The long fingers of climate change have begun to disrupt our lives in ways we may never have expected. In a recent paper published in the journal Nature Climate Change, two scientists say we can expect a disruption in the world’s wine supply in the near future.
Wine grapes are fussy little things, requiring just the right soil composition, sunlight, moisture, and temperature. When wine grapes don’t get what they want, wine quality suffers. Each factor on its own changes the grapes.
For this study, ecologist Elizabeth Wolkovich and climate scientist Benjamin Cook wanted to get a big-picture view of how drought and temperature affect grape harvests and wine quality. They analyzed climate records from the 20th and 21st centuries, as well as earlier records of temperature, precipitation, and soil conditions. They also consulted more than 500 years of vineyard records from France and Switzerland.
In general, the higher the temperature, the faster the grapes ripen and the earlier the harvest. Historically, this has been tied to seasonal droughts (especially in France and Switzerland). As the ground dries out, it heats up, pushing the temperatures high enough to ripen the grapes. Without the drought, there’d be no burst of heat, meaning no early harvest.
The scientists found that this drought-temperature-harvest dynamic held true, but only until the 1980s, when global warming really started to turn up the heat. Over the 20th century, average temperatures in France rose by 2.7°F, and the mercury continues to climb. Sure, 2.7°F might not sound like much to you, but ask a fussy grape how it feels.
"Now, it's become so warm thanks to climate change, grape growers don't need drought to get these very warm temperatures," Cook said in a press statement. "After 1980, the drought signal effectively disappears. That means there's been a fundamental shift in the large-scale climate under which other, local factors operate."
The researchers say the shift in dynamics is most pronounced in regions like Alsace, Champagne, Burgundy, and Languedoc; all are regions that grow Pinot Noirs, Chardonnays, and other relatively cool-weather varieties that are especially sensitive to changes in temperature.
While more heat may seem like a good thing, the grapes can only take so much. The authors say that, for right now, the bump in temperature has actually been pretty good for the grapes. "So far, a good year is a hot year," Wolkovich said in the press release. But there’s a limit to how much the grapes can take. "If we keep pushing the heat up, vineyards can't maintain that forever."
This means that, in time, these regions will no longer be able to produce these types of wines. "If people are willing to drink Italian varieties grown in France and Pinot Noir from Germany, maybe we can adapt," Wolkovich said. It's a big "maybe," though, as it's unknown whether or not the grapes themselves will be able to adapt to these totally new environments.