New study shows how environmental disruptions affected ancient societies

"Studying the factors that led to the advancement and contraction of past societies provides insight into how our globalized society might become more or less sustainable," Day said.

Day's collaborators include Joel Gunn of the University of North Carolina at Greensboro, William Folan of the Universidad Autonoma de Campeche in Mexico and Matthew Moerschbaecher of the Louisiana Oil Spill Coordinators Office. Gunn and Folan are Mayan archeologists and Moerschbaecher is a graduate of LSU's oceanography program.

With the human population having exceeded the capacity of Earth's resources, this analysis suggests that a transition toward sustainability for the current energy-dense, globalized industrial society will be very difficult if not impossible without dramatic changes.

The authors say that these past transitions were caused by a combination of social, astronomical and biogeophysical events such as volcanic eruptions, changes in solar emissions, sea-level rise and ice volume, biogeochemical and ecological changes, and major social and technological innovations. One example is the worldwide crisis that began in 536 AD, which was caused by three major volcanic eruptions within a decade. This event led to the destruction of half the population of Europe via the Black Death plague, starvation and wars. In China and the Mayan region, it led to crop failures, famine and plagues.

They found that when energy was abundant, societies expanded and prospered. Conversely, when energy sources declined, there was societal contraction and collapse. The previous example implies that changes are more likely to transpire due to planetary-scale disturbances and constraints, whether societal or environmental, and will likely lead to strong societal disruptions.

However, in the past, major changes sometimes moved toward a more sustainable social organization. For example, after one disruption, the Mayans switched to a more efficient use of energy and marine transportation and, at the time of European contact, they were leading a sustainable lifestyle.