IMAGINE a world in which the best sparkling wines come from Surrey in southern England, not Champagne. A world where Monterey Bay is home to California's best Cabernet Sauvignons and Sweden produces world-class Rieslings.
It's not science fiction. A growing number of climatologists are warning that by the turn of the next century, such a radically altered wine map could be the new reality. They say man-made greenhouse gases warming the planet are expected to shift viticultural regions toward the poles, cooler coastal zones and higher elevations.
Burgundian Syrahs? Quite likely. Scientists say that, in 50 years, Napa could be as hot as the Central Valley's Lodi appellation is now. Bordeaux is on track to have a climate similar to France's southern Languedoc region. Germany, on the other hand, will be producing luscious red wines.
"I don't think you can make a vineyard decision today based on historical information," says David Graves, one of the owners of Napa Valley's Saintsbury wines. "You have to factor in climate change."
As he paces the floor at his Carneros winery, Graves explains that vintners plant and tend their vineyards with an eye to a 50-year horizon. Now the future seems unknowable, he says.
Wine is the canary in the climate-change coal mine, according to climatologists. Even slight changes in climate can wreak havoc on high-quality wine, making it particularly vulnerable to global warming.
In young, dynamic wine regions like California, where the weather is currently considered optimal, it is difficult to track global warming's effects. So many things are constantly changing. But the research suggests that such regions may be at the edge of what is ideal. Slight climate changes could be enough to push them over that edge.
Meanwhile, in European wine regions that have struggled to ripen grapes for centuries, global warming is a cause for celebration. Each year in the last decade seems to have brought another "vintage of the century."
No question, says London-based wine critic Jancis Robinson, global warming is changing wines. "Dry German wines now are seriously delicious. English wines and Canadian wines have benefited." On the other hand, she says, wines from warmer regions including Spain and Australia are suffering the rise in temperature.
"With wine, we can taste climate change," says Gregory V. Jones, a climatologist at Southern Oregon University who is a leading researcher in the burgeoning field of wine-region climate studies and the son of an Oregon vintner. "You can honestly argue that Bordeaux is better off today. They can now consistently ripen their grapes."
The year 2005 was the warmest recorded in the United States in the 150 years that good records have been maintained. And each of the last nine years has been among the 25 warmest on record in the U.S. Globally, each of the last 15 years has been in the top 25 hottest years on record.
The acute environmental sensitivity of wine grapes separates vineyards from other agricultural systems, says Dan Cayan, a climate researcher at Scripps Institution of Oceanography. "If you believe the viticulturists and their classifications of where premium wine can, and cannot, be produced, and you impose the global warming projections," he says, "you find some areas would possibly be thrust into a climate no longer suited to the grapes now grown there."
THE wine world is scrambling to guard against disaster. In a stunning bow to climate change, French wine regulators last month approved the use of vineyard irrigation, reversing centuries of tradition to rescue regions suddenly too hot for dry farming.
UC Davis scientists are breeding new strains of vines and root stocks that can better survive extremes of heat and drought. Spanish vintners are studying whether they can plant vineyards in the cooler foothills of the Pyrenees. Belgium, Denmark and even Sweden are jumping into viticulture.
The changes in traditional viticulture challenge the cherished French notion of terroir -- the predictable expression of soils, climate and traditions in the grapes identified with a particular place -- ushering in a new era in wine.
"The research is clearly pointing to major long-term risks to an industry that people in California care about," says Chris Field, director of the Carnegie Institution, Department of Global Ecology at Stanford University. The question facing the wine industry, Field says, is whether it will be a victim of global warming or "are they going to assume a leadership role to ensure that their way of life is sustainable?"
It's a sensitive issue on which Robert P. Koch, president and chief executive of the Wine Institute, the industry's chief Washington lobbyist, has kept a low profile. Careful not to get out in front of his brother-in-law, President Bush, or the conservative wine industry, Koch says the Wine Institute's board is starting to discuss its options.
President Bush declined in 2005 to sign the Kyoto Protocol, a United Nations agreement to reduce greenhouse gas emissions that contribute to global warming, signed by 169 other governments including the developed nations of the world with the exception of Australia. Other politicians deny the existence of global warming, Koch says, mentioning Sen. James M. Inhofe (R.-Okla.), former chairman of the Senate's Committee on Environment and Public Works, who calls it a "hoax."
