Ice Age struck indigenous Australians hard

By Wes Judd | September 27, 2013

Population numbers plummeted due to harsh conditions at the peak of the last Ice Age, says a new study.

A NEW STUDY HAS revealed how indigenous Australians coped with the last Ice Age, roughly 20,000 years ago.

Researchers say that when the climate cooled dramatically, Aboriginal groups sought refuge in well-watered areas, such as along rivers, and populations were condensed into small habitable areas.

Professor Sean Ulm, lead author of the research at James Cook University in Townsville, says the vast majority of Australia was simply uninhabitable at this time. “Forests disappeared, animals went extinct; major areas of Australia would have been deprived of surface water.”

How humans coped with the last Ice Age

To understand how Aboriginal people responded to the conditions, a team of experts from Australia, England, and Canada used the radiocarbon dates of thousands of archaeological sites to study the distribution of people across the landscape over time.

The findings, published recently in The Journal of Archaeological Science, suggest that about 21,000 years ago, almost all people in modern-day Australia migrated into smaller areas, abandoning as much as 80 per cent of the continent.

“In Lawn Hill Gorge in northwestern Queensland, at the coldest point of the last glacial period, all of the stone, raw materials and food remains are exclusively from the Gorge area,” says Sean. “This indicated very limited or no use of the surrounding broader landscape.” 

This massive consolidation had drastic effects on the population as well. “There was likely a birth rate decline of over 60 per cent,” says Alan Williams, a PhD student at the Australian Nation University who worked on the study. “It would have been very ugly.”

Can humans cope with climate change?

Sean says the next step would ideally be to study the resulting cultural shifts, however, this may prove to be difficult given that close to one third of what was Australia at the time of the Ice Age is now underwater. “By 10,000 years ago, sea levels were visibly rising, sometimes on a daily basis,” says Sean.

Extreme changes in the environment continued for thousands of years, and Aboriginal life readjusted in the process. Sean says this makes it unlikely that researchers will ever know the full societal ramifications of the Ice Age.

What the study does reveal, however, is that humans have withstood massive climate change on this continent in the past, and this might prove vital for preparing for future events.

“A lot of the current climate reports that we read about in Australia…their records only go back a couple of hundred years,” says Sean. “That’s a very short time span to base our model for future climate change on.”

Sean adds that, thanks to studies like this, archaeologists may soon have the potential to extend these data sets.

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