High-profile climate change campaigner Al Gore on Monday backed Australia's environmental policies and said this year's devastating brushfires were a savage reminder of the need to act.

The former US presidential candidate, in Melbourne to launch the Safe Climate Australia think-tank, said Prime Minister Kevin Rudd had shown the environment was a top priority.

"In my country we have a new president and in only 30 days after taking office (he) was able to pass in the US Congress 80 billion dollars for renewable energy and for green infrastructure," Gore said.

"Your new leadership 18 months on here in Australia has done something similar."

Gore had earlier praised Rudd for pushing ahead with emissions trading legislation before a UN climate change conference takes place in Copenhagen in December.

Rudd also won plaudits from environmentalists by signing Australia up to the Kyoto Protocol on global warming as one of his first acts as prime minister.

Gore said Australia's worst ever brushfires, which were fanned by record temperatures and left 173 people dead, offered evidence that the planet had a "fever."

"It's difficult to ignore the fact that cyclones are getting stronger, that the fires are getting bigger, that the sea level is rising, that the refugees are beginning to move from places they have long called home," Gore said.

"The odds have been shifted so heavily that fires that used to be manageable now threaten to spin out of control and wreak damages that are far beyond what was experienced in the past."