Wine-grape growers in California and around the world will be forced to move their vineyards north to cooler environments within the next few decades as climate change causes temperatures to rise, conservation biologists say in a study published last week.
Think Yellowstone pinot noir or Château Yukon cabernet.
Not that those are likely new venues for high-end premium grapes, but a new analysis warns that the world's warming climate will put new strains on water supplies for vineyard irrigation. And without planning, the scientists warned, any movement to the north by grape growers into critical habitat will pose new threats to wildlife.
For example, the trends could affect the Modesto area's giant wine companies, which mainly use San Joaquin Valley grapes but also reach into coastal regions.
The analysis by a team of international researchers, published online in the Proceedings of the National Academy of Sciences, indicates that California's coastal vineyards are least likely to be at risk because of their proximity to the Pacific Ocean, which moderates the climate.
But in the San Joaquin Valley, as well as in the world's warmer grape-growing regions, water supplies will be heavily stressed as growers are forced to compete for irrigation water with other crop growers, said Lee Hannah, a biologist and climate specialist with Conservation International who led the study.
At the current rate of climate change, vineyard owners by 2050 could be pushing into California regions now considered unsuitable for wine growing, such as the higher slopes of the Sierra Nevada and the state's northern redwood forests, Hannah said.
Only careful planning will ward off conflicts between wine-grape growers and wildlife defenders, said Rebecca Shaw, a climate policy analyst with the Environmental Defense Fund.
The "Yellowstone-Yukon corridor" is a typical region that is "unsuitable" for wine-grape growing, but where vineyards could become widespread in the next 40 years, according to the scientists' analysis.
Wine is made in the Yellowstone area now, and some farmers grow grapes there, but Montana's eight licensed wineries specialize in making wines mostly from cherries, rhubarb, blueberries, pears and other fruit, according to the Montana Commerce Department.
In Australia, Hannah said, many grape growers are expanding their vineyards south into Tasmania, where cooler climates previously have inhibited full ripening, but where global warming is making the region a better fit for wine.
And in South Africa, wine-grape growers are planning moves to higher altitudes for their expanded vineyards, Hannah said.
In Napa, noted wine consultant Steve Matthiasson, who produces wine from his family vineyard, called the analysis "a great report."
"I agree with it. It's right on," he said. "It's time we think hard about it so we growers can move out of the abstract. Remember, grapes are very adaptable. Even now, they're growing grapes in the Coachella Valley, where it's really hot."
Many growers in the San Joaquin Valley have reduced water demand by irrigating only when truly needed. This can enhance the quality of the grapes if done properly, a benefit for wineries trying to show that the valley can produce some good wines.
Growers can adapt to global warming, Matthiasson said, by planting drought- tolerant rootstocks and by irrigating longer but less frequently so "root zones" go deeper. Vineyard rows can be shifted to allow leaves to give more protection to ripening grapes, he said.
"Irrigation is our insurance policy," Matthiasson said, "but if at some time we can't grow grapes in California, then we'll have a lot more to worry about." Modesto Bee staff writer John Holland contributed to this report.