Fire and Wine

As grape growers face climate-change-fueled wildfires and increasingly hotter temperatures, what’s next for the wine industry remains murky.

Fire and Wine
Wildfire ravages California wine country vineyard. Photo courtesy Getty.

Australia’s bushfires were still raging out of control when Mike Jaeger’s plane touched down in Sydney this winter.

The president and CEO of California-based Cakebread Cellars shuddered over the loss of human and animal life, the homes and businesses destroyed, including some Australian wineries.

It wasn’t long ago that Jaeger himself had witnessed the catastrophic effects of wildfires on the wine country back home, so he knew what his vintner friends on the opposite end of the world were now facing: millions of dollars needed to rebuild, with potential millions more if smoke tainted their grapes.

And fires are just the beginning. Global climate patterns are changing as carbon dioxide produced by fossil fuels warms the planet. Heat, drought, and fiercer storms are all predicted byproducts of the climate crisis.

Without a reduction in the production of carbon dioxide, half of today’s wine regions will not be able to grow the varietals we drink today, according to a study published this winter in the Proceedings of the National Academy of Sciences.


Around the world, scientists say the domino effects of climate change—more periods of extreme temperatures, years of drought, drier vegetation—are fueling more frequent and bigger infernos.

Between 2000 and 2019, more than a million acres burned in the wine-growing California counties of Napa, Mendocino, Lake, Marin, and Sonoma. That’s more than the total burned in the region over the 49 years prior, according to the Los Angeles Times.

Wildfire burned wine barrels
Barrels burned in the Tubbs Fire in California. Will global climate change make this an increasingly common scene? Photo courtesy the Associated Press.

And those figures do not include recent burns in other grape-growing regions, including the Central Coast counties of Santa Barbara and Monterey, or in Washington state.

Of course, fire in wine country doesn’t always affect the wine: It depends on when in the grape-growing season a blaze sparks. But even if smoke doesn’t taint grapes on the vine and flames don’t burn through barrels, the people who live and work in the area can find their lives and businesses upended.

When the most destructive fire in California history, the Tubbs Fire of October 2017, tore through the region near Santa Rosa, Battaglini Estate Winery vineyards’ zinfandel and petite syrah grapes—from some of the oldest vines in the state, brought over from Tuscany in 1885—were waiting to be processed. The Sonoma County fire marshal ordered an evacuation of the area.

“We had already picked the crop, but it was sitting there for 13, 14 days,” recalls Giulio Battaglini ’83, who helps run the business with family, including brother Dino Battaglini ’93. “We could not get to it in time, and it spoiled.” The Battaglinis lost an entire year’s worth of production.


It’s not just burns and evacuation that winegrowers worry about. Smoke is another disrupter. It causes an insidious defect: an off-taste or smell that may not reveal itself until the wine has been bottled.

The financial losses from smoke taint are substantial, and they’re why the industry is closely watching lawsuits filed in 2019 by two Sonoma-based wineries, Kunde Family and Vintage Wine Estates. Their insurance carriers refused to cover smoke damage estimated at $7 million and $12 million, respectively, from the 2017 fires. Meanwhile, the threat of future fires has also sent grapegrowers’ insurance rates soaring with increases as high as 200 to 300 percent. Some carriers have dropped coverage altogether.

“So if you cannot afford insurance and you have a loss, there aren’t many businesses that can weather that,” says Steve Tamburelli ’87, a former CEO at Stags’ Leap Winery and Clos du Val, now co-owner of Vinitas Wine Group consulting firm.

Jaeger, the Cakebread Cellars CEO, says wildfires are “a critical variable to deal with,” so the industry is focused on coming up with solutions to address potential damage like smoke taint. “We believe that the frequency of fires is increasing,” he says, “so we’d better have a good understanding about the impact of smoke and its effect on vineyards and our winemaking production.” While specialists are researching ways to correct for smoke taint, there is still no perfect solution.

Even in the absence of the infernos, though, changing climate trends are already impacting the wine business.


Vineyards blanketed in morning fog. Cool temperatures. These are the conditions that helped make southern Napa County, Napa—ideal for growing chardonnay grapes.

