Wednesday, April 23, 2014

Climate change implications for Australian viticulture

I was interested to hear the chief IPCC scientist with responsibility for Australia and New Zealand holding forth on the implications for Australian viticulture, and, in particular, prophesising death, doom and destruction for regions already warm.

Well, the cool regions of Southern Victoria and the Adelaide Hills have just finished a vintage with yields somewhere between one-third and one-half of a normal harvest. And, no, it was not the heat in March, but the protracted cool and wet weather last spring which catastrophically interrupted flowering, leading to tiny bunches with small full-sized berries. When you have to choose between weather which is too warm, and weather that is too cold, vines and humans react in similar fashion.  More people are killed by cold weather than hot, and the same is true of grape vines.

Turning to warm regions, it is passing strange that the Hunter Valley had a truly excellent vintage in 2011, but one that pales into insignificance compared to that of this year. Most of the winemakers I have spoken to agree it (2014) is the best since 1965. Mind you, this is rear vision stuff, because few, if any, were actually making wine in 1965. This is where wine is such a wonderful thing, because anyone with Lindemans Bin 3100 or 3110 in their cellar know they have wines which are still in the prime of their life, and, if recorked, will cruise through to 2065. Any other shirazs from 1965 are also worth their weight in gold.

One obvious answer to the IPCC riddle is that global warming has inconveniently ceased since 1997, notwithstanding significant ongoing increases in CO2 emissions.

Another take on the subject came when I visited the Gold and the Incas – Lost Worlds of Peru exhibition at the National Gallery of Australia. The beautifully illustrated and detailed book available at the exhibition is a treasure in itself, however much it makes you realise the unbelievable extent of artworks of all kind that were destroyed over the following centuries. The Moche civilisation in the north of Peru, and which prospered between 100AD and 800AD was ended not by invasion, but an altogether different cause, which might give the IPCC pause for thought. Quoting directly from the book ‘The downfall of the Moche is linked to the disastrous consequences of a severe El Nino in the 6th century, which caused 30 years of flooding, then 30 years of drought. Such disruption undermined belief in the supernatural power of the rulers.’ I wonder whether these supernatural powers of the IPCC might also be called into question.

Finally, those watching ABC television recently, will have seen the patterns of the last ice age a mere 8000 years ago. The northern half of present day Australia was covered under a deep mantle of ice. This ice age ended quite abruptly, with rapid warming chronicled, but not understood.

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