In classic (French) winegrowing tradition, there are three ingredients that combine with a grape variety to influence any particular wine’s style: The weather, the soil, and the topography. This combination is called the terroir, and it gives each wine a flavor specific to the place where the grapes are cultivated. For example, a Merlot grown in Bordeaux won’t taste the same as a Merlot grown in Napa Valley, which will, in turn, differ from Merlot grapes grown in Washington state.
Terroir is now being drastically influenced by climate change caused principally by human activities. Wine lovers should be paying close attention to the increasingly dire reports on global climate change. If scientific models are correct, the California wine industry could be forced to undertake dramatic measures to adapt, either relocating production sites or shifting to heartier (and less desirable) varieties.
When temperatures and levels of CO2 increase, grapes ripen more quickly resulting in fruit with higher concentrations of sugars, lower acidity, and higher pH levels. What the wine industry is facing is not only a change in temperature but a change to the very ingredients of the terroir. Resulting wines end up being less delicate with higher alcohol content.
Average temperature levels are rising, and even more concerning, so are extreme vine and grape-harming weather events, such as prolonged droughts and hail storms. Bordeaux, for instance, was hit with severe hail storms in May 2018, damaging thousands of acres, while in 2017, the region suffered destructive frosts. Increasingly, winemakers in places such as Napa, California’s Central Valley, and Oregon’s Willamette Valley acknowledge that climate change poses not just a future risk, but a clear-and-present trend. Climate change impacts of simultaneous volatile weather events such as cold snaps, sharp frosts, downpours at key points in the growing season, and new insects thriving in warmer conditions are all major threats to the productivity of the industry, especially for climate-sensitive grapes.
And not just in the US; by 2050 it’s predicted that large areas of southern Italy, the Iberian Peninsula, Australia, South Africa, and southern France will no longer be able to support the growth of wine grapes because of the hotter weather. The Champagne region in France, where cool-climate grapes are grown, is especially vulnerable to rising temperatures that have caused the grapes to produce more sugar, more alcohol, and less acidity. Acidity is vital to the crisp flavor of the finest Champagnes.
What does this mean to fine wine lovers?
The impact of climate change on wine making is both a threat and an opportunity. On one hand, traditional wine making regions may be adversely affected. On the other, new regions will become more attractive. Initially, warmer temperatures were welcomed in Europe. In France, the last 10 years have produced a series of excellent vintages, especially in Bordeaux. Germany’s Rhine and Mosel Valleys are now producing some of the best wines they’ve ever made, according to some wine consultants.
While they may spell trouble for your favorite wine, the effects of climate change are also opening up new countries to the wine business. United Nations models predict regions with perfect winegrowing conditions are shifting, and vineyards are beginning to pop up in southern England, Denmark, Sweden, and Finland.
Some wine lovers joke and scoff at the idea of fine English wine. Yet English wine producers have been winning plaudits and top international prizes in recent years – including for sparkling wine – and they owe it partly to climate change, as the climate in southern England has shifted from a marginal, cool climate to an intermediate climate.
Not all winemakers are complaining. In North America, while fine Napa Cabernet may be at risk, other North American regions may benefit from the rise in the average temperatures including British Columbia, Washington State, Long Island and the Finger Lakes in upstate New York, as well as Niagara-on-the-Lake and other parts of Ontario, Canada. Winemakers in the Okanagan Valley east of Vancouver are planting red wine varieties once deemed unsuitable to the region, such as Merlot and Pinot Noir. Okanagan’s wine industry will likely flourish in the decades to come. In Oregon’s Willamette Valley, growers once worried about their Pinot Noir grapes reaching full ripeness by the end of the short growing season. Now they have opposite concern, namely, that their grapes don’t ripen so quickly they lose some of their delicate character.
Winemaking bears small responsibility for a warming planet, yet the wine industry has a large stake in progress reducing the global emissions that are causing the problem, and there is much the industry can do, not only to lessen its own carbon footprint, or to adapt to the changing climate, but to become advocates for more aggressive emission reduction policies by governments around the world.
Winemaking contributes to greenhouse gas emissions, partially through cooling of fermentation tanks in modern winemaking but primarily through packaging and transportation to markets. Some wineries have installed solar energy.. he industry’s water footprint is likely even greater than its carbon impacts, and so in some regions such as drought-stricken California, Spain, and South America wineries capture rainwater, store it in fermentation tanks when not in use and reuse the water for irrigation.
Grapes are ripening sooner than normal and being harvested between 2 and 6 weeks earlier in parts of Germany, California, Italy, and France. The Champagne industry has started to shrink its carbon footprint – the average weight of an empty Champagne bottle has fallen from 900g to 830g, and the level of CO² released per bottle made is down 15 percent.
Elsewhere the wine industry is starting to take other steps to reduce its carbon footprint – shipping wine in bulk to be bottled in destination markets. New formats for wine delivery and alternative packaging are innovations that can offer taste quality, eliminate waste and reduce carbon footprints, such as wine in keg for wine-by-the-glass service in restaurants and wine bars, and bag-in-box wine for home consumption.
Here consumers can play a role by seeking out lighter weight bottles. A heavier bottle does NOT signal that the wine inside is of higher quality! In fact retailers in Ontario and in Sweden prefer to sell bottles of lighter weigh.