How is climate change affecting Australia's bushfire activity?

Lives have been lost and homes destroyed on the east coast of Australia as unprecedented numbers of bushfires tax emergency services to their limit.

A fire danger rating sign set to catastrophic on the outskirts of Wandandian south of Nowra, Tuesday, Jan. 8, 2013. Source: AAP Image/Dean Lewins

A "catastrophic" fire danger is also forecast for Greater Sydney - the first time the area has experienced the highest-possible classification since national ratings were devised a decade ago.

Researchers say the fires are happening for a number of reasons and most of those can be linked to climate change.