Will climate change wreak havoc in the Napa Valley, home to world-renowned vineyards and wineries, or will farmers simply adapt?
These are some of the questions raised recently by a climate change study by Stanford University scientists that concluded that premium grape-growing acreage may shrink by as much as 50 percent over the next three decades because of global warming.
The report follows a 2006 climate change study that projected that more than 80 percent of premium wine grape acreage in the country could be unsuitable for some varietals by the end of the 21st century.
Napa Valley grapegrowers and vintners agree that climate change is happening at the global level, but they believe the Napa Valley will continue to produce premium grapes. Recent growing seasons have been particularly cooler than average, they note.
Napa grapegrowers will adapt to climate change and keep making fine wines, Steve Matthiasson of Premiere Viticulture and Matthiasson Wines said this week. He does not anticipate huge changes anytime soon, he said.
“I don’t doubt any of their data or modeling, and I appreciate them tackling the important issue of climate change,” he said of the Stanford study. “But I think we are much more resilient here in Napa than this study supposes, and we’ll be able to adapt to the changing climate and continue to make world-class wine without losing land to production.”
Farming techniques change with time, many noted. Growers can leave more leaves around the fruit to protect the berries from high temperatures, irrigate in a way that produces stronger roots or change trellis systems.
Jon Ruel, vice president of the Napa Valley Grapegrowers and director of viticulture and winemaking at Trefethen Family Vineyards, said the Napa Valley is committed to grow world-class grapes.
“The good farmers are those who can adapt and farm in real time,” he said, referring to the weather changes. “We’ve never had an ‘average’ year,” he said.
“I’ve got to farm for this year’s weather,” Ruel said.
Terry Hall, communications director for the Napa Valley Vintners, said the Napa Valley has not warmed substantially, referring to a recent study by other scientists that used data from the Napa Valley.
Hall and others said the Stanford study relied on average global temperatures instead of focusing on what’s going on in the Napa Valley, noting that one of the official weather station at Napa State Hospital is next to an air conditioner.
“We’re not currently experiencing climate change in terms of what we drink in our wines,” Hall said.
The study focused on possible temperature changes over the next three decades in premium wine-producing areas, including Napa and Santa Barbara counties in California and Yamhill County in Oregon’s Willamette Valley.
The study is based on the assumption that there will be a 23 percent increase in greenhouse gases by 2040, which could raise the average temperature by
1.8 degrees Fahrenheit, according to a press release from Stanford.
“One of our motivations for the study was to identify the potential impact of those changes, and also identify the opportunities for growers to take action and adapt,” co-author Noah Diffenbaugh, an assistant professor of Environmental Earth System Science and a fellow at the Woods Institute for the Environment, said in a press release.
“We’re neutral scientists that are trying to understand how the world works,” Diffenbaugh said in a followup interview.
The study also found that cooler parts of Oregon and Washington states could see an increase in premium grape-growing acreage.
Harry Peterson-Nedry, a grapegrower and winemaker in the Willamette Valley, known for its pinot noirs and chardonnays, said the cool Oregon valley is the canary in the coal mine, given its cool temperatures.
“Will the Willamette Valley become the new Napa Valley? If, by that, you mean well-known for high quality and recognized as the best place to grow certain varieties outside of their European homes, and at times rivaling those standards if not surpassing them, I’d say we’re working on it,” he said.
He likes to think that the Willamette Valley is to pinot noir what Napa Valley is to Bordeaux varieties in the New World, he said.
“Others will have to answer for the Napa Valley. We respect what has been done there, but we don’t actually want to become the Napa Valley, any more than the Napa Valley wants to be the Willamette Valley — we’re each comfortable in our own skin,” he said.