HUMAN IMPACT ON ANCIENT AUSTRALIA'S CLIMATE

A group of scientists has concluded that humans did not eat Australia's megafauna into extinction:

Mr Price says the research rules out humans as the culprit for the local extinction of the megafauna.

"We've done a little bit of radiocarbon dating on the deposits itself and we know that the age of the deposits pre-dates the first humans on the Darling Downs by about 30- to 35,000 years," he said.

"We know that there's no human or cultural artefacts in the deposits as well and we know that all the cut marks on the bone themselves are related to... some of the other species that lived on the Darling Downs, such as marsupial lions."

That leaves one main culprit.

"That culprit is climate," Mr Price said. "It does appear that climate change was the major factor in driving the megafauna extinct."

This is in keeping with the notion that prior to white settlement humans in Australia lived in harmony with nature.

It is possible, however, that Australia's ancient climate was changed by human activity:

Settlers who came to Australia 50,000 years ago and set fires that burned off natural flora and fauna may have triggered a cataclysmic weather change that turned the continent's interior into the dry desert it is today, United States and Australian researchers say.

Their study, reported in the latest issue of the journal, Geology, supports arguments that early settlers literally changed the landscape of the continent with fire.

As this is a politically incorrect idea, it will be a hard sell.