What is your opinion on the impact of global warming on the 2013 October wildfires in Australia?
Global warming creates earlier Summer weather, which creates an earlier start to the Summer fire season. Fires inevitably start at any time of the year, but during the fire season, fires spread much more easily and quickly, and are harder to put out. With an earlier start to the fire season, there are more weeks in the year when houses and automobiles and businesses are at an almost unacceptable risk of being overcome by fire.
In general, global warming not only increases the fire season in Australia, but in other places in the world as well. One example in 2013 is the island of Sumatra. As people on the other side of the strait of Malaca in Singapore and even as far north as the city of Kuala Lumpur in Malaya can attest from the reduced visibility from the smoke, there was quite a fire season in Sumatra. Another 2013 example of the increased intensity of the fire season was the western USA. As the decades progress, there is strong suspicion that some of the old rainforest jungles of Brazil will dry up from global warming and then eventually catch fire and turn into desert. For an older 2004 scholarly work on the subject of Brazilian effects of global warming, I recommend as an Internet search string "Amazonian precipitation decrease and forest dieback under global climate warming", written by scientists Richard A. Betts and others. It can be said from that paper that the 2005 and 2010 Amazon droughts were no great surprise. I recommend http://www.metoffice.gov.uk/research/news/amazon-dieback, for the latest information as of 2013 regarding where wildfire is projected to be climatologically inevitable for remnants of tropical forests.