When pressed, Koch distances himself from both Bush and Inhofe. "Grabbed in an aggressive manner, global warming is a challenge that can be solved," he says. Whether they like it or not, Koch says, California vintners "recognize that we [the Wine Institute] are on the cutting edge of this global environmental issue."
In France, the projected climate changes threaten the very definition of wine, says Bernard Seguin, a climatologist with the French National Agronomy Institute. Each one degree increase in temperature in France is equivalent to moving 200 kilometers (or 124 miles) north, he says. By the end of the century, with current warming predictions, the north coast of France will be experiencing weather that today is common for the south of France. Burgundy will feel like the Cotes du Rhone, he says, and Bordeaux will make wines that resemble those the Languedoc produces today.
Up to this point, global warming has been a boon for France, Seguin says. Rising temperatures have produced wines with higher sugars and alcohol levels and lower acids that are very popular.
"Our weather now is perfect," says Jean-Guillaume Prats, the renowned chief executive of Chateau Cos d'Estournel, a second-growth Bordeaux house in St. Estephe. "Global warming has changed the style of wine we make to be a rounder, a more forward wine."
BUT what happens if Bordeaux becomes too warm?
That is not possible, Prats says. "We are Bordeaux." The region is protected by its proximity to the Atlantic Ocean, he says. Any further changes in temperature can be managed by technology and, perhaps, a little irrigation, he says. "We will learn from California."
Michel Chapoutier, a celebrated Hermitage producer in the northern Rhone, disagrees. Global warming may be making his wines more popular, but he believes it has come at a price.
Traditionally, the grapes in his vineyards could be harvested with the sugars and other flavors ripening simultaneously, he says, with alcohol levels averaging 12%. Today, he says, the sugars arrive too quickly, before the other flavors. Chapoutier says he must leave his grapes hanging longer on the vine waiting for full ripeness, which results in alcohol levels averaging 14%. To a California vintner, this might seem acceptable, but to Chapoutier, it is evidence of a buildup of greenhouse gases in the air and a warming climate.
"I'm nervous about the future," Chapoutier says. "Yes, we have more and more good vintages now, but we have to choose between vegetal wines or ones that taste like jam."
"The old system of wine production in Europe, the notion of terroir, is now questionable," Seguin says. "We must either do things to make the old system adapt to the new climate, striving to keep the classical qualities of wine by making changes in how we manage vineyards and make wine. Or, we must become like the New World, changing the vineyards to grow whatever grape variety is right for that climate and planting vineyards in new places."
The heat wave in Europe in 2003 sounded the alarm, Seguin says, becoming the example of the future. "Those are very different wines. Not bad wines, but very different," he says. "It made it possible to move from thinking about global warming to doing something about it."
And California? Jones' research shows that 50 years ago, the Central Valley's Lodi region had temperatures on par with what Napa experiences today. If current warming trends continue, in another 50 years Napa's climate could be as hot as Lodi's is today. And the Central Valley could be too hot to grow any kind of wine grapes. In 2049, the regions most suitable for high-quality wine production, according to Jones, may dot a narrow strip of the coast.
Noah Diffenbaugh, a climate scientist at Purdue Climate Change Research Center, projects that by the end of the century, human-driven climate warming could reduce the areas suitable for wine production in the U.S. by 81%. Within those territories, optimal regions for producing the highest quality wines would be half what they are today.
Diffenbaugh anticipates an increase in the frequency of heat spikes. Extremely hot days (95 degrees Fahrenheit or higher) in California's existing wine regions could occur between 30 to 50 times more often each year by the end of this century. Research into increased heat spikes in Europe's wine regions, he says, indicates a similar increase in the number of extremely hot days.
Not everyone is buying the doom and gloom. Some of Graves' Napa neighbors believe that scientists are exaggerating the risks. Napa's geography, they say, protects it from climate change. And Sonoma's proximity to the coast will keep it cool. That's assuming, of course, the oceans are immune from warming.
"I don't think anyone is trying to deny global warming," says Jim Verhey, a director and manager of Silverado WineGrowers, which owns 200,000 acres in Napa Valley, Sonoma, Monterey and Lodi. "But we believe that the marine influence from the San Francisco Bay mediates the effects on Napa Valley. We believe we haven't seen changes in Napa's temperatures."
