Napa, Calif. — Droughts. Soaking winters. Heat waves. Wildfires. The last several years have whipsawed West Coast winemakers such as David Graves, who produces that oh-so-delicate of varietals, pinot noir.
It is also prompting vintners to ponder whether climate change — once seen as distant concern — is already visiting their vineyards.
“It’s a different ball game,” said David Graves, co-founder of the Saintsbury winery in Napa. “A lot of my colleagues think they can manage around this and stay in a business-as-usual mode. I don’t tend to believe that.”
Increasingly, winemakers in places such as Napa, California’s Central Valley and Oregon’s Willamette Valley are acknowledging that climate change poses not just a future risk, but a clear-and-present trend. Warmer days and nights, combined with more extreme weather events, are forcing many vintners to adjust their harvest dates and how they produce wine.
Their observations are not uniform across the West Coast. The wine regions of California, Oregon and Washington are a melange of micro climates, some of which have seen little change the last several years. But a heat shift has been documented in several locales, worrying winemakers who have millions of dollars invested in their vines and terroir.
Harry Peterson-Nedry, a winemaker in Oregon’s Willamette Valley, has been tracking climate records for decades. During the growing seasons of 1997 to 2017, temperatures in the Willamette town of McMinnville increased 17 percent compared to the 1961-1990 period, he said, based on the number of degree days recorded, a measure of accumulated heat.
That increase means that, in the last half decade, the once-cool Willamette shows signs of moving from a Region 1 to a Region 2 wine-making area, based on an index developed by the University of California, Davis.
“It seems to really have ramped up in the last five years,” said Peterson-Nedry, a chemist and founder of Chehalem Wines. “If we see this for another five years, we will really be questioning what is going on.”
Markus Niggli, winemaker at Borra Vineyards in Lodi, Calif., has also seen a shift. Up until 2014, Borra typically harvested syrah grapes in the first or second week of October. Because of higher temperatures and faster ripening, Niggli and his team have been picking syrah in late August the last three years.
“I believe this has something to do with climate change,” said Niggli. “You look at what’s happening with the 2017 vintage all over the world — frost, hail and drought in Europe. Here it was heat and fire. We are seeing extremes we haven’t seen before.”
As Niggli notes, unusual weather appears to be influencing international production of wine, which has declined since 2013, despite increasing worldwide demand.
In a report last week, the International Organization of Vine and Wine estimated that world wine production would fall 8.2 percent in 2017 compared to the previous year, reaching its lowest point in two decades. The IOVW attributed the decline to “unfavorable climate conditions” in Italy, France and Spain, the world’s three largest producers.
Not all winemakers are complaining. In British Columbia, winemakers in the Okanagan Valley east of Vancouver are planting red wine varietals once deemed unsuitable to the region, such as merlot and pinot noir. Studies have reported that Okanagan’s wine industry will likely flourish in the decades to come.
In Oregon’s Willamette, growers once worried about their pinot noir grapes reaching full ripeness by the end of the short growing season. Now they have opposite concern — making sure their grapes don’t ripen so quickly they lose some of their delicate character.
Peterson-Nedry acknowledges that many of his recent vintages have benefited from warmer temperatures. But he’s wary of where it all could lead.
“It is like a train coming through the tunnel at you,” he said. “The light from the train may help you a bit in seeing where you are walking. But eventually you will get crushed.”
Of the major wine varietals, pinot noir is widely viewed as the most endangered by climate change. The thin-skinned grape is vulnerable to hail, late heat waves and other weather extremes.
“Pinot reacts to everything you do to it,” said Ken Bernards, owner of Ancien, a Napa-based winery that features pinot noir grown in different locales, including Santa Barbara County, the Russian River and Oregon. “It doesn’t want too much water or it makes a dilute wine. It doesn’t like to be stressed. It needs to grow on this razor’s edge where it stays in balance to reach its perfect expression.”
Over the last 30 years, the San Francisco Bay has helped cool Bernards’ Napa vineyards in Coombsville and Carneros by shrouding the region in fog, especially when the Central Valley is blazing hot. “I am banking on that to continue,” he said.
Yet even Bernards is seeing wider ranges in harvest dates and heat events than previous decades. And when wildfires swept through Napa and Sonoma counties last month, they torched the ridge tops above his Coombville vineyards and destroyed several nearby wineries.
“It was very dangerous,” Bernards said recently, sitting under an oak tree looking up at blackened hillsides. “I was standing here looking up at the ridge and it was just glowing red.”
Fanned by winds of 50 mph or more, the October blazes destroyed or damaged roughly two dozen of the 1,200 wineries in California’s wine region. Thousands of families lost their homes, including many employed in the wine industry. Heavy smoke in the vineyards also raised concerns of “smoke taint” in grapes that hadn’t already been harvested, including a portion of the cabernet sauvignon crop.
Some winemakers, particular large producers, have recently started diversifying their holdings, buying wineries in Washington state, Canada and cooler climates in the southern hemisphere, such as Chile and New Zealand. That’s led to speculation they are trying hedge the risks of climate change — but it’s a topic they are reluctant to discuss.
Gregory Jones, director of wine education at Linfield College in Oregon, said the wine industry in consolidating and buying new properties for a variety of reasons. But climate change is part of the equation, he said.
Jones said he knows of a range of wineries that are adjusting their grape growing and winery operations to counter higher temperatures, but prefer not to make those modifications public.
“Wineries are being very cautious with the climate change issue because they don’t want to bring attention to quality,” said Jones. “It is a sensitive issue.”
Jones, along with Stanford University’s Noah Diffenbaugh and other scientists, published a peer-reviewed study in 2006 that projected that climate change, by 2100, would reduce the U.S. area suitable for premium grape growing by up to 70 percent. The study, published in the Proceedings of the National Academy of Sciences, caused a furor in California, the nation’s number one wine-producing state, with roughly $32 billion in retail revenues each year.
In response, the Napa Valley Vintners organization asked scientists from the Scripps Institute to prepare their own report on the valley’s future. That 2011 report, not peer-reviewed, projected much-less dire warming in Napa, prompting the trade association to highlight the uncertainties of climate change.
“Since 2006, media outlets around the world have been saying that the global wine industry is doomed,” the Napa Valley Vintners says on its website. “The headlines belie the fact that there is a lot that is unknown about climate change as it affects the wine industry and particularly Napa Valley.”
Peterson-Nedry, the Oregon winemaker, said that he once was greeted with blank stares at wine conference when discussing the implications of climate change. Not anymore.
“The disbelievers are much fewer than they used to be,” he said. “People are realizing that data is data. Facts are different than politics.”
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