In a Warming World, What Happens to Wine?

As global temperatures rise, viticulture will be forced to change, adapt, or disappear. 

The sky is softly spitting in the Rheinhessen, in Central Germany, as a young winemaker in black Adidas and a backward baseball cap shows me around his vineyards. In 2015, winemakers in Germany complained of not enough rain. Last year, it was too much. Tight bunches of green buds hang in a constellation amid the foliage covering gnarled vines, days away from splitting open to reveal tiny white blooms. Flowering, a crucial time in the vineyard, is a major indicator of how good the harvest will be. I ask the winemaker, Jason Groebe of Weingut Bergkloster, if the season is rolling out according to schedule and he assures me it is. Being 25, he wasn’t around to experience the harvest arriving weeks later just decades ago.

A colleague of his, in the Rheingau, is old enough to remember how things once were. A good harvest was measured by the grapes’ ability to ripen, which in Germany could be a gamble. Christian Ress, who is now at the helm of his family winery, Balthasar Ress, recalls that his father and grandfather regularly coped with poor harvests. As temperatures inch up each year, achieving ripeness is no longer a struggle. Ress pours me a glass of his Hallgarten 2015, a subtly off-dry Riesling with bright acidity and easy grace, as he explains its provenance: a vineyard once deemed second-tier (because of its location high up on a hill where it used to be too cool for grapes to ripen reliably) that’s now one of the winery’s most prized sites.

Climate trends demonstrate an increase in average temperature during grape-growing seasons around the world. 
Illustration: Laura Sant / Source: Southern Oregon University / Dr. Gregory V. Jones

In recent years, researchers have estimated that the wine map as we know it could be transformed by the year 2050. Much of Europe, from Bordeaux to Tuscany, as well as parts of Australia and California, could be too hot to grow grapes for wine production by then, and the regions that will thrive in future generations aren’t even on today’s wine map. Those high-acidity dry Rieslings you’ve grown to love? They’ll no longer come from the Mosel, which will be more amenable to Merlot, but from parts of Germany that don’t even make wine yet. Meanwhile, countries you might never have associated with wine at all, from the U.K. to central China, could be ripe for cultivation. These projections have caused a degree of panic within the wine industry. It’s considered as much a PR problem as a threat to a way of life. But many have been quick to dismiss the threats as alarmist.

“The reality is, most of us live vintage to vintage,” says Chris Howell, the winemaker at Cain Winery in Napa Valley, speaking slowly with a hint of a California hippie’s twang. “We have a hard time thinking 20 years from now. We should be thinking generations ahead, but what I’m really thinking about is what the vintage will be like in 2017.”

But the 2017 vintage will already see the effects of climate change. In some parts of California last year, tourists who’d planned their trips for September or October to catch the harvest were disappointed. A perfect storm of drought, wildfires, and warmer-than-usual temperatures along the West Coast resulted in one of the earliest harvests on record. Grape pickers could be seen out in the vineyards in the warmest parts of the state as early as July.

Climbing temperatures are causing grapes to ripen faster, resulting in sugar-ripeness without flavor complexity or acidity. High sugar levels generate higher alcohol contents and bigger, richer wines—wines that can lack elegance and freshness. Yes, you want grapes to grow sweet, but they must retain acidity. Still, while experts agree that warming is at least in part responsible for riper wines, not everybody sees this as a bad thing. (Consider, for example, the stunning rise in consumer demand, beginning in the 1990s, for big, fat, fruit-bomb wines.)

Europe's cool-climate wine regions, depicted from 1950 – 2000, include some of today's most revered appellations, including Champagne in France, the Mosel in Germany, and Alto Adige in Italy.
Illustration: Laura Sant / Source: Southern Oregon University / Dr. Gregory V. Jones

“Harvests are coming earlier, grapes are ripening sweeter and with less acid, and certain regions are experiencing aromatic and phenolic changes—you know, changes in the color of the grapes,” says Nathalie Ollat, an engineer whose lab in Bordeaux is dedicated to the ecophysiology of vines and their adaptability to drought. “But many winemakers consider that, for now, these conditions are favorable. Compared to the 1990s, they are able to more regularly produce high-quality grapes.”

