Chateau Shanahan holds in trust eight crystal wine decanters for the son of the late Professor Tony Barnett, Chair of Zoology at the Australian National University from 1971 to 2003. Barnett and his wife Kate collected the decanters over many years.

Barnett developed an appreciation of wine as a student at Oxford University in the 1930s. He often spoke of a friendship with distinguished British wine writer, Edmund Penning-Rowsell, author of the magnificent “The Wines of Bordeaux”.

Each decanter surely represents a chapter in Barnett’s long life. We even have a hunch about which one hosted his much-talked-about, last bottle of Chateau Cheval Blanc 1947, one of the great Bordeaux’s of the 20th century.

This fragile old link to Barnett’s university life in the UK provides a symbolic connection with University House’s seventh wine symposium held on 20 and 21 May.

Just as Oxford sparked Barnett’s interest in wine, the House’s first symposium, in the 1950s, owed much to the long, traditional link between English universities and fine wine. But the interest now has a global focus and a strong Australian accent – as I witnessed at the memorable 1979 symposium and at last month’s event.

The 1979 event featured luminaries and winemaking stars of the day, including Professor Helmut Becker of Geisenheim, Germany, and Max Schubert, Wolf Blass and Cyril Henschke from Australia.

Just three years in the industry, I recall meeting for the first time many leading industry figures, including James Halliday. A lawyer, vigneron, author and columnist, Halliday had already become an influential opinion maker. He returned this year as the symposium’s after dinner speaker. We’ll return to his topic later.

A generation later, University House’s 2011 symposium recognised the Canberra district’s 40th anniversary. Brian and Janet Johnston launched the second edition of “Wines of the Canberra District: Coming of Age”, delegates tasted Canberra wines at the end of day one, toured our vineyards on day two, the dinner featured local wines, selected by Nick Bulleid and Nick Stock, and speakers wove Canberra into their presentations.

Brian Croser (Tapanappa Wines) and Dan Buckle (Mount Langi Ghiran) talked, respectively, on Canberra’s two proven specialties, riesling (“the noblest white”) and shiraz (“past present and future”).

Writer Nick Stock put alternative varieties in perspective. And Libby Tassie followed up with more technical aspects of growing these varieties.

However, climate change will be long remembered as the first, last and lingering topic of the symposium – as much for the topic as for debate about the debate.

Professor Andrew Pitman, head of climate science at the University of New South Wales, presented the first paper “Climate change and its local effects in Australia”. And to the surprise of those expecting a tame after dinner talk on Canberra district wines, James Halliday concluded the symposium by questioning the extent of human-induced climate change.

Halliday declared that he was making a sales pitch for a new book, “Wine, Terroir and Climate Change”, by Dr John Gladstones. He quoted his own words from the book’s cover, “For anyone interested in the future interaction between climate, climate change and viticulture, this book simply has to be read. Dr John Gladstones’s painstaking research is the foundation for his equally carefully constructed conclusions that robustly challenge mainstream opinions”.

The packed hall fell silent. After charting his own scepticism about climate change, Halliday said he’d been mesmerised by Andrew Pitman’s view the day before that sceptics had no place on the face of the earth. Halliday then summarised Gladstones’ conclusions and said, “His views of climate change will be vigorously debated, but not by me”.

I listened in fascination as I’d begun reading Gladstones’ book the day before the symposium – turning direct to the climate change chapters towards the end.

The day before, like Halliday and probably others, I’d been irritated by Andrew Pitman’s brook-no-dissent invective. Before presenting the science, Pitman told us, repeatedly, that we simply had to believe the experts. I’m not a scientist, so I expect scientists to guide me through the complexity of climate change — especially the enormous areas of uncertainty. Instead, Pitman muddied his science by insisting on us having faith in the experts.

Much of the uncertainty relates to calculating the extent and timing of temperature rises and separating anthropogenic from natural changes.

In a Canberra Times article prompted by Halliday’s talk, astronomer Brian Schmidt wrote, “I believe that science makes progress by continually challenging itself, looking for failed predictions, inconsistencies, or alternative ways of approach a problem. Few scientists become famous by towing the party line, it is by finding fault with the status quo, and improving it that scientists make their mark. So it is no wonder that there is not unanimity in any area of science – climate change is no different. The vast majority of scientists who study climate change believe anthropogenic CO2 is leading to a warming of the Earth, but there are still some who challenge this assertion. Long may this continue – but only if these challenges are based on a fundamental understanding of the science at hand, and not some anecdotal or highly limited form of phenomenological evidence”.

Now, Halliday based much of his symposium speech on Gladstones’ book – not on anecdotal or phenomenological evidence.

After a detailed discussion of the natural and anthropogenic influences on climate change, Dr Gladstone concludes, “that warming by anthropogenic greenhouse gases has been much over-estimated. The widely publicised claims of the Intergovernmental Panel on Climate Change (IPCC) and other greenhouse proponents have depended too much on computer models unable to encompass the complexity of real climates; on uncertain data, dubious assumptions and in some key cases biased statistical procedures; and particularly in ignoring the historical record of past climate warmth. Much of the thermometer record of warming over the last 100–150 years, which the IPCC ascribes more or less exclusively to greenhouse gases, has more likely other causes”.

He further concludes that “greenhouse gases can have caused no more than 0.2ºC of warming [over the twentieth century], which equates to only 0.4–0.5ºC temperature rise for each successive doubling of atmospheric CO2 or its combined greenhouse equivalent”.

As a somewhat confused non-scientist seeking guidance on climate change, I hope that scientists might therefore review and comment on Dr Gladstone’s research and conclusions. He might be right. But he could be wrong, too. I simply don’t know.

Copyright © Chris Shanahan 2011