Monday, January 11, 2010

Climate change article from the Age Newspaper.

Grape growers first to harvest a bunch of changes

JENI PORT - January 10, 2010

''SNOW'' Barlow's 2010 vintage is still an idea, the wine grapes formed but not ready to turn in colour or give up fleshy juice.

Two months after flowering and still in a dreamy pre-pubescence, they're about to get a nasty awakening, a major test of stamina, with temperatures destined to hit about 40 degrees today and tomorrow in Central Victoria.

Professor Barlow's Baddaginnie Run Wines and Seven Sisters Vineyard, 24 hectares of vines set against a backdrop of granitic outcrops that make up the Strathbogie Ranges north of Melbourne, are already feeling the effects of an unusual burst of hot weather that occurred in early November.

The dams are evaporating fast, and water is rationed to sustain some grapes through to harvest. Others will have to fend for themselves.

Recurring extreme weather, the face of climate change, is altering the nature of Victoria's - and Australia's - wine-grape harvest.

The harvest is coming earlier; for many regions, it's now in the middle of the hottest month of the year, February.

For the past four years, it has also come with a rush, often catching winemakers off guard and reducing the picking period to mere weeks instead of a few months. Any distinction between early-ripening grape varieties and late-ripening varieties at times seems barely to exist.

Professor Barlow and his partner, former Greening Australia chief executive officer Winsome McCaughey, have catalogued the changes in their vintage conditions since 1995, the year they planted shiraz, cabernet, merlot and verdelho.

That was also the year in which the region recorded its last ''average'' rainfall of 69 centimetres.

But with his daytime work hat on, Barlow - professor of horticulture and viticulture at the University of Melbourne - has also been cataloguing vintage climate data in wine regions across the country.

He has studied climate change since 1982 and oversaw the first major research work into its effects on Australian viticulture in 2006.

But the initial results of this latest study, yet to be completed, have already shocked him. At the start of 2009, his research team set out to find out just how far forward vintage had come in winemaking regions.

In one instance, the harvest of pinot noir at Main Ridge on the Mornington Peninsula had come forward 40 days in 40 years. For chardonnay grown on the same vineyard, picking dates were 32 days earlier than they used to be.

At Tahbilk, one of Victoria's oldest vineyards with vintage climate data going back to 1932, Professor Barlow's team found picking days had fast-tracked over the decades by 20 days. ''Unbelievable,'' he says.

Early data appears to be outstripping 2006 computer modelling, which predicted that harvest in areas such as the Riverina would be six to 12 days earlier than now by 2030 and between seven to 14 days earlier by 2050. Increased carbon dioxide in the atmosphere appears to be an important factor.

''It does help plants photosynthesise quicker,'' says Professor Barlow, ''and we are just wondering if you have the same amount of fruit [on a grapevine], the same amount of leaves and those leaves work harder you might get there [to harvest] quicker.''

Professor Barlow believes Australian winemakers are at the forefront of climate change detection - ''the canary in the coalmine'' as he puts it - because most growers religiously catalogue details of their year: temperatures, picking dates, sugar and acid readings, soil moisture tests.

He notes that he rarely meets a climate change sceptic in the wine industry.

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