Q. What are the long- and short-term effects of climate change on wine-producing countries?

A. While Australian summers are unquestionably warmer and winters drier than 20 to 30 years ago, there are still those in the industry, politics and media who deny the existence of climate change.

Their argument is that the current series of hot, dry seasons is a statistically acceptable incidence over a long period of time.

In my unqualified opinion, global warming has contributed to Australia's current heat and drought crises.

The cumulative effect of several seasons of this (with some amelioration in 2002 and 2004) is that deep soil moisture has become non-existent in most places and that vineyards have been subjected to an accumulation of stress, making them ever more vulnerable.

A regular viewer of international news TV channels wouldn't be surprised to see rivers flowing where roads should be, fires burning out of control and winds dumping boats on houses.

The world has become more accustomed to climatic extremes, as once-in-a-century instances of frightening intensity happen ever more frequently.

Europe, too, is clearly experiencing warmer summers. Now, you need a really good reason to buy many European whites from 2003 - the year was just too warm for most.

But there are winners too. Cooler, more marginal wine regions are likely to benefit from global warming.

Indeed, the cooler regions in southern mainland Australia and Tasmania have never had it so good.

England is benefitting from it too. A Champagne house recently bought land in southern England, on soils virtually identical to Champagne but in a significantly cooler climate.

So in the long term, the world of wine as we know it will change. I can't see how it won't.

In the short term, with the present lack of knowledge on such matters as 'how hot', 'how often?' and 'for how long?', the wine world simply has to protect itself and act with heightened intelligence and sensitivity towards the environment. As, indeed, do we all.