The story of early European settlement in the Americas is a pretty catastrophic one for native communities, involving widespread depopulation as a result of disease and violence. However, while classic understandings of this encounter tend to describe a process of almost instantaneous and ubiquitous destruction, a new study has revealed some fascinating insights that point to a re-telling of the story.

Appearing in the Proceedings of the National Academy of Sciences, the new paper reveals how the effects of European arrival in the Americas may have been staggered and unequal rather than universal, with some areas experiencing very little change for long periods after initial contact had been made. This, in turn, carries a number of implications regarding the climatic consequences of post-Columbian interactions, challenging several theories that link the destruction of native populations to the development of the Anthropocene.

According to these models, a sudden drop-off in indigenous inhabitants throughout the Americas resulted in significant regrowth of trees in areas that had been deforested to accommodate villages. This then led to substantial carbon sequestration – whereby trees remove carbon dioxide from the atmosphere – and has been proposed as a potential cause of global cooling, leading to the Little Ice Age.

Yet this has all been challenged by a team of researchers led by Matthew Liebmann of Harvard University, who conducted a detailed analysis of former settlements in the Jemez Province, New Mexico. By combining archaeological techniques with dendrochronology – the study of tree rings – and an analysis of historical records, the team sought to determine how populations were affected in the years following the arrival of Europeans, and how this altered the local environment.

According to their findings, populations remained stable in the Jemez region from when the Europeans arrived in 1492 until 1620, yet over the next six decades numbers plummeted by 87 percent. While these villages had been among the first in the Americas to encounter European colonizers, their sudden destruction did not occur until the first missionary settlements were established in the area. This suggests that indigenous populations were not wiped out in a single unstoppable wave of disease immediately after the Europeans landed, but instead were destroyed only once sustained daily interactions began.

Speaking to IFLScience, Liebmann explained that, because this occurred at a different point in time for each native community, it’s much more likely that depopulation occurred “in a mosaic pattern.”

^{The rapid destruction of indigenous populations in the Americas had been linked with climate change, although Liebmann's study suggests the story may have been more complicated. Janaka Dharmasena/Shutterstock}

“Our article challenges that old notion that disease swept through the Americas almost instantaneously,” he says. “It’s not that we disproved that earlier model, but our data complicates things a little, so people should pause before projecting these models of depopulation over the entire hemisphere or continent.”

The paper also describes how a significant regrowth of ponderosa pine trees occurred throughout Jemez as local populations disappeared. This facilitated the spread of forest fires, which subsequently became more frequent.

What impact this had on the environment is hard to predict, since one cannot assume that the same changes were occurring across the Americas at the same time.

“Depopulation could have amplified the climate changes that were already underway, but making this connection was easier when you could just assume depopulation was happening all over and then say ‘yes, that lines up exactly with the global dip in carbon dioxide.'”

Warning against projecting the findings from Jemez across the Americas as a whole, Liebmann says he is “not writing off depopulation as a cause of climate change, but we need to be a little more cautious about doing these kinds of global or hemispheric estimates.”