How Humans Made Fire in Brutal Cold Tens of Thousands of Years Ago

Exceptional new findings from Ukraine have solved part of an archaeological mystery that has long puzzled scientists – how did our ancestors manage to survive the harshest period of the last Ice Age when temperatures plummeted to extremes rarely seen in human history?

An international research team led by the University of Algarve and University of Vienna has uncovered rare evidence of sophisticated fire use from the coldest phase of the last Ice Age in Europe, a period when temperatures were so severe that many regions became uninhabitable.

“Fire was not just about keeping warm; it was also essential for cooking, making tools and for social gatherings,” explains Philip R. Nigst, one of the lead authors and an archaeologist at the University of Vienna.

The groundbreaking research, published in the journal Geoarchaeology, analyzed three ancient hearths at Korman’ 9, a prehistoric site in Ukraine’s Dniester River valley. Using advanced techniques, researchers were able to determine exactly how these fires were built and used some 23,000 years ago, during what scientists call the Last Glacial Maximum.

“We know that fire was widespread before and after this period, but there is little evidence from the height of the Ice Age,” says William Murphree, lead author of the study and geoarchaeologist at the University of Algarve.

What makes this discovery particularly significant is not just the presence of these hearths, but the scientific techniques employed to study them. The team used innovative geoarchaeological methods including micromorphology and colorimetric analysis to examine the microscopic layers of these ancient fireplaces. Their findings showed that Ice Age people built sophisticated fires capable of reaching temperatures above 600°C – hot enough to work with materials like bone and stone.

One of the most notable findings suggests these fires were predominantly fueled by spruce wood, not animal bones as sometimes assumed for resource-scarce environments. Charcoal analysis identified wood as the primary material, challenging previous theories about fuel scarcity during this extreme climate period.

“Some of the animal bones found at the site were burnt in a fire with a temperature of over 650 degrees Celsius. We are currently investigating whether they were used as fuel or just accidentally burned,” explains Marjolein D. Bosch, one of the authors and a zooarchaeologist at the University of Vienna, the Austrian Academy of Sciences and the Natural History Museum Vienna.

All three fireplaces were simple, open structures without stone linings, yet the analysis showed these hunter-gatherers employed sophisticated fire management strategies. The hearths were likely constructed and used differently based on specific needs, demonstrating remarkable adaptability.

“People perfectly controlled the fire and knew how to use it in different ways, depending on the purpose of the fire. But our results also show that these hunter-gatherers used the same place at different times of the year during their annual migrations,” explains Nigst.

Despite this new evidence, the relative scarcity of hearths from this time period remains puzzling. Researchers suggest several explanations, including the destructive effects of freeze-thaw cycles on archaeological sites or the possibility that humans developed alternative survival strategies during extreme cold periods.

“Was most of the evidence destroyed by the ice-age-typical, alternating freezing and thawing of the soil?” asks Murphree. “Or did people not find enough fuel during the Last Glacial Maximum? Did they not use fire, but instead relied on other technological solutions?”

The research provides a rare glimpse into the survival strategies of our ancestors during one of Earth’s most challenging climate periods. As climate change continues to transform our world today, understanding how ancient humans adapted to extreme environmental conditions may offer valuable insights for our own future.