As far as years go, we can do a lot better than AD 536, which by some historians’ standards revealed it was probably the “worst year in human history”.
Now, it seems it might not have been the worst thing, at least for the Ancestral Puebloan communities who occupied the southwestern US. In fact, the darkness of this brief, global ice age might have heralded a bright new day for their culture.
A study by a team of archaeologists and anthropologists from the University of California, Los Angeles and Colorado State University in the US revealed signs that the population spread throughout the Four Corners, not only recovered from a catastrophic climatic shift in the mid-6th century – In some areas they became stronger than ever.
To get a clear idea of why the year 536 CE was so difficult in most parts of the world, the Byzantine historian Procopius noted the time in his account of the Persian wars: “Because the sun gave off its light without shining like the moon during this whole year, and it looked more like the sun during the eclipse, because the beams that it shot were not clear or as they used to fall.”
Today, this sunscreen haze appears to have originated in a series of volcanic eruptions across the Americas, which throws enough ash into the atmosphere to turn summer into winter across much of the northern hemisphere.
Only five years later, a large part of the Roman population fell under an unparalleled plague. And another massive volcanic event, this time in El Salvador, produced more ash to top it all off.
Life in North America wasn’t much better. Measurements of tree rings from northern Arizona reveal a dip in temperature as the rains continue for decades.
However, archaeological records show that despite these difficult times, ancient Puebloans managed to develop a rich and complex culture that would thrive for centuries.
To get a clearer perspective on how established farming communities are coping with extreme and abrupt climate change, the researchers compiled a database of hundreds of food items and radiocarbon histories, all collected from 230 drilling sites across the region.
The ages, density, and locations of the agricultural products told an already familiar story to archaeologists, of a large population – divided into many smaller local settlements – practicing farming techniques suited to their local conditions.
Until about 400 AD, the land was a mixture of forage and farmers. Some were more than the latter, growing more important crops including corn and beans to supplement diets.
Significantly, by the sixth century, a sharp rise in population growth began to limit the amount of available farmland, as scattered groups of relatives were once keen to pack up and move around when opportunity arises.
By comparing the evidence for this cultural mixing in their database with climate records represented by tree rings from the Colorado Plateau, the researchers argue that there is a strong link between climate and cultural changes.
“Archaeologists have long recognized that demographic and social change transformed Ancestral Pueblo societies during the late 6th and early 7th centuries CE, but we contend that these changes are best understood when juxtaposed with the consequences of extreme cold at the beginning of this interval,” the team writes.
The hardships in the aftermath of AD 536 put the mix of emerging societies across the southwest to test. Some reorganized and developed the social and political relationships that have made their success. Others failed to thrive. In the end, the Hell Years were a selection process for cultural practices that could bring people together and allow them to share their experiences to get through tough times.
Within a few generations, the skies became clear again and the good times returned. Armed with new collaborative social practices, ancient Pueblo established a rich and resilient civilization that lasted centuries.
In the aftermath of many tremors, the ancient Pueblo always seemed to find a way to make a comeback, until they finally disappeared in search of new lands in the 14th century.
Even today, traces of their farming practices can be found in living cultures such as the Hopi.