Tuesday, May 31, 2005

Australian climate change pre-dates (and therefore was not caused by) human presence

This is interesting. My understanding was that the transition of much of Australia to desert occurred some time after the arrival of humans and that, therefore, there was at least the possibility that the change in climate was the result of human activity. Recent research suggests that this may not be the case:
'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.'
I'm not clear on how findings in one area can back this up (desertification of an area resulting from human activity can presumably occur without human artefacts appearing in every "10-metre site" of the affected area, indeed, even without humans ever having been present in the affected area at all), but it is an intriguing data point.

(via ABC)