CANBERRA - As firefighters continued to battle huge fronts in Western Australia and Tasmania yesterday, confirmation came that worse lies ahead as the nation is heated further by global warming.

The Bureau of Meteorology said Australia had been getting hotter every decade for the past 70 years and the trend was expected to continue.

Its latest climate statement said the past 10 years were the hottest decade since records began.

Last year - Australia's second-hottest - produced record-breaking heatwaves that saw temperatures soar to 46.4C in Melbourne and forced Adelaide to endure eight consecutive days above 35C.

The Bureau of Meteorology's annual climate statement said the mean temperature for the past 10 years had climbed 0.48C above the 1961-1990 average, climbing further last year to 0.9C above the average.

Predicting that this year could be even hotter, the bureau said the trend was further evidence of climate change.

"Based on the analysis of daily maximum and minimum temperature data ... there are clear upward trends in the number of hot events and downward trends in the number of cold events [since 1960], consistent with the background of global warming," it said.

Each decade since the 1940s had been warmer than the preceding 10 years, in contrast to a lack of any specific trend in previous decades.

"This suggests an apparent shift in Australia's climate from one characterised by natural variability to one increasingly characterised by a trend to warmer temperatures."

The Government leapt on the bureau's statement to support its climate change policies and the emissions trading scheme blocked in the Senate after Opposition Leader Malcolm Turnbull was ousted by Tony Abbott.

Environment Minister Peter Garrett said the statement showed Abbott's claim that global warming had stopped was completely at odds with the rigorous scientific findings of the bureau's independent experts.

"Australia is one of the hottest and driest inhabited places on Earth, and our environment and economy will be one of the hardest and fastest hit by climate change," Garrett said.

"Worryingly, projections suggest we can expect worse to come, including more frequent heatwaves and longer and more frequent droughts."

Meanwhile, Western Australia remains in a state of high alert, with another hot, windy day predicted and firemen still working to control outbreaks that came close to burning into coastal towns.

On the outskirts of Perth, residents have moved back to their homes after a fire - allegedly started by a teenage arsonist - threatened homes in the eastern suburbs of Whiteman Park, Beechboro and Caversham.

A 17-year-old youth has been charged with lighting a fire likely to cause damage and injury.

And while an expected cool change tomorrow may bring some relief, Western Australia has yet to face its summer bushfire peak amid fears across Australia that this may become the most dangerous season in a century.

Hundreds of fires have already incinerated thousands of hectares in the eastern states, and yesterday firefighters worked through their fourth day against flames that have burned through the north of Tasmania, endangering homes in the Beaconsfield and York Town areas.

Even before the bushfire season moved into its January-February peak, 12 homes were lost and 80 properties damaged at Port Lincoln in South Australia, and 37 houses were lost around Toodyay, 80km northeast of Perth.

Forecasters are predicting more severe heat as the present El Nino threatens to push this year towards a new record.

The tropical low that had been expected to develop into a cyclone yesterday eased, lowering the risk of destructive winds but still forecast to deluge much of the Northern Territory.