Imagine this: Many of California’s prime wine regions are gone, with desert having reclaimed much of the state’s landscape. Bordeaux’s wine production is way down, with cabernet sauvignon and merlot giving way to grenache and mourvèdre in red blends. Wine production in Australia has fallen by three-quarters, in South Africa by more than half, and in Chile by two-fifths. Riesling vines have disappeared from many of Germany’s vineyards. New, prestigious regions have emerged in northern Europe, in countries such as Denmark and Poland, and England has become a wine producer to be reckoned with. Ontario and British Columbia are now known for their full-bo-died reds, while southern Quebec is thought of as a new Burgundy.
These are some of the scenarios suggested by studies of the effects of climate change on wine production over the next few decades. Although they’re vigorously debated in the wine world—they’re based on assumptions of specific temperature increases that may or may not occur—they of course haven’t figured prominently in public discussions of climate change. Which varieties will be used in Bordeaux blends in 50 years is hardly as important as rising sea levels, shrinking polar ice caps, and increasingly frequent and devastating hurricanes, floods, and forest fires.
Yet viticulture (grape growing) is an integral part of the agricultural landscape, and climate change raises questions about it. How does climate change affect viticulture now, and what will its impact be as the century unfolds? What can producers do to counter the effects of climate change, and how will they deal with what they can’t mitigate? What will climate change mean for wine consumers?
In Australia’s Yarra Valley, the harvest that 50 years ago began in early April now starts in early March and sometimes even in February.
There’s no doubt that climate change is already having an impact on wine. For one thing, rising temperatures generally mean that grapes ripen sooner, and in many wine regions early harvests have become the rule. In Alsace and Bordeaux, harvests typically take place two weeks earlier than they did in the 1980s. In Australia’s Yarra Valley, the harvest that 50 years ago began in early April now starts in early March and sometimes even in February. In itself, an earlier harvest is not problematic, but all phases of grape growth are affected by rising temperatures. When flowering occurs earlier, there is greater risk of frost damage. When grapes ripen closer to the summer, rather than in the cooler autumn, they tend to have higher sugar levels and less acidity, producing wines with higher alcohol and more intense flavours, but less of the freshness that acidity contributes.
Over the long term, temperature increases change the character of growing regions. Those now planted in hardy hybrid varieties will become suitable for Vitis vinifera (the most common grape variety used for wine). It’s estimated that producers in southern Quebec, now largely dependent on hybrids, will be able to grow chardonnay and pinot noir easily by mid-century. In a knock-on effect, cool climate regions will edge toward warm, and warm regions will become even warmer. Regions that are already very warm, such as Lodi in California’s Central Valley, will become marginal for viticulture or unable to sustain it at all.
At the same time, some regions that are currently too cold for viticulture will become vine-friendly. One study predicts that between 2020 and 2050, the northern limits of vine cultivation in Europe will advance 20 to 60 kilometres each decade. In Canada’s main wine regions, vineyards are being planted farther north than ever before: the newest official wine regions in British Columbia include the province’s most northerly—Lillooet, Shuswap, and Thompson Valley—while in Ontario, wineries are being established north of Toronto—some near Georgian Bay—and around Ottawa.
What can producers in existing wine regions do? In successful regions, climate, soil, and grape varieties exist in harmony, so change in climate requires change to soil conditions and varieties. The most important quality of vineyard soil is its drainage and water retention capabilities: vines generally do best in well-drained soil, but they also need access to water during the dry periods of the growing season. Various forms of irrigation can deal with normal periods of dry weather, but recent extended droughts in California, South Africa, and Australia have forced wine producers to take extraordinary measures to save their vines (although in some cases, they have had to let vineyards die).
In Canada’s main wine regions, vineyards are being planted farther north than ever before: the newest official wine regions in British Columbia include the province’s most northerly—Lillooet, Shuswap, and Thompson Valley.
