In focus: How the Australian wine industry is dealing with climate change

Climate change is having a major effect on Australia’s wineries, as temperatures rise and water becomes increasingly scarce. Phoebe French speaks to winemakers in the country about how they are adapting to increasingly erratic conditions.

Last summer was Australia’s hottest on record. It was also one of the 10 driest the country has experienced, with only parts of northern Queensland and northwest Victoria exposed to above-average rainfall.

The Australian Government Bureau of Meteorology revealed that 2018 was Australia’s third-warmest year on record, with the annual national mean temperature 1.14 °C above average. The potential for an El Niño warming weather pattern remains, with a 50% chance of it developing during the southern hemisphere’s autumn or winter this year – twice the normal likelihood.

With extreme temperature spikes and unsettled weather becoming more frequent, how is climate change affecting the nation’s AU$6 billion (£3.3bn) wine industry? And in a country covering 7.69 million square kilometres, with 65 registered wine regions and 140,000 hectares under vine, is it even possible to generalise?

“Contrary to what President Trump suggests, it’s not ‘just weather’, and we can’t bury our heads in the sand,” says Paul Braydon, buyer at UK wine supplier Kingsland Drinks, which works with wineries based in Victoria, South Australia and New South Wales .

He recounts how this year, while the vintage is not yet complete, there are early indications that “significant weather events” have led to a fall in production volumes and a rise in grape prices.

Lower volumes

Braydon adds: “Forecasts are for volumes to be 30-50% down this year from the premium regions including Barossa, McLaren Vale and Clare Valley, and 10-30% from the Riverland. Grape prices are up by around 25% for red varieties to around AU$600 per tonne and 9% for whites to AU$375 per tonne, compared with 2018. Water is now AU$570/ml for temporary water rights.”

According to a 2011 study, published in Global Change Biology, observing changes in grape maturity in Australia, Webb, Whetton and Barlow examined the records of 44 sites, finding that grapes ripened at a rate of 1.7 days earlier between 1993 and 2009.

A study in 2012 in Nature Climate Change published by Webb, Whetton, Bhend, Darbyshire, Briggs and Barlow found that warmer temperatures and lower soil-moisture levels contributed to this alteration.

It noted, in the period from 1985 to 2009, that grape maturation dates had advanced by eight days per decade in southern Australia. Nine out of 10 sites studied exhibited earlier ripening trends, with only vineyards in Margaret River in Western Australia showing later ripening when observed over the full period of 1977 to 2009.

Geoff Merrill, owner and winemaker of his eponymous wine label in McLaren Vale, agrees with the findings. “Over the past 20 years we have seen an average shift in harvest date by approximately two weeks earlier than the past,” he says.

He also notes that not only has the vintage been brought forward, but it has also been compressed. “The beginning of the vintage may be two weeks earlier, but the duration of the vintage is much shorter. We must crush more per week than ever before,” he adds.

Neil McGuigan, CEO of Australian Vintage, which owns McGuigan Wines, Tempus Two and Nepenthe, explains that needing to get grapes off the vines faster has resulted in significant investment in harvesting and winery equipment.

“To ensure grapes are being harvested at the optimum level of ripeness, winemakers are starting to use more processing equipment to increase the amount of grapes that can be picked per day,” he says. “As temperatures get warmer we have to invest in products to offset the seasonal variations. We are doing this by making sure we have the capacity to cope with a higher influx of grapes at one given time.”

The winery is not the only area where investment is being made. In the vineyard too, winemakers have adopted practices to cope with the heat. Growing a larger leaf canopy to generate shade and protect grapes from sunburn is becoming very important, says Merrill.

In research published in January 2019, Charles Sturt University postdoctoral researcher, Dr Joanna Gambetta, from the National Wine and Grape Industry Centre (NWGIC) said sunburn can affect up to 15% of wine grapes in Australia in any given season.

“The browning, cracking and berry shrivelling means that yields are reduced and the fruit can be downgraded, causing significant economic losses to growers and wineries,” she says.

“On a sensitive, fully mature Chardonnay grape, symptoms of sunburn can appear within five minutes once surface temperature on the berry reaches an ambient temperature of 40–43°C.”

Adam Levy, founder of International Beverages Competitions, notes the creative ways in which Australian winemakers are adapting to change to ensure grape- and wine quality are not affected. “Some are experimenting with new grapes that may be able to handle the climate disruption,” he says. “Others are looking for better ways to control the moisture of the soil to reduce sudden and extreme differences. Some are also looking at land at higher altitude to combat the rising heat, which leads winemakers to review their use of land.”

Techniques including mulching and low-growing cover crops to retain soil moisture, planting at higher altitudes, growing hot-climate and drought-tolerant varieties including Tempranillo, Assyrtiko and Nero d’Avola, and even putting special ‘sun cream’ on grapes, are all being implemented in Australia.

Warmer conditions

Louisa Rose, head winemaker of Yalumba in the Barossa Valley, explains: “Many of our traditional and existing varieties are particularly suited to warmer conditions – Grenache, Viognier, Shiraz and Mourvèdre in the Barossa are great examples of this. Other ‘newer’ varieties to Australia are also showing how well-suited to our climate they are. These include Tempranillo, Vermentino, Verdejo, Assyrtiko and Nero d’Avola.

