30,000 – 15,000 years ago
Starting from around 30,000 years ago the climate gradually became colder and colder, windier and drier. Between 24,000 and 18,000 years ago it became the coldest and driest it had ever been since people arrived in Sahul. Scientists call this period the ‘Last Glacial Maximum’. Back then temperatures would have been between 9 and 6 degrees Celsius lower than today.
Glaciers developed in the Snowy Mountains (NSW) and in the Tasmanian Highlands.
Dry forests and wood-shrublands survived through this period but many areas of southern Australia became barren.
Dry conditions lasted longer in some areas. Northern Cape York stayed rather dry until 10,500 years ago and the rainforest probably shrank to small patches during this time. The dominant vegetation for much of this area was sclerophyll woodland. Lake Carpentaria and the Atherton Tablelands were covered in open eucalypt woodland.
During this time there was a stark decrease in available freshwater and in plant and animal foods that people could rely on and so, many areas were abandoned, as they became uninhabitable. People gathered around a few ‘refuge’ areas where permanent freshwater sources were available and where it was still possible to find plant and animal foods. People would have been less mobile during this time.
Some scientists think that in these very difficult conditions the number of people living in the country diminished by more than half (population fell by an estimated 60%).