He has been involved at the highest levels of business, diplomacy and public policy. But Professor Ross Garnaut looks very much the academic when he arrives for lunch carrying a book on Chinese security diplomacy in one hand and an umbrella in the other.
Garnaut's choice of eatery is an Italian restaurant in Melbourne's leafy North Carlton, not far from the University of Melbourne where he's based. In keeping with his views on climate change, he turns up in a hybrid Toyota Prius.
Garnaut's role as the government's climate change adviser has made him a national figure.
Such is his profile that he's even been impersonated on Twitter - surely a rare experience among academic economists.
"A 'Ross Garnaut' appeared on Twitter with my photo and my CV," Garnaut says with a worried look. "It would twitter quite a lot of things out of work that I had really done and then twitter things that I hadn't done. It was deliberate misinformation."
However, climate change is only a small part of the Garnaut story.
Over a hearty minestrone soup entree, we discuss the sweep of nation-changing reforms he's been associated with over the past three decades - the opening up of the economy, Australia's engagement with Asia and, most recently, the response to global warming.
Early in his career Garnaut concluded that the developing countries of Asia presented a huge opportunity to Australia, and vice- versa. But an open economy was needed to make the most of it.
"Our high tariff barriers effectively cut off trade with low-income counties of Asia … it was deeply inappropriate for Australia," he says.
The day Bob Hawke formed government, in March 1983, Garnaut was invited to Parliament House and offered a job as the prime minister's senior economic adviser. By December, the dollar had been floated, setting Australia on a brave new economic path - and Garnaut had his first serious taste of the reach and determination of vested interests.
Despite the polemic of the carbon tax debate - the carbon pollution reduction laws go to the Senate next week after their tense passage through the lower house earlier this month - Garnaut says his work on trade liberalisation in the 1980s was more unpopular with business and the wider community.
But genuine reform is becoming harder to achieve, he says, because big vested interests are more adept at swaying the political process.
Our main courses arrive - spinach and ricotta ravioli in mushroom sauce - and a waiter pours more sparkling mineral water as Garnaut reflects on how the digital age has raised the stakes in public debate.
"Their channels for influencing policies are more numerous, in some cases more subtle but in some cases cruder too," says Garnaut.
He recalls the pressure he and his staff came under during the climate change review. Whenever a scientist or an economist opened his or her mouth, they'd be bombarded by "tens of thousands" of emails. Other stakeholders, including MPs and Garnaut himself, were copied in.
"Some were abusive, some were life-threatening, of a crudity that's hard to imagine," he says. "I know lots of people involved in that debate who decided personally it wasn't worthwhile.
''So the threats were successful: they knocked some people out of the public policy debate."
Security precautions were required for his office and staff although Garnaut won't go into details. The deterioration in Australian political culture threatens to take a heavy toll.
"The media politics and the corporate politics that emerged around the climate change debate, like nuclear weapons, having been invented, will now be with us forever," Garnaut says. ''This will hamper Australia as economic challenges inevitably come our way.
"There'll be tough times ahead," Garnaut says.
"And the political culture that has emerged has put any Australian government, Labor or conservative, in a very difficult position to face up to the reforms and adjustments that are going to be necessary."
Garnaut could easily have ended up studying physics rather than economics. He excelled in science and mathematics at Perth Modern School, where he was school captain in 1963. As a teenager, he was the West Australian representative at a summer school for top science students held at the Sydney University.
"When I decided not to do physics as a 17-year-old kid, I did have some regrets," he says. "I remember thinking I won't be there when they work out what it's all about."
In the end economics won out because of his unusual interest in development in Asia and Australia's place in the world. "Even at high school, I was quite interested in those issues and, as a part-time thing after school, I took myself along to some Malay lessons," he says.
He did an undergraduate degree in economics at Canberra's Australian National University, followed by a PhD that investigated Australian trade with Asia. At the ANU, Garnaut met Jayne, his wife of 40 years, who also grew up in Western Australia.
Soon after finishing his doctorate, Garnaut joined Papua New Guinea's Department of Finance during the country's transition to independence and did pioneering work on a resources rent tax that was later adopted in several resource-rich nations, including in Australia as the petroleum rent tax.
Garnaut says the time in PNG as a young man was ''formative'' and he has been involved in various business and advisory roles there ever since.
He counts two former PNG prime ministers, Rabbie Namaliu and Mekere Morauta, among his "closest friends in the world". For 20 years, Garnaut has chaired a string of big public companies including Bankwest and Lihir Gold, which he led for more than a decade before it was sold to Newcrest Mining for nearly $10 billion last year.
He's held academic roles and written or co-written more than 40 books. "I think I would have found a life in which I was a conventional public servant, or simply a business leader, uninteresting and unrewarding compared with the life that I have led," he says. "I accumulate interests rather than drop them off."
As cappuccinos turn up at our table, Garnaut is keen to talk about what's next. His six grandchildren are a special focus.
"I'm delighted that my grandkids enjoy an afternoon at the MCG with granddad, summer and winter," he says. Garnaut is an avid follower of cricket and Australian Rules football, which he played competitively until his mid-20s. After making the East Perth District under-18 team, he played in the ACT league between 1964 and 1971. He backs his hometown team, West Coast Eagles.
There will also be more space for activities in PNG. Garnaut is chairman of the charitable trust that is entrusted to run the giant Ok Tedi mine "responsibly and profitably" and to invest the large dividend flow in sustainable development. This project is showing signs of "being transformational for Papua New Guinea development", he says.
Garnaut is also working on a "couple of books" postponed by his work on climate change - one on China's impact on global resources economy and another analysing China's economic reforms.
He has taken a keen interest in China since it began to open its economy in the late 1970s.
Garnaut, along with other academics from the ANU, were privy to rare briefings on the reforms by scholars sent by the Chinese government to the university soon after Beijing adopted its open policy.
"My views on China ever since then have been pretty steady. Once you knew what was happening in China - and we had an inside running on it - it was clear it was going to be pretty important."
Garnaut was appointed ambassador to China in 1985 and, on his return, he wrote the influential report Australia and the Northeast Asian Ascendancy, which shaped a fresh wave of economic reform announced by Hawke in 1991.
His two sons, John and Anthony, have inherited their father's interest in Asia and are both fluent Mandarin speakers. Several grandchildren are also proficient in Mandarin.
Not surprisingly, Garnaut also has plenty of invitations to speak about climate change.
His voluminous climate change review, published in 2008 and updated this year, has been praised internationally, particularly its analysis of the carbon abatement challenge posed by giant developing economies such as China and India.
The first instalment has been translated into Mandarin and copies sit on the desks of climate change officials in Beijing.
Despite the flack, Garnaut has no regrets about the role he has played in Australia's climate change debate.
"It has been bruising but I was given a job to do and I have just done it," he says.
"It was an important thing that I was asked to do and I tackled it like I have tackled everything in my life, with every bit of energy and intellect I have,'' Garnaut says.
''And I think I've done a good job."
Garnaut is more convinced than ever about the need for a comprehensive response to global warming.
"If we don't do something about it pretty soon, then we will have created pretty unmanageable challenges for our grandkids," he says.