The period between roughly 5,000 and 3,000 years before present saw increasing climate variability in many parts of the Americas, including evidence for droughts in some regions and increased precipitation in others.

The El Niño-Southern Oscillation (ENSO) system, which drives significant climate variability across much of South America, was apparently more variable during this period than it has been in more recent millennia, creating unpredictable patterns of rainfall and drought that would have challenged the subsistence strategies of both hunter-gatherer and early agricultural populations.

Volcanic activity was also a factor.

The Eastern Cordillera of Colombia sits within the active volcanic zone of the Andes, and volcanic eruptions during the Holocene period would have periodically disrupted local environments.

The researchers noted that volcanic eruptions may have destroyed surface crops and pushed the Checua population toward reliance on underground food sources — tubers, roots, and other crops less vulnerable to ash fall and surface damage.