Over the years, though, the temperature has climbed— about 1.3 degrees Celsius on average since the 1800s, according to a statistical analysis by The Washington Post that relied on data from NASA and the National Oceanic and Atmospheric Administration.

The same analysis shows average temperatures have increased 2.3 degrees Celsius in Santa Barbara County. That’s above the target for limiting the average increase of global temperature set forth in the Paris Climate Accords of 2016.

So what does heat do to wine?

It disrupts the precarious combination of soil, water, and weather that makes up a wine’s terroir—the environment-driven flavor and mouthfeel. The balance is so delicate that, for example, grapes are often grown on one side of a hill but not the other to best take advantage of coastal fog.

When it’s hotter, grapes ripen more quickly, intensifying the fruit’s natural sugars and changing the flavor. Think of the difference between sweeter white zinfandels or muscats compared with drier cabernet sauvignons or syrahs.

When he was just starting out in 1980, Paul Dolan ’72, a fourth-generation winemaker who spent almost three decades at Fetzer Wines, says he was “super happy” producing a cabernet at 23 or 24 percent sugar, and a 13.8 percent alcohol content. Today, Dolan runs Truett-Hurst in Healdsburg and says because of more “heat degree days”— how much heat a grape vine is exposed to during a growing season—he is struggling to keep the sugar level below 30, and alcohol content to 16 percent.

As it happens, these riper grapes have translated into denser wines that are popular. But as the years go by and temperatures continue to climb, Dolan says already hot areas like the Central Valley—where more than 107,000 acres of wine grapes currently grow—could struggle.

Experts say the Central Valley will hit more boiling temperatures more frequently because of human-caused climate change. A 2019 report by the Union of Concerned Scientists forecasts the region will experience an average of more than 25 days per year with a heat index above 105 degrees Fahrenheit. Given that the Central Valley produces 40 percent of the nation’s fruits and nuts, that heat will have a profound impact on agricultural workers and California-grown produce beyond grapes for wine.

Tubbs fire
The Tubbs Fire of October 2017 burned parts of Napa, Sonoma, and Lake Counties. At the time, it was considered the most destructive wildfire in California history, burning more than 36,000 acres and killing 22 people. But a year later, the 2018 Camp Fire in Northern California’s Butte County surpassed those damages, burning nearly 154,000 acres and killing at least 86 people. Photo courtesy California National Guard via Flickr.


Warm is relative. A temperature change that could make some places in California too hot for grapes might open up growing opportunities in other places. Ready for a winery tour in Michigan?

“They have something like 3,000 acres of wine grapes, which would have been impossible 30 years ago” in the Great Lake State, says Ed Maurer, SCU professor of civil, environmental, and sustainable engineering. “Global warming has created possibilities for wine productions in places where it was once not possible.”

But terroir is made up of all of the environmental inputs that go into making a great wine, from climate to local weather to soil types. Winemakers can’t just pick up and replant their vineyards in a different microclimate and expect to put out the same product.

“As the world gets warmer, the appropriate place for growing grapes would be migrating northward,” says Maurer. Unfortunately, “the soils don’t migrate with it.”

Still, some growers are finding success up north.

In Oregon’s Willamette Valley, Vincent Fritzsche ’91 has been making pinot noir, chardonnay, pinot blanc, gamay, and even red wine from pinot gris grapes under the Vincent Wine Company label since 2009.

Like many vintners, Fritzsche does not own a vineyard; he buys the grapes from several growers he knows. Lately, he has noticed some growers planting vines in higher elevations, toward the Oregon coast—and even those are on north-facing slopes that experience less intense heat.

“These are areas that had previously been considered too cold to plant vines,” says Fritzsche. “More and more, people are looking for sites that will not ripen too quickly.”


As the fourth-largest wine-producing country in the world—85 percent of it made in California—with a $220 billion annual economic impact, the U.S. wine industry is keenly aware of what’s at stake with global warming.

That’s why, says Vinitas Wine Group’s Tamburelli, academic researchers in the Western U.S. are focused on adding small genetic variations to produce heat-resistant grapes, while achieving the same wine-producing outcomes.

