average speeds, which then negate the gains from the increased fuel-efficiency," the study said.
The researchers used what they termed a Human And Nature DYnamical (HANDY) formula to reach their conclusions. The formula uses factors such as birth rates, resources, and income classes to create a mathematical equation to project outcomes.
The study was sponsored by NASA's Goddard Space Flight Center and headed by the National Science Foundation's Safa Motesharrei.
For those who think modern society is immune from the problems that brought down ancient civilizations, a "brief overview of collapses demonstrates not only the ubiquity of the phenomenon, but also the extent to which advanced, complex and powerful societies are susceptible to collapse," the study said.
So how do we save ourselves? "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," reads the report.