General News

Ice Age research reveals climate change secrets

Climate change research has uncovered major – and surprising – changes to the Australian landscape linked to much colder temperatures during the last ice age.

A recent study shows that Lake Mungo, in western NSW, was up to 10 metres deep about 20,000 to 30,000 years ago, despite a period of low rainfall.

Lead researcher Professor Tim Barrows has linked this finding with new research on Black Mountain, Canberra, which shows temperatures were more than 8 degrees colder during the ice age than they are today – 2 degrees colder than observed elsewhere.

“The studies reveal that despite the absence of great ice sheets, the landscape was very different during the last ice age,” said Professor Barrows, of the University of Wollongong (UOW) and also of the University of Portsmouth, UK.

“Most of the hills and mountainous areas of southeast Australia were treeless with sparse vegetation.

“This not only led to major landscape changes but also would have led to major shifts in the distribution of plants and animals and the habitable zone for the first people in the region.”

Evidence of frost shattering of rocks shows that temperatures similar to what occur today around Mount Kosciuszko would have been experienced in the Canberra region.

“The climate change seen at Black Mountain suggests why Lake Mungo contained more water,” he said.

“Snow falls lasted longer with increased spring run-off and lower temperatures led to lower evaporation.

“Colder temperatures mean fewer plants which means less erosion protection on slopes and more run-off.

“These factors conspire to get more water out into the rivers and lakes.”

He said the research provided important clues about how the environment evolves with climate change.

“The research establishes a baseline for sensitivity of the region to climate change and its natural variability,” he said.

“The temperature rise after the ice age, the greatest global warming in recent geological history, completely changed the face of the Earth.”