Climate Change Threatens Australia's Koala - Report AUSTRALIA: April 7, 2008 SYDNEY - Australia's unique tree-dwelling koalas may become a victim of climate change, new research reported on Saturday shows. Australian scientists say that eucalyptus leaves, the staple diet of koalas and other animals, could become inedible because of climate change. "What we're seeing, essentially, is that the staple diet of these animals is being turned to leather," Australian National University science professor Bill Foley was quoted as saying in the Weekend Australian.