Several European winemakers I spoke to expressed satisfaction with the early results of a warming climate, especially those old enough to recall a time when achieving ripeness in the vineyard wasn’t always a sure thing. Indeed, a good vintage used to be an exceptional and happy occasion. Declared maybe two or three times per decade, it was marked by an unusually warm growing season, just enough rainfall, and the absence of extreme weather like hail or frost. Now that hot summers are the new norm, eight good vintages out of ten is not uncommon. It’s led some in the wine world, including Ollat and Burgundy-based winemaker Amaury Devillard, to call this a golden age of wine production.

“I see the glass as half full,” says Devillard, a tall, dashing Frenchman who is also the president of the producers’ union for the Mercurey appellation. “The advantage [of rising temperatures] is that we have better phenolic development. It allows for grapes with an interesting balance of freshness and depth. For the moment, anyway.”

According to the French weather service Météo-France, average temperatures in France have risen 1.4 degrees Celsius (2.5 degrees Fahrenheit) since the beginning of the 20th century. In Burgundy, where the increase is a hair more modest, winemakers report milder, wetter winters, which can foster the spread of pests and disease. (As the saying goes, un hiver rude tue la vermine: “a harsh winter kills vermin.”) On the other hand, harvests are coming weeks earlier than they did just a couple of generations ago. Back then, the harvest took place in October. Now, growers can hire students for the fieldwork; it’s possible to get the job done before school starts in September. It’s a boon, Devillard says, resulting in healthier grapes because they aren’t subject to the unpredictability of fall weather.

This response may sound naive, if not absurd—like someone celebrating the weight loss caused by a disease that will one day consume him.

Despite the propensity for optimism, preparations are being made throughout France for what lies ahead. As even Devillard acknowledges, the changing climate has been a wake-up call for many winemakers, snapping them out of the doldrums of a generations-long routine. “We use more analysis in the vineyards,” he says. “Dealing with climatic changes goes hand-in-hand with the cultural changes we’re seeing in Burgundy. More people are doing organics and sustainable farming… It requires a more precise, conscientious way of working.”

Researchers in Bordeaux are conducting crossbreeding experiments. Rather than cross-pollinating the vines, they’re grafting local varieties onto rootstock varieties that may be more resistant to heat or drought. At Nathalie Ollat’s lab, more than 50 domestic and foreign grape varieties are being tested, many from climes far warmer, to determine which are most resistant to drought and high temperatures. Varieties like Syrah and Sangiovese thrive in the heat better than, say, Merlot. Given that grape varieties permitted in Bordeaux are strictly regulated, introducing new ones, even from elsewhere in France, would require not only a deep cultural shift but an overhaul of local regulations.

Climate projections for 2050 show new cool-climate wine regions in Europe—including Ireland, Sweden, and the Netherlands—and threaten to erase areas currently revered.
Illustration: Laura Sant / Source: Southern Oregon University / Dr. Gregory V. Jones

“It’s always complicated to change the rules, but it’s possible,” Ollat says. “If there is a guarantee of quality and commercial success, practices can evolve, although very slowly.”

For now, France’s winemakers are resorting to less drastic countermeasures. François Despagne, a winemaker in Saint-Emilion, reports “coming back to varieties that naturally have less alcohol, like Cabernet Franc, and working with yeasts that produce lower alcohol.” He adds: “We don’t need radical solutions just yet.”


At UC Davis, in California, radical solutions are precisely what are being explored. Researchers are using genetic mapping to breed hybrid varieties maximized for climatic adaptation. In Australia, where a 2011 report found that the harvest begins one to two days earlier each year, one wine company is investing in research into alternative grapevine clones and rootstocks, as well as selecting clones that are more drought tolerant. Treasury Wine Estates, whose portfolio includes such high-profile brands as Penfolds and Stag’s Leap, has adopted delayed pruning techniques to allow grapes optimal hang time on the vine so more complex flavors have a chance of developing. Then again, unlike most European regions where terroir is king, major Aussie brands rely on multiregional sourcing. Should an acclaimed vineyard stop producing top-quality fruit, grapes can be sourced elsewhere.

