In early November 2019, more than 11,000 international scientists signed an SOS on behalf of our planet. The proclamation, titled “World Scientists’ Warning of a Climate Emergency” and published in the academic journal BioScience, made explicit connections between human activity and severe environmental repercussions. It also marked the first time such a vast and diverse pool of scientists rallied in support of as urgent a phrase as “climate emergency.”
Later that month, that publication was bolstered by a report from the World Meteorological Organization that claimed global greenhouse gas concentrations, and, specifically, those generated by human activity, had shattered new records. This is bad news, because those gases don’t just disappear: They stay in our atmosphere, trap extra heat near earth’s surface and cause global temperatures to rise.
If the earth continues along this trajectory, the United Nations posits that the planet is on course to experience a global mean temperature increase of nearly 5.76˚F between now and the end of this century. Given that thousands of years ago, when the thermostat dialed up just four degrees, it made enough of a difference to end the most recent ice age, this is a big deal.
What does this have to do with what’s in your glass? Well, a lot actually. Almost everything.
Wine is first and foremost an agricultural product. The grapes used to make it are grown and harvested with intent to be fermented.
This means that wine production is vulnerable to the effects of climate change from the tangible health of vines to the taste and quality of the finished bottling they create.
“Wine grapes are extremely sensitive to climate and this is much of what makes wine so exquisite. But it also means wine grapes are extremely sensitive to climate change,” says Elizabeth M. Wolkovich, associate professor of Forest & Conservation Sciences at the University of British Columbia in Vancouver, Canada.
Wolkovich studies how plants and plant communities respond to climatic shifts through phenology, the seasonal life cycle of a species. When it comes to grapes, she focuses on the Okanagan region of British Columbia and areas of California, but she often pulls together data from all over the world and collaborates extensively with colleagues in France.
“[Their] records are some of the longest written records on earth,” she says. “In Burgundy, records of harvest dates go back to the 1300s… For example, we can see that harvests recently are the earliest on record, meaning they are earlier than any harvest over the last 700 years.”
Though much of this data has been drawn from secondary sources, climate historians recently used original archives, cross-checked against other physical testimonies and regional temperature and environmental statistics, to compile 664 years’ worth of harvest dates and weather conditions surrounding the area of Beaune. Published in the European Geosciences Union journal Climate of the Past, it’s the longest known homogeneous series of grape harvest dates available, and it shows that temperatures have climbed so much, harvests now begin an average of 13 days earlier than they did prior to 1988.
“[They] have already altered the phenology each season and sugar to acid ratios in berries,” says Wolkovich. In warmer conditions, she says, grapes ripen quicker and more easily, which lowers their acidity and increases their sugar. If picked at the right time, resulting wines are fuller, softer and fruitier, with higher levels of alcohol.
Temperatures have climbed so much, harvests now begin an average of 13 days earlier than they did prior to 1988.
These aren’t necessarily undesirable traits, especially in places where grape cultivation is trickier in the face of cool temperatures.
“Warming does have the ability to create a situation in which some varieties may actually do better,” says Gregory Jones, director of the Evenstad Center for Wine Education and a professor and research climatologist in the Department of Environmental Studies at Linfield College in Oregon. “If you’re growing a cool-climate variety in too-cool conditions and it suddenly warms a little bit, you’re going to get more consistency, and more consistently good vintages,” he says.
It’s a hot streak, as it were, that’s already been observed. For instance, winemakers in Bordeaux and Burgundy expressed much excitement for the warm 2019 vintage soon after harvest. Bottlings produced throughout portions of Italy in recent, warmer years have yielded more delicious and consistent results.
Germany, home to some of the northernmost wine regions, is one place that’s more or less lucked out across the board, having achieved excellent vintages in the heat of recent years. Vines that once struggled to ripen have begun yielding plump, juicy grapes and incredible dry bottlings. In warmer areas like Baden, wines are becoming more velvety and full with every degree uptick.
“With every vintage, we learn new things from nature and react individual to given situations… [this year] in our case was good for both quality of the grapes and concentration of the wines,” says Yquem Viehhauser, of Baden’s Weingut Bernhard Huber.
Warming has also caused the boundaries of viable growing area to swell. Typically, successful vineyards have been found between 30 and 50 degrees latitude. But as global average temperatures continue to climb, the most ideal areas to plant are moving farther from the equator.
Now, areas as far up as the island of Föhr and Stargarder Land in Mecklenburg, at the tip-top of Germany, are legally permitted to produce table wines. Belgium, whose vinous history has been overshadowed by its beer culture, quadrupled production between 2006 and 2018; it’s forecasted to become a champion, alongside Finland, Sweden and other boreal climes.
England has also successfully entered the modern fine wine scene.
“I was astonished that you could create wines with such quality, energy and flavors in England,” says Adrian Pike, managing director and winemaker at Westwell Wine Estates in Kent, England.
Westwell was established by John Rowe in 2008. Pike and the vineyard manager, Marcus Goodwin, took over just before the 2017 harvest, and began reducing chemical intervention and reinvigorating the vines. Though they have only three vintages at the estate under their belt so far, he says things keep getting better.
