Australian megafauna demise

At www.abc.net.au/science/articles/2010/11/30/3080101.htm there is another story blaming humans for the demise of megafauna in Australia around 40,000 years ago. The paper was published in PNAS but was not entirely convinced by the human hunting argument and for once contained a lot of evidence indicating environmental changes occurred at this time that were pretty wide ranging. There was also evidence of huge landscape fires so this is perhaps a paper to be read to glean the small detail.