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.