“In general, the quality of the fruit in all three years has been fantastic, although 2018 was exceptional,” he says. “Despite all of our hard work, the main criteria for the variants in yield has been the good old British weather, especially the timing of rainfall.”
With better wine from regions we know and new wine from previously uncharted areas, it may appear the wine world is becoming better off. In truth, however, this is a thin silver lining to ever-worsening viticultural challenges.
Back in France, feedback about the conditions surrounding Champagne’s 2019 harvest was chock-full of praise. Yet, at Champagne Lelarge-Pugeot in Vrigny, seventh-generation vigneron Dominique Lelarge says overall, the season was far from ideal, and that conditions throughout the past few years have been a mixed bag.
“The weather pattern changes but the last couple years has been consistently more sun, more tropical rainstorms, but less water throughout the summer. This year, we had multiple heatwaves and … the vines struggled,” he says. “We harvest earlier and earlier. My grandparents harvested mid-October and now we harvest the second week of September… The juice is warm, as it’s hotter during harvest, which is not ideal, and now, because it’s warmer, our base wines are fruitier and richer.”
“Because it’s warmer, our base wines are fruitier and richer.” –Dominique Lelarge, vigneron, Champagne Lelarge-Pugeot
On a timeline of forecasted climactic shifts, Lelarge and his grapes are in limbo. If temperatures continue to rise as projected, his fruit may see more significant changes. Even for varieties that benefit from warmer conditions, research contends there is a point at which things begin to sour.
If the growing season becomes too hot, fruit will push through its life cycle too quickly and characteristics like tannins and anthocyanins, the compounds responsible for giving grape skins their color, won’t develop properly. Muted acid and increased alcohol levels are also possible and often undesirable.
Variations between daytime and nighttime temperatures are in jeopardy as well. In warmer growing regions, that difference can be crucial to achieving freshness and encouraging certain flavor and aroma development.
Intense heat or too much direct sunlight can lead to dried fruit notes or create flabby and dull wines. Fruit that’s left too long on the vine can be damaged from sunburn or may simply shrivel. Vines may just shut down to protect themselves.
This is already happening in some places. Wine growers in northern Italy have already seen sunburnt crops with increasing frequency. The summer of 2019 in Southern Australia was the hottest since national records began in 1910, and it ushered in an 8% loss of white wine varieties, with Chardonnay dropping 12% to its lowest yield in the past five years. Growers in Priorat, Spain, reported devastating vine damage, scorched leaves and desiccated grapes when temperatures shot up to a record 107.6˚F.
Climate change is complicated, however, and, even though “temperature is the most influential factor in overall growth and productivity of wine grapes,” according to Jones, there’s more than rising mercury to think about.
“Heat accumulations and things are really important in terms of how they influence just the broader perspective,” says Jones, “but there’s lots of other things going on within the framework of what climate really does to growing grapes.”
Winter, and all of its prescriptions, is one of those “other” things. “We typically talk about warming, yet, freezes during the winter or extreme frost in the spring don’t go away. They may become less frequent, but potentially more severe.”
A decrease in regular winter frosts may also encourage the spread of pests and insect-borne diseases that would normally die off during cold seasons.
Moisture is pivotal. Too much rain approaching or during harvest can lead to watery grapes and a weak vintage. Similar to mild winters, damp, soggy and humid conditions open the door to a variety of pests, fungi, mildew and disease pressures.
Rising sea levels, which, according to NASA, are estimated to surge at least 26 inches by 2100, have the capability to destroy or alter coastlines and their sway over nearby viticultural climes.
Severe floods are also possible and could leave swaths of vineyards in Portugal, New Zealand, California and other regions completely underwater.
More inland areas, meanwhile, become more prone to groundwater salinization. This and drought can be a giant problem.
Vines may be more tolerant to water deficiency than other crops, and the stress can even be desirable, spurring root growth as they seek a water source below. But too much stress can hinder photosynthesis, delay or inhibit bud ripening, lower winter hardiness or cause the vine to stop producing altogether.
In such periods of water scarcity, soil, too, is under serious threat of erosion and desertification.
While irrigation can help somewhat, it may not always be possible.
This recently played out in South Africa, which is still feeling the effects of a three-year drought. The organization Vinpro, a nonprofit company that represents the country’s viticultural interest, reports a decline in vineyard area, improper berry set, hindered vine growth overall and the smallest yield since 2005.
“In the future, I expect growers to struggle with maintaining varieties in certain regions.” –Elizabeth M. Wolkovich, associate professor, University of British Columbia
All of these intricacies and others work in conjunction with temperature to dictate what vines can successfully grow where and for how long—and all are increasingly unpredictable or totally upended in the face of climate change.
The people who grow, make and sell wine are tuned in to these nuances.
“At least for wine-grape growers, most I know agree things are changing,” says Wolkovich. Many are applying strategies to adapt to or mitigate the shifts.
Some growers are pursuing higher altitude sites, which evidence suggests offer shorter periods of intense heat or are better at sustaining day-night temperature swings. Spanish producers headed to the peaks of Priorat, Rioja and Ribera del Duero years ago. Washington State winemakers, who previously needed lower elevations to encourage ripening, have now been looking up in order to retain natural acidity.
