Flannery, a zoologist, biologist, explorer, conservationist and writer, began his scientific career documenting the long-term impact of human activity on the tropical rainforests of Papau New Guinea.
Australian scientist Tim Flannery grew used to receiving quizzical looks in the 1990s as he pounded the corridors of power in Canberra urging politicians to do something about climate change.
"You'd go and see a federal minister and they'd stare at you like you were a raving idiot," Flannery says of his early lobbying efforts.
"You could see them thinking 'what's this guy spouting on about?'.
"That only changed recently."
A shift in the Australian public's attitude towards climate change, brought about in no small part by Flannery himself, means politicans are now far less dismissive of the scientist-turned-environmental campaigner.
The extent to which the views that Flannery's critics once derided as fringe nonsense have become part of the mainstream was demonstrated last January, when the 51-year-old was named 2007 Australian of the Year.
"Tim helps us understand the predicament we face, carefully laying out the science and showing us the likely effects of human-induced climate change," his award citation said.
"But he also offers us hope of a solution to stop and ultimately reverse this trend."
Flannery returned to Parliament House, where his calls for environmental action once went unheeded, to received the award at a glitzy ceremony presided over by then-prime minister John Howard.
If the conservative leader hoped that Flannery's acceptance of an award traditionally viewed as apolitical might tone down his criticism of government policy, he was to be disappointed.
Flannery continued to launch ferocious attacks on Howard's refusal to sign the Kyoto Protocol on climate change and used his status as Australian of the Year to broadcast his opinions as widely as possible.
"John Howard handed me the award but it was the people of Australia who gave it to me," Flannery told AFP.
"They gave it to me for raising these issues and I owe it to them to continue doing that. It's perhaps given a bit more gravitas to the issue than it might have had otherwise."
Howard was ousted in elections on November 24 by Labor Party leader Kevin Rudd, who has pledged to ratify the Kyoto Protocol.
Flannery, a zoologist, biologist, explorer, conservationist and writer, began his scientific career documenting the long-term impact of human activity on the tropical rainforests of Papau New Guinea.
He discovered 29 new species of kangaroo in the remote New Guinea highlands, surviving encounters with giant spiders, having arrows pointed at him by hostile tribesmen and contracting typhus and malaria.
Renowned British naturalist Sir David Attenborough described Flannery as an explorer in the league of historical figures such as David Livingstone.
He rose to public prominence in Australia following the 1994 publication of the ecological history "The Future Eaters," an examination of how mankind has altered the environment of Australasia.
Last year he released "The Weather Makers," which explains how the build up of greenhouse gases released by the burning of fossil fuels has damaged the atmosphere and is causing global warming.
This has resulted in the melting of the polar ice-caps, rising sea levels and the extinction of some species -- incontrovertible evidence that mankind's pollution is heating up the Earth, he said.
The book made best-seller lists around the world as the climate change warnings Flannery had been issuing for well over a decade finally gained public acceptance.
Flannery says the turnaround in pubic opinion occurred over a short period last year and he remains uncertain about why the change occurred.
"My feeling is that the Iraq adventure was a factor," he said.
"People thought 'well if the intelligence services and the president (US President George W. Bush) could get it so wrong on weapons of mass destruction then maybe they're wrong on other things'.
"It opened the way for them to challenge what they were being told about climate change, that it wasn't a problem."
Flannery this year took up a climate change research position at Sydney's Macquarie University and he is also chairman of the Copenhagen Climate Council.
In the latter role, he will be part of the Danish government delegation at the UN Framework Convention on Climate Change (UNFCCC) meeting in Bali from December 3, which will look at ways to negotiate pollution cuts after 2012 when the Kyoto Protocol pledges run out.