Cabernet Sauvignon wine grapes that are almost ready for harvest are held at Wente Vineyards in Livermore, Calif. in this Oct. 4, 2019 photo. THE CANADIAN PRESS/AP/Terry Chea

Swapping grape varieties can help winemakers adapt to climate change: UBC study

Report says 56% of wine-grape-growing regions would be lost if global climate warms by 2 C

Adopting drought and heat-tolerant grape varieties could help winemakers grappling with the effects of climate change, says new research from the University of British Columbia.

Wine grapes are particularly sensitive to temperature, which means many growers have already been feeling the effects of a changing climate for decades, said Elizabeth Wolkovich, a professor of forest and conservation sciences and senior author of the report released Monday in the Proceedings of the National Academy of Sciences.

“You’re looking for this perfect variety that will match to the length of your growing season, so that it ripens just at the end, when you get the perfect climate,” said Wolkovich, adding that the good news is winemakers can adapt their practices to keep wine flowing.

The Intergovernmental Panel on Climate Change has warned that if the current trend continues over the next decade, the world is on track to warm by more than 1.5 C.

The report published in the official journal of the National Academy of Sciences forecasts that 56 per cent of regions that grow wine grapes would be lost if the global climate warms by 2 C.

“When we say it’s unsuitable, we’re saying in at least 25 per cent of a 20-year period, we don’t think they will be able to harvest a good quality crop,” said Wolkovich.

In some regions, climate change could mean there is too much precipitation, which can lead to disease. In others, she said hot temperatures could mean grapes with poor sugar-acid ratios.

But the researchers found that losses of suitable grape-growing areas declined when they allowed for the turnover of cultivars, or grape varieties produced by selective breeding.

There are more than 1,100 wine grape cultivars planted around the world, she said, and their main differences include how much heat they need, how drought-tolerant they are and how quickly they ripen.

Allowing for cultivar diversity, in a 2 C warming scenario, the report predicted a loss of 24 per cent of current wine growing regions, compared to 56 per cent without cultivar diversity. However, in a 4 C warming scenario, the benefits of cultivar diversity were muted, the study found.

Grape growers are already using adaptation strategies, such as shade cloths and misting systems, to cool down the plants. When those aren’t enough, that’s when cultivar diversity comes in.

To make their predictions, the researchers drew on long-term French records for 11 diverse grape varieties including Cabernet Sauvignon, Chardonnay, Merlot, Pinot Noir, Riesling and Sauvignon Blanc. They compared the plants’ phenology, which refers to the timing of a plant’s developmental stages, such as bud burst and ripening.

Using temperature data and climate modelling, they built models that predict how grape varieties would fare in other regions with 98-per-cent accuracy, said Wolkovich.

In Canada, growers are often limited by climate and plant comparatively few varieties, she said, adding that they face additional regulatory hurdles when importing grape varieties from outside the country.

But the northern hemisphere is warming quickly, she said, which could mean it will be easier to grow certain varieties, such as Pinot Noir, in places like Vancouver Island.

READ MORE: B.C. wineries remain optimistic about quality of grape harvest

Both growers and consumers will have to get on board if cultivar diversity is to take off, she said, noting that consumers in Canada and the U.S. tend to emphasize variety rather than the region their wine comes from.

“Growers want to know that consumers are willing to try different varieties … and consumers can’t really show that they’re willing to try a different variety until they’re offered it.”

These aren’t painless shifts for grape growers and winemakers, said Wolkovich.

Wine grape plants must grow for around five years before they’re ready for harvesting, she said, and the decisions growers make now are crucial as they try to predict and prepare for the effects of climate change in their regions.

Brenna Owen, The Canadian Press

Like us on Facebook and follow us on Twitter

BC Wine

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Best of the City: Cannabis store’s customer service impresses

Mood Cannabis Co. finishes second for Best Customer Service in reader survey

Best of the City: Live-streaming in quarantine

Arts and entertainment community resilient in the face of a pandemic

Tour de Rock arrives in Nanaimo, now it’s off to the next station

Cops for Cancer team completes Nanaimo section of Vancouver Island cycle relay

Best of the City: Burger joint is tops in Nanaimo

Newly opened Top Notch Burgers Grill and Lounge voted Best Hamburgers

Best of the City: Breathe easy

Modo Yoga wins Best Yoga Studio category during challenging time for health and wellness businesses

Tour de Rock arrives in Nanaimo, now it’s off to the next station

Cops for Cancer team completes Nanaimo section of Vancouver Island cycle relay

Best of the City: This year’s winners

Nanaimo News Bulletin presents full results of our 2020 Best of the City readers’ survey

Vancouver Island couple’s sheep farm dream disrupted by high lumber price

The solar powered farm project in Sayward will be set back by three years if the lumber price continues to remain high

The holiday everyone needs this year: Vote for your favourite in Fat Bear Week 2020

Voters will get to decide who gets to take home this year’s most coveted prize

LETTER TO THE EDITOR: Mask rules inconsistent

Letter writer says he won’t pay fine for violating COVID-19 Related Measures Act

End of CERB means uncertainty for some, new system for others

As of a week ago, the CERB had paid out $79.3 billion to 8.8 million people

Horgan, Wilkinson trade barbs over MSP premiums, health care at campaign stops

Horgan called a snap election for Oct. 24 earlier this week

Victoria-area RCMP locate high-risk sex offender thanks to help of taxi cab driver

Scott Jones wanted on a Canada-wide warrant, ‘a risk to women and girls,’ police say

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

Most Read