Others, like a crop of Chilean winemakers who recently took on Patagonia, are blazing into wild territory where nothing is guaranteed. Their hope is that the patchwork of microclimates and terroirs will provide future reprieve from some of nature’s elements, even if it means risk in the present.
A greater number of producers are rethinking canopy management, vine trellising or pruning techniques, developing cover crops and extensive shading methods, increasing vineyard biodiversity and finding ways to reuse water.
Still, there are some challenges that cannot be overcome.
“In the future, I expect growers to struggle with maintaining varieties in certain regions without major interventions,” says Wolkovich. “If they don’t make major changes, I think they will see declining yields—already seen in Europe—and declining quality as the varieties become increasingly mismatched to the climate.”
Producers have begun grafting new rootstocks and experimenting with different grapes. In South Africa, Vinpro, aided tests of drought-resistant varieties including Assyrtico and Marselan, for example. Australian producers have tried Italian grapes like Fiano, Vermentino and Nero d’Avola that thrive in warmer settings.
Winemaker Dan Petroski at Larkmead in Calistoga, California, and his team are at the forefront of experimentation with new varieties in Napa Valley.
“Technology will assist, farming practices will assist, but there is no silver bullet when the temperatures climb in prolonged heat events where they’re above 100˚F for a week or two weeks or so forth,” says Petroski. “In 2017, we had 28 days out of 100 growing days over 100˚. We had 11 days over 110˚, three above 115˚. There’s nothing you can do in the vineyard…that’s going to help the vines to process when it gets that hot for that period of time. You have to work with varieties that mature under those conditions.”
He’s experimenting with heat-loving grapes like Aglianico, Touriga Nacional, Tempranillo, Shiraz and others.
“Cabernet Sauvignon may no longer be relevant in Napa Valley in 2040, ’50, ’60, ’70,” he says. “We’re planting these today so we can evaluate over the course of time if this is relevant to our neighborhood.”
In Old World regions, where grapes and blends may be prescribed by law, the idea of swapping plantings is monumental.
Bordeaux is one such place, and, at a 2019 General Assembly meeting, it finally relented. The Union of Bordeaux AOC and Bordeaux Supérieur winemakers unanimously approved a list of seven “varieties of interest for adapting to climate change”: Arinarnoa, Castets, Marselan, Touriga Nacional, Alvarinho, Liliorila and Petit Manseng.
The approval of these new plantings signals just how committed the region is to preserving the future of fine wine.
Each of the various tactics being implemented worldwide take lots of time, tests and research. Petroski calls Larkmead’s grape experimentation a “21-year plan” because of how long it takes to plant vines, grow grapes, and then create and age a wine; finding sustainable farming practices for a plot takes trial and error.
Further, the methods being devised now may not be applicable down the road. Though there are several models in use to try and predict changes, they are attempting to track a nonlinear problem that’s dependent on a range of forthcoming scenarios.
Basically, the only thing we do know for certain is that it will get warmer, and that we may be able to anticipate that heat before it hits us.
“The thing that I think is really problematic is the variability that we’ve been seeing in climate,” says Jones. “Having average changes is one thing, but having more and greater extremes, for example, sudden heat stress over [95˚F] can really be very damaging. As we’re moving into warmer climates, all of our projections say were likely to see more of those events.”
It’s these sorts of conditions that trigger disastrous weather events like droughts, floods and unforeseen storms. And indeed, “hail and fire also appear to be increasing in some important regions,” says Wolkovich.
There are several models in use to try and predict changes, but they are attempting to track a nonlinear problem.
However it does play out, “it’s going to change everything,” says Petroski. “We have to be asking what we can do now to preserve the integrity of the grapes and vineyards we work with and look for where our opportunities are to continue making wine.”
For the time being, members of the wine industry seem to agree that one path is clear.
“No matter what part of the industry you’re in, you need to reduce your carbon footprint— period,” says Michelle Bouffard, founder of the Tasting Climate Change conference in Montreal. “Everyone’s needs are different, and it really depends on the region. The one line that works for everyone is to cut carbon emissions, that is the emergency action that needs to be taken.”
She points to leaders like Miguel Torres for driving actions by example. He’s the president of Spain-based Familia Torres, which has dedicated more than 12 million euros to lowering the company’s emissions and has been able to reduce its carbon footprint more than 27%.
In partnership with California’s Jackson Family Wines, he formed International Wineries for Climate Action (IWCA), a global collaborative of wineries that has committed to strict carbon reductions and focuses on science-based, sustainable solutions, in 2019. While it’s widely acknowledged that actions will need to happen across both regional and sweeping industry levels, IWCA, along with expansive platforms like The Porto Protocol, a sustainability project with the goal of sharing objective solutions, help spread awareness and open channels of communciation.
“This is a global initiative. We’re all starting to see this and we’re all affected,” Petroski says. “We know we can’t turn it backwards, and we’re not even sure we can slow it down. But we have to try.”
Last Updated: May 8, 2023