It is tempting to speculate that the increasingly higher alcohol levels of California wines are the result of a warming climate. But, according to Jones and other scientists who have studied the relationship of global warming and wine, that's difficult to prove.
California vintners have altered their viticulture practices during the last two decades, increasing the time that grapes hang on the vine. This increased exposure of the fruit to the sun has raised sugar levels, which raises alcohol levels. How much of the higher alcohol levels are due to longer hang time, and how much to rising temperatures? It is impossible to know, they say.
"Our parameters for ripeness have changed," says Paul Hobbs, a winemaker well-known for his ripe, powerful wines. He no longer even tests for sugar levels, he says. By concentrating instead on the phenolic development, referring to the other grape flavors, he finds himself among the last to harvest in Napa. "I farm completely differently than I did 17 years ago," he says. "I can't see any effects from global warming on my grapes."
While Hobbs does believe the global climate is changing, he doesn't believe that, on average, Napa is warmer. Still, "I've seen more heat spikes, absolutely. If that is an indication of global warming, then yes, even in cool vintages we have them," he says.
Jones studied viticultural climate data from 1948 to 2004 and found an increase in average growing-season temperatures worldwide of 2.3 degrees. Night temperatures warmed more dramatically than day temperatures, reducing the swing between high and low temperatures that is desirable for producing high-quality wine.
Longer growing seasons
WORLDWIDE, he found higher temperatures during ripening, less frost, and longer growing seasons (from 20 to 40 days longer in Europe, up to 90 days longer in Napa Valley). Southern Hemisphere climate changes were less pronounced than in the Northern Hemisphere, due to the moderating effect of the higher ratio of ocean to land mass.
Jones believes those trends will continue during the next 50 years with worldwide average growing-season temperatures increasing an additional 2 to 3.5 degrees. Greater warming is projected for southern France, parts of eastern Washington and Central California. Temperatures in Spain and Portugal could increase more than 5 degrees, he says, which would make all but the high-altitude viticulture extremely difficult.
Those projections have set off alarms in Spain, says Pancho Campo, president of the Wine Academy of Spain. He organized the first World Conference on Global Warming and Wine last March in Barcelona, attended by more than 100 scientists, journalists, and winemakers. A second conference is set for February 2008. "In Napa, it appears that a lot of very rich people may have sunk a lot of money in the wrong place. We're suffering the same thing here in Spain," Campo says. "We had to drag the growers and vintners in to addressing global warming. Now, six months after the conference, it's unbelievable how attitudes have changed."
Miguel Torres, one of Spain's leading vintners, made headlines when he announced he was mapping soils of the lower slopes of the Pyrenees, 25 miles closer to the mountains than where his vineyards now are planted. "Last year was the hottest vintage in the history of the Spanish wine industry," Campo says. "Everyone is very concerned. It's starting to touch their pockets."
Hans-Rainer Schultz, a climatologist at Germany's Geisenheim Institute whose studies corroborate Jones' predictions, says it is difficult to motivate people to be concerned about change when, so far, it has been beneficial. "The coolest climates are feeling the effects first -- France, Germany, Austria -- and it's been positive," he says. How else can you explain lush red wines from Austria?
"In the Mosel Valley, growers were allowed to add water to the wines until the early 1980s to reduce acidity. They could add sugar as well. It was very controversial when they stopped those practices because our wines needed those additives to be competitive, to be consistent," Schultz says.
"Today, no one would want to add these things," he says. "We have trouble maintaining our acids. It is no longer difficult to get the sugar content up. In fact, we worry that our alcohol levels are too high. We haven't had a bad vintage since 1987, and the reason is global warming."
Now, Schultz says, "everyone is happy with the changes. It used to be that 4 or 5 vintages out of 10 were marginal. It's why we made sweet wines, to mask the sharp acidity. Now we have less problems."
There is growing concern, however, that Germany may be getting too warm. "Riesling, in a warm climate, you get the kerosene, petroleum character. That's not what consumers are looking for in young, dry Rieslings. Now we get that character very fast, instead of after two or three years of age in the bottle," Schultz says.
So, like David Graves in Napa Valley, German vintners are struggling with questions. Should they plant the grapes that their fathers and grandfathers did, or is it time to look south for guidance?
Riesling, Pinot Gris and Pinot Noir have always been suitable for Germany. But in 20 to 50 years, Schultz's research indicates that Merlot and Cabernet Franc may be more appropriate.