History repeats itself. Which means that we have an opportunity to learn from our mistakes, provided we know what our mistakes are. Recently, a set of factors have been discovered that forewarn of potential doom and gloom for a society. These factors preceded population crashes in Europe, yet could help us out in modern times.
By studying ancient civilizations, Dr. Sean Downey of the University of Maryland has developed a set of early warning signals (EWSs) for social systems. These EWSs were present in at least seven population collapses in Europe during the Neolithic era, between 4,000 and 8,000 years ago.
For his research, Downey studied nine regions in Europe that had been previously well studied. He used information from more than 2,000 archaeological sites that had over 13,000 individually dated artifacts.
All of the nine regions studied experienced at least one crash resulting in a loss of up to 60% of the regions population over the course of one century. Seven of those regions followed Downey's EWSs, while the remaining two regions were slightly more ambiguous, which means that each region's collapse was not spontaneous. There were definite factors involved in each collapse.
For example, in one area that is located in the basin of what is now Paris, Downey found that after agriculture was introduced, the region experienced a "boom" of steady growth lasting for about 1,2000 years. However, the region began to experience a "bust" about 6,255 years ago. EWSs were present almost 600 years before the bust began.
Each region experienced a steady population growth over the course of many centuries. The population growth was preceded by the introduction of agriculture. However, as the population of each region expanded, the people began to over-exploit resources.
One of Downey's EWSs is deforestation, which signals that a lack of resources was a contributing factor in each of the "busts." Nomadic civilizations were able to move once a region had been exploited, however agricultural civilizations were invested in their regions and unable to move once the region had been fully exploited.
When faced with the crisis, our ancestors would come up with solutions that were temporary in nature, yet had detrimental long-term effects. “Continuing on such unsustainable courses in the face of steady resource decline ultimately leads to catastrophic failure,” writes Downey in Proceedings of the National Academy of Sciences.