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

Patrick brothers who shaped modern hockey also tried, but failed, to remove violence

New history thesis shows efforts to sell a “clean game” in Oak Bay

Victoria man to run marathon after overcoming rare cancer diagnosis

Nigel Deacon was diagnosed with ocular melanoma in 2010

Burger sales bring in $5,000 to build Imagination Libraries in Greater Victoria

United Way of Greater Victoria and Big Wheel Burger team up to get kids reading

‘Each step is a prayer’: Ojibwe man will walk from Hope to Saanich for Indigenous healing, reconciliation

James Taylor departs Sept. 20, returns to Saanich in five days for sacred fire

Greater Victoria businesses come together to help Island kids

Langford Lowe’s raises funds for youth mental health all month

QUIZ: A celebration of apples

September is the start of the apple harvest

POLL: Do you plan on allowing your children to go trick or treating this year?

This popular annual social time will look quite different this year due to COVID-19

Ferry riders say lower fares are what’s most needed to improve service

Provincial government announces findings of public engagement process

Supreme Court Justice Ruth Bader Ginsburg dies at 87

The court’s second female justice, died Friday at her home in Washington

Comox Valley protesters send message over old-growth logging

Event in downtown Courtenay was part of wider event on Friday

VIDEO: B.C. to launch mouth-rinse COVID-19 test for kids

Test involves swishing and gargling saline in mouth and no deep-nasal swab

B.C.’s COVID-19 economic recovery plan: Top 5 things you need to know

Jobs training, tax incentives for employers to hire staff and more

Young Canadians have curtailed vaping during pandemic, survey finds

The survey funded by Heart & Stroke also found the decrease in vaping frequency is most notable in British Columbia and Ontario

Most Read