PARIS – Jean-Marc Touzard, an economist at the French National Institute for Agricultural Research, watched the climate change conference with interest and anticipation last week. He leads an interdisciplinary team in a wide-ranging venture to prepare France’s wine industry for the hotter, drier climate of the future.
Wine, closely tied to French cultural identity, is a leading export product, a magnet for tourism and a pillar of gastronomy. But grapes are highly sensitive to rising temperatures. A study in 2013 in the Proceedings of the National Academy of Sciences predicted that up to 85 percent of the vineyards in the European Mediterranean would become too warm and dry to grow grapes using current practices if climate change continued unabated.
A week before the conference concluded over the weekend, Touzard expressed concern in a crowded café near the Louvre. “French wines depend on these negotiations,” he said.
Among the provisions subsequently adopted by delegates to the meeting was a pledge to prevent the planet from heating up by more than 1.5 to 2 degrees Celsius above preindustrial temperatures. Experts warn that many political, economic and logistical obstacles may block achievement of this ambitious goal. But if the world does achieve the goal, Touzard will breathe easier. It would secure the future of French wine, he says, though vintners will have to change some practices if they expect to continue producing the high quality wines for which France is known.
In 2014, Touzard and social science colleagues conducted an experiment to help winemakers decide what course to follow as temperatures rise. The team served volunteers two different Bordeaux wines in glasses marked simply A and B.
One wine contained 13.5 percent alcohol, had “good acidity,” and “fresh fruit aromas.” It was “a current classical Bordeaux.” The other had more alcohol, 15 percent, low acidity and the aroma of “cooked fruit: figs and coconut.” This was what he calls “the wine of 2050,” the kind of wine he anticipates existing vineyards will produce within a few decades if they don’t adapt as the world keeps warming.
To the researchers’ surprise, the majority of subjects preferred the novel Bordeaux over the classic. At first the pollsters thought they had discovered that consumers could easily adjust to the evolution of wine, but they continued the tastings, day after day. By the end of the week many of the subjects had changed their minds. They preferred the classic Bordeaux after all.
“It was just a quick seduction,” said Touzard of the initial preference. “Disgust – perhaps that’s too radical, but we don’t want to drink more of this [new] wine. The flavors are too powerful.”
The sugar content of grapes tends to increase with temperature, which in turn produces more alcohol. In southern France, where Touzard lives, the average alcohol content of wine has increased from about 11.5 percent to 14 percent in only 20 to 30 years.
For centuries, French vintners have sought to raise the alcohol content of their wines by using the sweetest grapes. Now they’re are reversing course. Higher temperature destroys delicate molecules in the fruit, reducing acidity that gives wine its crisp, fresh taste. Warmer temperatures also alter flavor and aroma. Vineyards of southern France are now at the edge of climate suitability for the best wines, says Touzard. Territories farther north could face the same challenges in the next several decades.
Nevertheless, Touzard says that if global temperatures remain within the 1.5-to-2-degrees-above-preindustrial range written into the Paris agreement, vintners can continue producing traditional wines. They won’t have to move north, adopt novel processing techniques to modify flavors, remove alcohol, or plant new heat-adapted grape varietals from hotter regions in Spain, Portugal and Italy. Such changes would dramatically disrupt the country’s highly regulated wine industry, where grape varieties are associated with specific regions.
But regardless, winemakers will have to make some important changes. Touzard expects vineyards will be planted with more drought- and heat-tolerant hybrids of current grape varietals. They’ll employ inefficient, low-alcohol-producing yeasts. They’ll adopt new pruning techniques to take maximum advantage of leaf shade, and exploit the coolest microclimates in wine growing regions. With many incremental innovations, Touzard says, France’s centuries old wine industry should be able to adapt to the warmer world.