Australia’s most popular varieties suited to cooler climates – shiraz, chardonnay, cabernet sauvignon, pinot noir and sauvignon blanc – may not be as easy to grow as temperatures increase, he adds.

Rainfall also plays a significant role in wine production. Since 1970, rainfall in Australia’s south-west from April to October has declined 16 per cent, while in the south-east rainfall has dropped 12 per cent in the same months since the 1990s. Looking ahead, rain events are likely to become more intense, compounded by climate drivers like La Niña, and an atmosphere that can hold 7 per cent more moisture for every degree of warming.

“We would have [weather] events – and this is where they talk about climate change – you expect to see once every 10 years, you might have a bad frost or a really wet year,” says Chambers. “We’re now getting them back to back or more frequently.”

Dr Christopher Davies, CSIRO team leader at Agriculture and Food, says hail, unseasonal rain and temperature fluctuations present a challenge for wine producers. They can lead to an increase in botrytis (which strips colour, turning wine from red to orange) or mildews which affect photosynthesis and reduce wine quality.

For NSW’s Hunter Valley, analysis from Wine Australia’s Climate Atlas found mean rainfall during growing seasons from 2081 to 2100 is expected to be roughly 55 millimetres more than the 1997-2017 mean. Temperatures during the same time period are expected to increase by 3 degrees. Similar changes are expected in Mudgee and Orange.

By contrast, in Victoria’s wine region of Rutherglen mean rainfall in those growing seasons will be 20 millimetres less than the 1997-2017 mean. Temperatures are likely to climb by 3.4 degrees in the same period. In the Yarra Valley, the mean rainfall could decrease by 66 mm, while temperatures are forecast to increase by 3 degrees.

Before 1998, the Chambers’ 25-hectare property was not irrigated at all, relying on annual rainfall. “We’re [now] heavily reliant on irrigation to keep the vines healthy and viable through the whole heat spell.”

Adaptation and mitigation

Dr Liz Waters, Wine Australia’s general manager of Research, Development & Adoption, says the industry has been adapting to a changing climate for more than a decade: “The beauty of wine is that it reflects the area it is grown in and [its] climate.”

The focus for the industry now is to continue evolving to deal with new challenges. Growing varieties better suited to warmer climates is just one strategy.

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NSW Wine Industry Association president Mark Bourne says varieties from the Mediterranean are better at holding their acid in extreme heat and handling drier conditions. Italian white wine fiano and tempranillo, a Spanish variety that makes a full-bodied red, have become more popular in the past few years for this reason and people are willing to pay for them, he says. (Chambers’ vineyard now features tempranillo.)

In NSW’s Central Tablelands region, See Saw Wine co-owner Justin Jarrett has vineyards at 700 metres, 800 metres and 900 metres above sea level to capture a range of different climates. For every 100 metres, the temperature gets about 1 to 1.5 degrees warmer, he says.

When Jarrett and wife Pip started their winery 25 years ago, they grew sauvignon blanc and riesling grapes in the lower vineyard and found the same grapes in the highest vineyard failed to thrive. But as the years have gone by and the climate has warmed, the couple has stopped using the 700-metre vineyard for their white wine, which now prefers higher altitudes.

The other notable change is that the harvest season has shrunk from 8-12 weeks to six.

“Harvest time is the moment of joy for all farmers, it is when you look at your year’s work and you go, ‘wow, we’ve made it’,” says Jarrett.

“You think to yourself, ‘if I can maintain this for the next 20 years, it will be very exciting’ … But what you see today can’t be what is happening in 20 years’ time.”

The pair have started growing other types of crops between the grapevines, such as turnips and peas to increase carbon in the soil, and are determined to make the business carbon-positive in the coming years.

‘If you’re not sustainable, consumers aren’t going to drink’

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Despite growers’ efforts to introduce new varieties, one key factor remains outside their control: consumer tastes.

Australians aren’t yet familiar with fiano, albarino or tempranillo the way they are with shiraz or sauvignon blanc. Davies says what is particularly interesting about Australians’ drinking habits is they are more drawn to the variety of grape and the region, rather than the winery. This is at odds with most European consumers, who tend to care about the chateau or vintage.

But the new range of varieties is something the industry is confident consumers – especially younger ones – will embrace with open arms, particularly if they know it’s been made sustainably.

“Consumers actually want us to start making that change. They look at your brand values,” says Battaglene. “If you’re not looking to become sustainable, then consumers aren’t going to drink your product.”

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The national wine industry is in the process of developing an emissions roadmap to set achievable reduction targets and help the industry get there. The sector has a goal to have net zero carbon emissions by 2050, but wants to get there sooner than that.

For Chambers, the emphasis on sustainability is much more than just a marketing ploy: “It’s getting to the point [where] no longer is somebody’s word good enough. You need to have some other certification to potentially back those comments up. People are aware of greenwashing issues.”

Chambers Rosewood is working towards gaining certification, which Chambers says is a formalisation of practices he has already implemented.

For his part, Jarrett remains hopeful for the future of the wine industry. “In Australia, the agriculture industry has been a great adapter and I think we will continue to be,” he says. “We’ve got these [climate] problems … but what matters is what we are going to do about it.”

When asked what his favourite wine is, he laughs, asking: “Which is your favourite child?”

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