“In the New World, if we see a variety not performing well, we try a new planting site or variety,” says Greg Jones, a professor of environmental science and policy at Southern Oregon University. “But in the Old World, regional identities are based on particular varieties. The classic example is Burgundy. It really only grows two grapes. At some point, the climate will warm to the point that Chardonnay and Pinot Noir no longer perform well. Will Syrah from Burgundy in 50 years from now be the same quality as the Pinot Noir is now? These are hard questions to answer.”

At the ninth International Cool Climate Wine Symposium, a biennial event attended by winemakers and other industry insiders that took place in Brighton, England, last May, Jones lectured about the changing wine map and the adaptive capacity of cooler climates. He is a leading authority on climate change vis-à-vis viticulture, and has witnessed its effects firsthand at his family’s winery in Oregon’s Umpqua Valley. It’s still too early to predict what the harvest will be like this year, but last year, most wineries in Oregon were done by mid-October. They typically work the harvest well into November.

“In my region, as more people came to plant vineyards in the post-Prohibition era, it was very marginal,” Jones says. “From a banker’s standpoint, it was not a good investment. You might get one or two good vintages out of ten. Now, it’s a wonderfully suitable region.”

He likes to use Pinot Noir, a variety his region has come to produce so beautifully, to illustrate how deeply temperature and grape variety are linked. As diverse as the varietal can be from one region to the next, it must grow within rather narrow climatic parameters—a spectrum of just 4 degrees Fahrenheit—to be any good. A shift in average temperature of just a degree or two in a given locale could make it inhospitable to Pinot Noir. As Jones points out, certain varieties, like Chardonnay, are more flexible, growing over a wider climatic range. Others are less so. But the implications for a place where Pinot production is crucial, like Burgundy, are huge.

Every varietal has its own optimal climatic threshold. According to projections, as temperatures rise, grapes that thrive in Oregon's Willamette Valley today may not be viable by 2050.
Illustration: Laura Sant / Source: Southern Oregon University / Dr. Gregory V. Jones

The same goes for the wine industry at large. Regions that have evolved with a focus on specific varieties will be forced to consider adopting new varieties. Or, they may consider planting new, previously uncultivated sites better suited to existing varieties. Either way, it’s a decadal project requiring a comprehensive marketing strategy. Collectors who cling to the wines of certain appellations will have to either switch allegiances or embrace whatever grape variety a hallowed stretch of land ends up growing.

Or, as Chris Howell in Napa puts it, “Maybe Montrachet is so cool that you don’t have to plant Chardonnay there. Maybe you could grow some other variety and it would still somehow be Montrachet.”

The idea of simply picking up and moving is unthinkable to many European winemakers whose estates have been in the family for generations, but sloughing off the shackles of tradition to seek better growing conditions elsewhere is exactly what Jean Bousquet did. A third-generation winemaker from the Languedoc, he saw the writing on the wall—or, more precisely, the falling acidity in the wines—as far back as the 1990s. He relocated to Argentina, where he scoured Mendoza for an ideal parcel of land on which to grow grapes. His search took him higher and higher, up into the Uco Valley. On the slopes of Tupungato, one of the highest peaks in the Andes, he planted vines. At the time, many doubted him, but today Tupungato is one of the most acclaimed grape-growing regions in South America. Domaine Chandon makes wine there, as does superstar oenologist Michel Rolland. The hot days and cool nights allow grapes to ripen slowly.

“It’s becoming clear that you have to go up in the mountains to make high-end wines,” says Labid Ameri, who helped found Domaine Bousquet (and is married to Bousquet’s daughter). “We’re now looking at buying land at even higher altitude, 5,000 feet above sea level and up. People are walking away from too much oak and jammy fruit. They want freshness in wine.”