But climate change is more than just a matter of warming. Rainfall patterns have changed, too, and frequent episodes of heavy rain in some regions have caused erosion in vineyards. Devastating frosts have become less predictable. The polar vortex—a large area of low pressure and cold air around the Earth’s poles—killed entire vineyards in Ontario and New York state in 2014. It is thought to have extended that far south because of warming temperatures and loss of sea ice in the Arctic. That year, almost all the vines in Ontario’s Lake Erie North Shore wine region died. It takes two or three years to re-establish vineyards that can produce commercial yields, so regular winter kills of this magnitude would call into question the viability of entire wine regions. Ontario’s wine landscape is dotted with wind machines that mitigate the effects of frost by mixing cold air at vine level with warmer air above, but they can only do such much.
Vines can also be managed to some extent. In many regions, they are covered with shade netting to protect them from long hours of sunshine. Meanwhile, vines planted in rocky soils that accumulate heat during the day and radiate it to the grapes at night are being trained to grow higher to lessen the impact.
Planting grape varieties and clones that are more tolerant of warmer conditions is another response. In Australia, California, and elsewhere, plantings of grenache, mourvèdre, tempranillo, and other Mediterranean varieties—tolerant of that region’s hot, dry conditions—have been increasing. Even the conservative body that administers France’s wine appellations is allowing limited plantings of new varieties “for climate and environmental adaptation” and to prepare for a “controlled evolution” of the grape varieties in France. In B.C.’s Okanagan Valley, clones of chardonnay originally bred for the cooler conditions of Burgundy are being replaced by clones tailored to the warmer temperatures of California.
In Chile, where wine regions are named for valleys, vineyards are being extended far up the hillsides, even though this often means water must be pumped hundreds of metres up to provide irrigation.
Another strategy is to plant vineyards in cooler areas. Brown Brothers winery in Australia’s Yarra Valley is located in one such area, but it will soon be too warm to produce pinot noir and sparkling wines. As a result, Brown Brothers has planted vineyards in Tasmania, which is already known for its sparkling wines and pinot noirs. Ontario’s and B.C.’s more northerly vineyards are part of this movement, as is the growth of Nova Scotia’s wine industry.
Elsewhere, producers are looking for sustainable growing conditions at higher altitudes or in coastal areas cooled by ocean breezes. Argentinian wine producers have planted many vineyards in the foothills of the Andes, some as high as 3,000 metres above sea level. Patagonia, in the cooler south of the country, is becoming more important as a wine region, and Argentinian producers have recently begun to plant vineyards near the coast. The same search for cooler regions is taking place in Chile and South Africa. In Chile, where wine regions are named for valleys, vineyards are being extended far up the hillsides, even though this often means water must be pumped hundreds of metres up to provide irrigation.
Wine producers’ arsenal of responses to climate change is extensive—and also expensive, if it involves buying new vineyard land and investing in new technologies. The big producers, who make wine for the mass market, have the means to adapt relatively easily, as do small producers owned by corporations. Those at greatest risk are the small, family-owned, artisanal producers, which are often undercapitalized.
It’s a bit early to say that in a few decades Bordeaux-classified growths will be mainly grenache, that Lodi old vine zinfandels will become museum pieces, and that Ontario will be producing high-octane red wines.
For consumers, there are many possible consequences. Some small wine regions might disappear and others emerge. New grape varieties will be planted in some existing regions. There might be a tendency to produce more concentrated wines with higher alcohol levels. Prices could rise as producers invest in new vineyards and measures to deal with climate change; smaller, marginally profitable (or unprofitable) wineries that can’t make these investments might go out of business.
As these and other changes play out gradually over the next few decades, consumers will be able to adapt to them. But changes there will be. It’s a bit early to say that in a few decades Bordeaux-classified growths will be mainly grenache, that Lodi old vine zinfandels will become museum pieces, and that Ontario will be producing high-octane red wines. But everything is on the table—just as many of today’s wines could well disappear from yours.
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