Few Australians are as associated with the carbon-cutting movement as Tim Flannery. Head of the federal government’s new Climate Commission and a media stalwart, Flannery uses the popular media to engage the Australian public, making his ideas relatively accessible to the average person.

Australian Conservation Foundation CEO Don Henry told The Power Index: “He is able to explain the science beyond the scientific community.”

Flannery had the unenviable job of selling the idea of a carbon price to the Australian public in 2011 when he was hand-picked by the Gillard government to head up the Climate Commission, which is supposed to communicate the science on climate change. Peter Garrett wrote in Time:

“Throughout the many years I have known him, Flannery has been a climate change communicator without peer in Australia — and at a global level, he ranks alongside an elite few, such as Al Gore.”

Flannery is a scientist (actually a mammalogist), but it’s not purely as a scientist that he has made his mark — and cracked The Power Index’s top 10. His great strength is in communication. Despite entering the climate field relatively late, he has proved a stayer in the face of some searing criticism, some of it personal and aimed squarely at him.

He comes across as a down-to-earth bloke and sometimes emphasises optimism, sometimes doom and gloom. He can sum up at an issue in a pithy phrase, while other scientists take an hour and many bewildering graphs to do the same thing (by which time the media has tuned out). His books The Weather Makers and The Future Eaters hit the best-sellers list in the United States, Canada, Germany and Britain in their first year of publication.

“He writes beautifully and simply,” La Trobe politics professor Robert Manne told The Power Index. “His voice resonates. It’s obvious he is the only informed public intellectual as influential in Australia in this area. It’s important we have talented scientists but also be able to communicate. He is committed to the cause of alerting the public to the dangers of climate change.”

He was Australian of the Year in 2007 for his work on climate change, a commendation awarded to him by Prime Minister John Howard — a climate change sceptic. “I was more surprised than anyone when I became Australian of the Year, Flannery told Manne. “I really think John Howard had a blind spot on this issue.” In 2012 he became a fellow of the Australian Academy of Science for his public advocacy of science.

It’s fair to say that Flannery’s influence is at a peak under Labor and the Greens’ uneasy minority government; it’s unlikely he would wield as much influence under a Tony Abbott government. He emphasises the serious risks of global warming, calls for deep cuts to emissions and supports a carbon price. This doesn’t auger well for co-operation with the Coalition.

But Australia’s “Dr Livingstone”, as wildlife documentarian Sir David Attenborough has termed him, is not without his critics.

He controversially supported an Australian nuclear power industry to replace coal-fired power stations. “We would then have a power infrastructure like that of France, and in doing so we would have done something great for the world,” he told The Age in 2006. He has since repositioned himself in support of renewable energy over nuclear.

His easy charm and simple but authoritative language have endeared him to many who were wary of the climate change message. But his background as a mammalogist, not a climate scientist, has seen some in the scientific community (as well as in the climate sceptic blogosphere) take umbrage.

Sydney University palaeontologist Dr Stephen Wroe challenged Flannery’s credentials in The Sydney Morning Herald:

“Just because a guy is well known does not mean he knows what he is talking about. I’ve got a fairly cynical view of Tim. He’s an opportunist. He knows climate change is a buzzword, but a few months’ work does not make him an expert.”

Right-leaning think tank the Institute of Public Affairs has called him a “religious cult-leader or wacko preacher predicting Armageddon”, in relation to forecasts Flannery made in 2008 “that the water problem for Adelaide is so severe that it may run out of water by early 2009”.

Manne concedes Flannery has made some powerful enemies, such as renowned climate sceptic Andrew Bolt and The Australian newspaper, because “he is so influential and measured in what he says. He can answer his critics with reason. He’s not afraid of them.

“He is a scientist. He is not a climate scientist, but he can read the literature.”