“As viticulturists and winemakers we are very clever at understanding grape vines and using techniques such as the shading of grapes, different trellising, cover crops, use of native grasses, mulches on soils, irrigation and ‘sunscreens’ (kaolin clay mixed in water and sprayed on vines) to change the microclimate around the vines to mitigate against weather extremes.”

Assessing the impact of climate change on Australia’s wine itself is more challenging, given the different styles that are produced in the country. Originally known for its fortified wines, gutsy reds and heavily-oaked Chardonnays, Australia’s style has evolved to focus on lower alcohol and preserving freshness, even in the hottest of regions.

Paul Schaafsma, managing director of Benchmark Drinks, says: “The vintage in Barossa this year has been severely affected, and trying to make the styles of wine that they’ve been doing in Barossa is going to be difficult unless you’ve got your grapes off early.”

He noted that successive spells when the mercury rose to 30-35ºC during harvest may affect the resulting wines. “The baumé levels go up, the alcohol levels go up, and the winemaker’s work is going to be difficult,” he says.

Merrill, in McLaren Vale, believes there have been perceptible changes, although “each vintage is still very different from each other. We can only generalise. Overall, we’ve seen an increase in ripe fruit characters and an increase in colour but acidity has declined to a small degree over time.”

McGuigan, however, is adamant that while changes have been made in the winery to cope with a compressed vintage, “the extreme weather hasn’t changed our wines”.

Rose of Yalumba, likewise, shares his scepticism. “There is more to the character of grapes and wine than just the temperature that the grapes ripen at. This year in the Barossa, from one of our warmest vintages, we have some great wines that are very typical of what we expect from the region. Eden Valley Riesling is fragrant and delicate and has as high if not higher natural acidity than in some cooler years,” she says.

“This would suggest to me that there are other very strong influencers on terroir than just temperature. Long-term trends in wine style are hard to put down to any one factor as there are always multiple influences. I would argue that the evolution of style of wine because of changing tastes and fashion happens faster than an influence that we may see due to climate or the weather.”

Cooler regions, such as Margaret River in Western Australia, are exhibiting fewer signs of global warming.

Vanya Cullen, of Cullen Wines, says that this year, the harvest was a month later than in 2018 because of cool conditions.

“There was a study done by CSIRO [The Commonwealth Scientific and Industrial Research Organisation] from 1976 to 2010 that plots when the Cabernet Sauvignon harvest was at 12 baumé ripening,” she says. “It hasn’t changed statistically in Margaret River, but in all other wine growing areas in Australia the date has moved forwards, with the exception of McLaren Vale, although this could show the effect of ocean being close.”

The elephant in the room in all of this is water. One of the major issues threatening the Australian wine industry is the availability of water for irrigation.

In 2018, Australia experienced annual rainfall that was 12% below average, with much of New South Wales, Victoria, eastern South Australia and Queensland affected by drought. It’s no coincidence that water-conserving irrigation techniques, such as regulation-deficit irrigation and partial-rootzone drying were developed and tested in the country.

Water supply is strictly monitored in many parts of Australia, and the cost of obtaining it needs to be factored in to wine production.

Water licences

Schaafsma says there have been years in which only 15% of available water licences have been granted. “That really puts a huge impact on the grower in terms of cost and keeping their crop going,” he says. “The whole of the Riverland is irrigated by drip irrigation coming out the Murray River – the responsible management of water in Australia is critical. In terms of expansion of vineyards in certain areas, there has got to be appropriate management of the available water and therefore which vineyards it can support.”

Schemes such as using reclaimed water for irrigation are becoming increasingly widespread. McGuigan, however, is an advocate for more extreme change. “Water management is fundamental: we manage our vineyards incredibly efficiently, and the amount of water our vines use is less than other crops. Due to extreme temperatures, we may have to increase the amount of water we use to look after our vines and, as a result, the flow of water into the Murray Darling Basin is crucial.

“This can be achieved by more vigorous controls of irrigation out of the Murray Darling Basin, while, at the same time, looking at increasing the flow in. This would be a controversial step, but we have a lot of water at the top of Australia and we need to get this water to Charleville in Queensland, which is the start of the Murray Darling Basin. It would take a huge commitment and time to fix it, but we believe it’s in the interest of Australia – not just for the Australian wine industry.”

McGuigan says the Snowy Mountain scheme – a major hydroelectricity and irrigation project – is a great example of what can be achieved. He says: “It provided a huge boost for the city of Griffith, which is now the powerhouse of the Riverina.”

The industry is focused on remaining sustainable, finding ways to recycle and reclaim water and use renewable energy to power the increased refrigeration facilities required to process grapes.

Geoff Merrill explains: “Many wineries, including ours, have installed solar panels to offset the costs of non-renewable energy supply to operate adequate refrigeration systems for temperature control during and after ferment.”

Schaafsma adds that any future vineyard expansion will have to bear these factors in mind. “We’re no longer in an oversupply situation in Australia – we’re now at a point where people are thinking about more plantings and more vineyards. Being sensible and thinking long term about what’s sustainable is vital,” he says.

If water supply is not taken into account, in areas where it is strictly controlled, crops can fail, explains Braydon. “Where permanent or temporary water is available, it is extremely expensive, significantly increasing input costs and final product costs. In the extremes, where water is not available or simply too expensive for a grower to deem viable, vineyards can be left without irrigation and the crop will fail,” he says.

This feature first appeared in the May 2019 issue of the drinks business magazine.