If we want to think about how to deal with the effects of climate change, archaeologists suggest Aboriginal Australians are a good place to start.

Aboriginal civilization met the challenges of extreme climate change during the Last Glacial Maximum, which peaked around 20,000 years ago and again later during the Antarctic Cold Reversal. The researchers used archaeological radiocarbon ages and geospatial techniques to analyze archaeological radiocarbon dates from across Australia and found that during times of high climatic stress, human populations contracted into localized environmental 'refuges', in well-watered ranges and along major riverine systems, where water and food supplies were reliable. 

Annual temperatures plummeted by as much as 10 degrees below present-day levels, with massive reductions in rainfall. Glaciers appeared in the Snowy Mountains and Tasmania.

"The period scientists call the Last Glacial Maximum, or LGM for short, is the most significant climatic event ever faced by humans on this continent," co-author Associate Professor Sean Ulm from James Cook University in Cairns said in a statement. "The magnitude of change was phenomenal. Lakes dried up, forests disappeared, deserts expanded, animals went extinct and vast swathes of the Australian land mass would have been simply uninhabitable.

"This was a time of massive change. Sea levels fell more than 120 meters during the LGM, exposing much of the continental shelf and connecting mainland Australia to Papua New Guinea and Tasmania." 

Co-leader of the study, Alan Williams from the Fenner School of Environment and Society at The Australian National University, said surviving the last ice age required Aboriginal communities to adapt to massive change. "As much as 80 per cent of Australia was temporarily abandoned by Aboriginal people at the height of the LGM, when conditions were at their worst. 

"Along Australia's east coast, people contracted to refuge areas with good water supplies – most likely the result of increased summer snow melt coming off mountain ranges like the Victorian Alps, or glacier-fed river systems such as those of the central highlands of Tasmania."

Ulm said that while those better-watered areas would have provided more reliable resources, Aboriginal people needed to make significant changes to their way of life in order to survive. "The archaeological evidence reflects major changes in settlement and subsistence patterns at this time. Many previously occupied areas were abandoned.There were changes to hunting practices, the types of food people were eating, and the technologies they were using, to deal with new circumstances.

"We expect there would have been huge impacts on social relationships and religious beliefs as well, but these types of changes are much harder to detect in the archaeological record. One thing we can say for sure is that extreme climate change results in the fundamental social and economic reorganization of society.

"This was certainly true in the past and will be true in the future."

Citation: Alan N. Williams, Sean Ulm, Andrew R. Cook, Michelle C. Langley, Mark Collard, 'Human refugia in Australia during the Last Glacial Maximum and Terminal Pleistocene: a geospatial analysis of the 25–12 ka Australian archaeological record', Journal of Archaeological Science Volume 40, Issue 12, December 2013, Pages 4612–4625 DOI: 10.1016/j.jas.2013.06.015