Ana Puszkin-Chevlin, Ph.D., Regional Director, Growing Climate Solutions
Photo credit – Apolo Photographer via Unsplashed
With Naples Winter Wine Festival scheduled to take place this weekend and Valentine’s Day around the corner, we thought readers would be interested in how our changing climate is impacting vineyards and wineries, and how the industry is responding.
Wine grapes are among the most sensitive crops to variations in temperature and precipitation. The ‘terroir’, a term referring to the specificities of geographic place — the temperature, precipitation topography, soil — that gives a wine its characteristic taste and flavor, (and which also influences the wine style producers choose to make), is changing due to global warming. This has been driving winemakers to adapt their methods of growing and producing, applying climate science modeling to their century-old practices.
Simply speaking, warm climate wine regions, like the Mediterranean regions of southern France, Spain, Italy, and parts of California, allow grapes to ripen earlier and longer into the fall, producing fruitier, full-bodied wines with more sugar content, and thus slightly higher alcohol. The cool wine regions, those in Northern France, Germany, Cascadia, and New York’s Finger Lakes experience faster temperature declines in the autumn, preserving more tartness in the grape and resulting in crisper, light-bodied wines. Accordingly, winemakers plant grape varieties that are best suited to the climate of the specific geography and blend them to create the wine types unique to each terroir.
As global warming changed temperature and precipitation patterns, vineyards are beginning to reassess both the suitability – the varieties or types of grapes to grow – and the wine styles, that can be produced with consistent quality and yield. Foresighted growers study each microclimate, how latitude, elevation, and the surrounding topography, influence temperature and precipitation characteristics in order to match the variety to current and future environmental conditions. Grape varieties used to create premium wines, as opposed to “table” or “jug” wines are grown in regions where temperatures fluctuate less than 18 degrees from spring to fall, and for Pinot Noir, for example, the range is much smaller only about 4 degrees. Climate change can thus upend years of investment in grape cultivation or create new opportunities for varieties that were previously not suitable. In California for example, which accounts for 85% of domestic wine production, the average temperatures during the growing season have already increased 2.9 degrees since 1970. Thus, although Pinto Noir has been grown from as far south as the Russian River Valley in California, through Oregon and Washington State, in the coming decades, growers in the south may reconsider planting grapes suited for more robust and sweeter wines, while winemakers in Oregon and Washington may adjust the blends and production process to account for the changing flavor resulting from warmer seasons.
On a global scale, winegrowers in Champagne – the region of eastern France where the famous sparkling wine is produced – say warming temperatures mean they are having to harvest their grapes earlier. Some winemakers have started buying up land in southern England as insurance against climate variations that could change the distinctive flavor of Champagne. Likewise, the premium wine-growing areas of Chile, Argentina, South Africa, and New Zealand may shift southward and to higher elevations. Growers in Mendoza Argentina worry that warmer temperatures are also changing the phytochemicals that play a role in the color, if not taste, of its renowned Malbec grapes.
Drought has impacted the viability and yields in numerous wine regions, warmer and drier summers along with more limited irrigation reduce grape yields and the ability to cool the microclimate with misters during hot spells. As vineyards shift to higher elevations there may be land-use conflicts with conservationists protecting ecological resources and competition for water resources. Likewise, drought conditions fuel wildfires that have destroyed vineyards, winemaking facilities locally, and impact vineyards regionally as ‘notes’ of smoke and ash are never desirable wine flavors.
The art of winemaking depends on good science, and winegrowers have been applying climate modeling to its long-term planning, including planting appropriate varietals and purchasing land in regions where ideal temperatures may emerge in the latter part of the century. The Winkler Index, an index of regional climate conditions used worldwide to determine appropriate wine grape plantings since the early 1940s, is currently being updated by researchers at U.C. Davis to reflect climate warming trends. The Napa Valley, which was originally considered a region II and III within the Index’s five regions is now classified as III and IV. This may alter the desirability of planting Cabernet Sauvignon grapes, or at minimum make winemakers reconsider how to blend the grapes to retain the balance of fruit and earthy flavors for which their wine is recognized.
Climate change is unlikely to decimate the wine industry, but it will require proactive adaptation. As science can inform better decision making, the industry is now investing in climate research that helps clarify long-term decisions on vine planting, land acquisitions, technology for irrigation, and even marketing to influence consumers’ preferences for wines that are better suited to a warmer climate.
Resources: Climate change & Wine- https://medialibrary.climatecentral.org/resources/climate-change-wine
Climate Change Forces California Winemakers to reconsider What Grapes Grow Where –
https://www.winemag.com/2021/08/04/winkler-index-california-wine-climate/
Dr. Gregory Jones – TEDx – https://www.youtube.com/watch?v=aRwVFGjlOwU
Climate change, wine and conservation – https://www.pnas.org/content/110/17/6907.short