Roughly 4000 years after the last glacial period, hunter-gatherers faced another bout of sudden climate change that forced them to rapidly adapt to a much colder world.
While not as frigid or long-lasting as the final stages of the last glacial period, which ended about 11,700 years ago, the 8.2 ka cooling event still caused temperatures to plummet by as much as 6°C (10.8°F) within decades. At the same time, a land mass the size of Scotland broke away from the Norwegian continental shelf, triggering the powerful Storegga tsunami, which delivered the final blow to Britain’s separation from Europe.
Through it all, people across the northern hemisphere survived, some by packing up and moving, others by sticking it out, says at the University of Oxford. “These people weren’t passive victims, they adapted quickly.”
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Scientists have already studied how the 8.2 ka event affected people across the northern hemisphere, but most of this research has been regional. To take a broader view, Schulting and his colleagues compared archaeological and environmental records between north-western Europe and southern Siberia.
The archaeological records included large hunter-gatherer cemeteries and nearly 300 radiocarbon-dated human and animal remains from the Baikal region in south-east Siberia alone. They combined this with high-resolution environmental records, such as pollen and charcoal preserved in lake sediments, which reveal past shifts in vegetation, climate and fire activity with decade-level precision.
The results show that people adapted to the 8.2 ka cold snap in markedly different ways. In Norway’s Oslo fjord, for example, the number of settlements increased. This suggests that coastal communities may have thrived by eating fish, seals and shellfish, which remained stable as the climate turned.
Likewise, at Lake Baikal, similar aquatic resources may have buffered local populations – so well, in fact, that archaeologists have found almost no trace of a human response to the 8.2ka event.
But around Lake Onega in north-west Russia, there was a surge in cemetery use that wasn’t linked to premature deaths or mass mortality, which suggests that local hunter-gatherers clustered here during the chill, probably drawn by reliable supplies of fish and elk. Meanwhile, on the west coast of Scotland, people appeared to step away from their coastal fishing lifestyle, possibly retreating inland to ride out the cold.
The 8.2 ka event offers an important “worst-case scenario” model for understanding abrupt climate shifts and demonstrating how global warming can change ocean currents and lead to major cold snaps, says at the University of Helsinki in Finland.
A collapse of the Gulf Stream today could lead to a similar outcome, he says. “In the same way as 8200 years ago, humans today will also need to find ways to adapt to the resulting crisis.”
at Ghent University in Belgium finds the team’s region-to-region comparisons “especially valuable”, both historically and today. “We know from modern climate change that environmental impacts vary dramatically from one region to another,” he says. “This study makes it clear the same was true in the past.”
The findings don’t just reveal how people responded to climate change historically, they also show how different their options were compared with ours, says Schulting. “People don’t really care if it’s 1 or 2 degrees warmer or colder – until it affects the rainfall patterns, the migrations of animals, the kinds of plants that are available,” he says. “If you’re a hunter-gatherer and your environment suddenly turns hostile, you could just walk away, but that’s much harder to do when you’ve got roads, cities and supply chains. That kind of mobility is a luxury we don’t have anymore.”
Quaternary Environments and Humans