Cool-climate regions, like those at high altitude or close to the poles, are benefiting most from global warming. In Germany, for instance, more and more Pinot Noir is produced. Plantings of the local red varieties Dornfelder and Lemburger are also on the rise, as is the decidedly non-local Cabernet Franc. Britain is now able to make sparkling wine from the same grape varieties that flourish 200 miles southeast, in Champagne. Virtually unheard of 15 years ago, British bubbly is now burgeoning thanks to temperatures in southern England rising to the levels of those in midcentury Champagne. The Okanagan Valley in Canada is doing award-winning Chardonnay.

“When we start seeing German Cabernet, run!” jokes master sommelier Kathy Morgan, a Washington, D.C.–based wine educator and advisor to high-net-worth private clients looking to expand their knowledge and cellars. “Everybody’s hesitant to call it climate change. But the wines of the world are clearly getting riper.”

Morgan has started nudging clients toward emerging regions, like the Uco Valley and Taurasi, in southern Italy. Wines of altitude are of particular interest to her, as are lesser-known varieties that thrive in the heat. Italy’s Aglianico grape, known as “the Barolo of the South,” likes elevations above 1,000 feet. It produces wines full of black fruit and tannin, a flavor profile that won’t be going out of style anytime soon. The Douro Valley, in Portugal, has a number of native red varieties that can withstand high temperatures. For white wine lovers who fear that a warming climate may endanger many white varieties, which tend to prefer cooler climes, Morgan recommends such Portuguese grapes as Arinto, which is able to retain acidity in severe heat.


Standing in the quiet of a vineyard in British Columbia’s Okanagan Valley, some 250 miles east of Vancouver, years ago, I felt as though the mountains rising in the distance could wake at any moment, like sleeping giants. Wine country was a different animal up there. Frost could give way to flurries; bears are as much of a pest as deer. The wines all seemed to possess a wild sagebrush quality that smelled of the desert itself. (The Okanagan, with its cacti and tarantulas, is home to Canada’s only true desert.) The wines were impressive to me then, in no small part because they were virtually undiscovered by the rest of the world. Perhaps even more impressive were the winemakers who helped pioneer the region. Philip McGahan left his native Australia because “he felt it was getting too hot,” says his boss, Anthony von Mandl, the owner of CheckMate Winery. McGahan could have gone to Napa or even Oregon. But he was looking farther—farther north and farther into the future of winemaking. He settled in the Okanagan, a place where he believed Chardonnay could be great.

In Burgundy, the average harvest date now arrives two weeks earlier than it did between 1951 and 2000.
Illustration: Laura Sant / Source: Southern Oregon University / Dr. Gregory V. Jones

A typically New World approach, you might say. The pioneering spirit is pushing the wine world as we know it toward the poles. The environmental scientist Greg Jones lists Nova Scotia, Sweden, and the Netherlands among emerging cool-climate wine regions. In the Southern Hemisphere, he names Rio Negro in Argentina, Central Otago in New Zealand, and Tasmania. Meanwhile, in the Old World, the only place to move is up, higher in elevation. The focus is on adapting rather than relocating.

Hubert de Boüard of Château Angelus, in Bordeaux, refuses to panic. And he remains unconvinced that rising temperatures are responsible for sweeter, more potent wines. Having grown up on the estate he now runs, he claims his wines are no more alcoholic than in his grandfather’s day thanks to vineyard management practices that protect grapes from excessive heat and sun exposure. He was not alive during the 19th-century phylloxera plague that devastated Europe’s vineyards, but at 65 he’s lived long enough to have witnessed its lingering effects.

“There are things we can’t control. But we must watch and listen to what nature is telling us,” he says. “Before phylloxera, there was a lot of Syrah growing in Bordeaux. The 18th-century wines of our region were different from what we have today. We cannot let ourselves be slaves to history. Man evolves and adapts. He must, in order to survive.”