Winemakers Facing Climate Change: Adaptations

While just a few years ago some winemakers remained skeptical about global warming, today the entire industry has become aware of the phenomenon, and climate change is now on everyone’s mind—in vineyards and in agriculture in general.

Global Warming in Vineyards

Climate change, global warming, adaptation… all these terms are popping up in reports, conferences, working groups, and seminars, and the entire industry—from winemakers to institutions—is now aware of the problem. It is impossible to ignore it after the extreme weather events of recent years, which have destroyed several harvests and significantly altered the intrinsic characteristics of the wines. Early harvests, high alcohol levels, a notable decrease in acidity, floods, thunderstorms, hail, spring frosts, and droughts have marked the last three vintages.

Reducing excessive heat on grape clusters

When temperatures are too high, ripening comes to a standstill. Winemakers are therefore increasingly focusing their efforts on individual vines to lower the temperature of the berries. In the south of France, growers reduce or even stop leaf removal to protect the grapes from the sun using the foliage. In Burgundy, where humidity is high, winemakers prefer to increase the height of the pruning (an operation that involves trimming the tips of the shoots).

“Global warming doesn’t mean good weather,” points out Ludivine Griveau, estate manager at the Hospices de Beaune in Burgundy, in an interview with Bourgogne Aujourd’hui. Indeed, Burgundy is facing higher temperatures coupled with high humidity, which is effectively increasing the risk of pest infestations.

Combating Droughts

Water availability will be the major challenge in the coming years, a stark consequence of climate change. Rainfall events are more intense and less evenly distributed throughout the year. They often cause damage and prove insufficient in the face of summer droughts. Winemakers are reviving farming techniques that help improve soil drainage, limit erosion, and replenish groundwater reserves.

Grass cover in vineyards is a topic that is increasingly being studied in research centers and adopted by winegrowers. Grass cover helps enhance biodiversity, protect the soil, and maintain moisture levels around the vine roots. In the Languedoc, where summers are extremely dry, weeding between rows prevents weeds from competing with the vines for water.

Toward Irrigation of Vineyards?

The issue of irrigation is indeed becoming increasingly prominent in vineyards. Will it one day become essential for continuing the production of quality wines? Or will water constraints render this solution obsolete before it even becomes a serious topic of debate? Looking beyond our borders, it is clear that while irrigation has helped the development of vineyards in the provinces of Mendoza (Argentina) and California (United States), it does not solve the wine industry’s problem of global warming in these regions, nor does it provide a solution to water scarcity.

Adaptation through the selection of grape varieties

Fully aware of this contradiction, the IFV (French Institute of Vine and Wine) is focusing its research on varietal improvement and rootstock selection in order to offer growers varieties with greater water resistance. In fact, winegrowers did not wait for the results of this research to begin adapting the varieties on their plots, favoring more water-efficient grape varieties that can adapt to rising temperatures.

Limiting the alcohol content of wines

Recent vintages bear this out: alcohol levels are rising, acidity is falling, and it is not easy for winemakers to maintain a good balance. A glance at winemaking product catalogs confirms the trend. Yeasts that limit alcohol production and/or increase acidity in wines are increasingly being offered as a solution to winemakers. Winemakers are also adjusting maceration times to balance the wines, making slight but fairly easy modifications to winemaking processes, as Ludivine Griveau explains: “A slightly longer maceration before red fermentation begins, to extract the maximum amount of aromas […] Followed by a shorter alcoholic fermentation, allowing the alcohol to develop more gently, resulting in silkier tannins.”

Global Warming: A Boon for Northern Vineyards?

It’s a refrain we sometimes hear: vineyards are moving northward, a boon for some regions at the expense of those in the south. Professor Monika Christmann, director of the University of Geisenheim in Germany, reports, however, that global warming—which was initially beneficial for Germany’s vineyards—is “now proving to be too severe.” Furthermore, “while summers are becoming increasingly favorable for wines, they are also becoming increasingly chaotic, and winemakers must contend with extreme weather events.”