Wine Regions Feel the Heat
by: Elizabeth Weise 2 June 2006
In another 50 or so years, the world may be a much different place for wine aficionados, courtesy of global warming.
Famed wine-producing areas such as California's Napa Valley and France's Burgundy region may relinquish their supremacy to other lands, experts say, as higher temperatures redefine wine country.
Because wine grapes are so temperature-sensitive, even tiny changes can be the difference between a $200 Cabernet Sauvignon and cooking sherry. Warming is already having major effects on wines, with more to come.
In the short term, warmer temperatures have made for happier vintners, at least in Europe. In France, the last 10 years have produced a series of excellent vintages, especially in Champagne and Bordeaux. Germany's Rhine and Mosel valleys are now producing some of the best wines they've ever made, says Richard Smart, an internationally known viticulture consultant based in Tasmania.
England has seen a renaissance of the wine-growing culture that died out in 1300, when the Medieval Warm Period ended. Today, England and Wales, with late-spring freezes banished and long, warm summers the rule, are home to more than 400 wineries.
But don't pop any corks yet. Wine grapes are generally grown in a narrow band of land with average temperatures between 50 and 68 degrees. If it gets much hotter, many world-class wine regions, including southern France and the Napa Valley, may be either at or nearing their optimum climates for the varieties now grown there, say Gregory Jones, a climatologist who specializes in viticulture at Southern Oregon University in Ashland.
A paper published in The Proceedings of the National Academy of Sciences found that if climate change proceeds as expected, by 2100 the viable grape-growing regions in the world will be reduced by nearly 80%.
In Napa, the minimum temperature has gone up nearly 5 degrees over the past 75 years, while the growing season has increased by more than 50 days, according to Jones' research.
The grapes often ripen in August rather than September, when it's hot enough for spontaneous fermentation, Jones says. "People are having to harvest their fruit in the middle of the night to get their fruit in when it's cool," he says.
To Jones' mind, the Napa Valley is already a little too hot to grow great grapes. He says if it had never been planted in grapes and people asked him now if they should start a vineyard there, he'd say, "Don't do it."
But if Napa's out, other North American regions may take its place, Jones says, such as: British Columbia's Okanagan valley, Washington's Puget Sound area, upstate New York and Long Island, Michigan's coastal zone and Virginia.