'Catastrophic' conditions as bushfires rage in Australia

A scorching heatwave intensified bushfires ravaging parts of Australia on Dec. 21, and out-of-control blazes surrounding Sydney worsened under "catastrophic" conditions.    

Australia's eastern coast has been hit by a record-breaking heatwave, which has moved in from the west of the country, fanning hundreds of fires in its path.    

Sydney was shrouded in toxic smoke as blazes flared to its north, south and west, some just 130 kilometres (80 miles) from Australia's largest city.    

"Today has been an awful day," New South Wales sate fire commissioner Shane Fitzsimmons said on Dec. 21 afternoon.    

Temperatures were expected to peak at 47 degrees Celsius (116 Fahrenheit) in parts of the state -- the country's most populous -- including in parts of west Sydney.    

Australia endures bushfires every year but the early and intense start to this season, along with the record temperatures, has fuelled concerns about global warming.    

The fires have torched at least three million hectares (7.4 million acres) of land -- an area equivalent to the size of Belgium -- with at least 10 people killed and more than 800 homes destroyed.    

Two massive blazes south of Sydney generated their own thunderstorms, fire authorities said, with a "mega fire" burning to the north also threatening the dangerous phenomena.  

 A fire-generated thunderstorm can occur when a smoke plume is cooled as it meets pressure in the atmosphere, creating a cloud capable of producing its own lightning and powerful winds.     

Some 3,000 firefighters across the state were bracing for a wind change in the afternoon, expected to bring "dangerous and difficult, volatile conditions", Fitzsimmons added.    

"We will not get on top of...