Switching up what’s growing is also a potential solution. For example, heat-tolerant tempranillo, a black grape variety used to make full-bodied red wines, is getting attention from growers far from its native Spain. In 1998, the USDA didn’t even track the amount of tempranillo planted in California. By 2018, the agency found nearly 1,000 acres.

At Storrs Winery & Vineyards in the Santa Cruz Mountains, Pamela Bianchini-Storrs MBA ’91 and her husband, Stephen, enjoy the cool temperatures that coastal proximity offers to grow their chardonnays and pinot noirs. But, she says, they are not immune from warmer temperatures that have at times led to earlier-than-planned grape harvests.

For now, they will monitor temperature changes; a wine industry forecaster recently told them that they should be in good shape for the next decade. And what then?

“We could plant a Bordeaux varietal like merlot,” Bianchini-Storrs says. “Right now, it’s too cool to go there, but we are optimistic. We have choices moving forward.”

Whether through clonal adaptation, changing varietals, planting rows of grapevines in more strategic directions, or experimenting with canopies to better shade vines, “we are trying to find a way to make our existing vineyards survive this,” Tamburelli says.

Tempranillo grapes
Within 20 years, the USDA found about 1,000 acres of tempranillo grapes—a heat-tolerant varietal native to Spain—had been planted in California by 2018. Photo courtesy Wikimedia Commons.


Every year for the past two decades the U.S. wine industry’s most authoritative assessment of industry conditions comes from Rob McMillan MBA ’88, founder of the Wine Division at Silicon Valley Bank. While the report highlights plenty of issues faced by the industry, climate is mentioned in passing.

Back in 1998, when he moved to Napa Valley, McMillan remembers seeing vineyards plagued by frost, and the massive fans placed nearby to circulate warm air and prevent further damage.

“But, you know, we really don’t have many of those days, just from observation,” he says. “It does seem like we have our fires, and it does seem like we have our droughts.”

While he is aware that some grape growers are replanting in other areas, McMillan cautions against making a too-hasty decision to rip out vines for supposedly greener agricultural pastures. After all, he says, most healthy vineyards last 25 years.

“What if you take action and you’re wrong, and you screw up your business?” asks the banker, who remembers a wine grower in financial straits who replanted his vineyard with Jerusalem artichokes, certain he would corner that market, only to go bankrupt.

It’s also expensive. On average, according to Tamburelli, replanting costs between $30,000 to $80,000 an acre, depending on how densely the grapevines are planted.


Many wineries are now adopting growing techniques that use less carbon.

Some plant legumes as cover crops between and under the rows of vines, or use sheep instead of gas-powered tools to manage weeds in the vineyard.

Grape vine bud
Hope remains: The wine industry looks to become part of the solution to climate change, as many wineries and growers begin to pledge to reduce their own carbon emissions. Photo courtesy Shutterstock.

In 2019, International Wineries for Climate Action was born when Barcelona’s Familia Torres and Santa Rosa-based Jackson Family Wines, where Jennifer Jackson Hartford J.D. ’82 is co-proprietor, launched the group for the environmentally committed. Members pledge to reduce their carbon emissions by 80 percent by 2045.

To join, wineries must be powered by 20 percent on-site renewable energy, have an outside group develop a baseline for their emissions, and demonstrate at least a 25 percent reduction in emissions from that baseline year. Those requirements mean the wineries already have had to make efforts to reduce their reliance on fossil fuels.

It is no small number of wineries that have pledged. Jackson Family Wines includes 40 wineries representing North American, European, South African, and South American vineyards—including Galerie, where Gianna Ghilarducci Kelly ’97 is winemaker, and Stonestreet Estate Winery, overseen by Christopher Jackson ’11.

It’s efforts like these that give Dolan hope, despite his worries.

Fifteen years ago, the veteran winemaker was already talking to anyone who would listen about climate change and its impact on wineries. As president of Fetzer, he helped it become the nation’s largest organic wine company, and he hasn’t stopped advocating practices he believes help make vineyards more resilient to drought and climate change.

As he looks to the future and the challenges ahead, Dolan believes the wine business can draw on its past leadership.

The wine industry has been instrumental in developing the conversation around sustainability, “more so than any other industry in the world, and the California wine industry specifically,” he says.

In our wine lies hope.

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