Alarm bells on climate change

Australia is already bearing the brunt of climate change, reports Jeni Port. In response, the Australian Wine Research Institute and other bodies have been developing new tools for wine producers.

Australia could lose some of its oldest vines if the Barossa Valley is badly impacted by climate change.
Australia could lose some of its oldest vines if the Barossa Valley is badly impacted by climate change.

To witness a vineyard in its death throes is to see Mother Nature in the cruelest pain. Australian winemaker, Graeme Leith, watched his Passing Clouds vineyard in Central Victoria slowly succumb over 10 years. It was gradual decline.

At first, he was harvesting around 45 tonnes of fruit each vintage, but towards the late Noughties the crops were falling below four tonnes.

Ten years of prolonged drought saw his dam dry up, the ground turn as hard as steel.

Vines planted 30 years before were dying, even the hardiest grapes like Shiraz. Leith and his son, Cameron, sold up and moved to the Macedon Ranges, a far higher, cooler wine region. They became Pinot Noir makers.

We are living in a new climate. Graeme Leith knows it first-hand.

New tools 

Now, Leith and others are receiving the benefit of research work being conducted by the Australian Wine Research Institute (AWRI). Putting the best possible interpretation on a situation that could be perceived as dire, the AWRI has been presenting a series of talks to winemakers entitled: Opportunities in a new climate. 

The Institute has on board Dr Tim Flannery, one of Australia’s best-known scientists and a climate change activist. He’s a man not into putting the best possible interpretation on something he sees, very much, as dire. “The atmosphere is warming and has been rising particularly strongly since 1960,” he told winemakers, by way of introduction, at a climate change seminar in Melbourne. Around 90% of excess heat generated goes into our oceans. Australian vineyards, many of which hug the nation’s shores, will be impacted dramatically as the Antarctic ice cap melts causing higher tides, storm surges and rising sea levels. “It is the sleeping giant that will have the single-biggest effect on our country,” warned Dr Flannery.

Maritime wine regions such as Margaret River in Western Australia, southern Victorian regions, notably the Mornington Peninsula and Tasmania will be among the worst affected. The warming atmosphere will also be responsible for what Dr Flannery calls The Angry Summer: record temperatures, intense heat waves and bushfires. “This is what will happen if we do nothing,” he said. “If we continue business as usual.”

The challenge is to do something.

Last year the Australian government created The Carbon Farming Initiative, a carbon offsets scheme aimed at reducing carbon pollution and increasing the amount of carbon stores in the landscape.

Participation in the scheme is voluntary. Agricultural producers, including viticulture, account for 21% of greenhouse gas emissions in Australia. Wine producers can earn carbon credits through projects that sequester carbon such as the planting of native trees to regenerate the land, minimise erosion and lower salinity levels.

Nitrous oxide is a greenhouse gas that is around 300 times more potent than carbon dioxide and is formed in soils by a biochemical reaction, usually from nitrogen-based fertilisers that have been applied in excess. Products that inhabit the reactions that form nitrous oxide have been developed and research is underway to see how effective they are. Producers can audit their vineyard’s fuel and electricity use by using the Australian Wine Carbon Calculator.

Importantly, for viticulturists dealing with a hotter climate, a new range of sunscreens for grapes has been tested on the Semillon grape in the Hunter Valley. The sunscreen, which has been found to reduce berry temperature and sunburn is applied just before a ‘heat event’ – defined as a series of days over 35°C or a single day over 40°C.

Meanwhile, inside the winery, energy audits conducted by the AWRI have shown that heating and refrigeration produce extremely high energy consumption. Reusing the water that has been heated for one process (e.g. bottling line sterilisation) as a preheating option for another (hot water boiler) could potentially save up to 30% of a winery’s water heating bill. Changing to a different heating technology (such as an electrical heater versus natural gas heater) or using flotation as a technique for solids removal in place of cold settling, is another. 

Winery waste is also under the spotlight. Methane produced by livestock – notably cattle, sheep, goats and buffalo –is responsible for 65% of Australia’s agricultural greenhouse gas emissions and approximately 10% of total emissions. Reduced emissions may be possible by supplementing livestock feed with tannins – in particular grape marc – to reduce the production of methane. A three-year AWRI project looking into tannin in grape marc is due to be completed this year.

Talking it through

Australia is committed to a 5% reduction in greenhouse gas levels by 2020, compared with 2000 levels.  Dr Flannery sees a “reputational risk” looming in export markets if producers, such as those in the winemaking sector, continue to do poorly in green credentials. “This is very much a live issue,” suggests Andreas Clark, chief executive Australian Grape and Wine Authority. “It’s something that we probably need a robust discussion on.”

Some might suggest the time for discussion has passed. 

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