Wine is first and foremost an agricultural product: climate change impacts the health of the vines, the taste of the grapes, and the quality of the finished product. So while grapes’ sensitivity to climate is what makes wine so exquisite, it’s also what makes it incredibly sensitive to climate change.
In fact, wine demonstrates perfectly how climate change is transforming centuries-old traditions and the steps taken to counter and adapt to shifts such as hotter summers, warmer winters, and increased violent events such as hail storms and spring frosts. Of course, some areas are benefiting. Germany has begun enjoying better yields of plump and juicy grapes. England has been able to join the global wine world. Bordeaux and Burgundy expressed much excitement for the warm 2019 vintage. In truth, however, these are thin silver linings to a continuously worsening viticultural challenge.
Traditional wine regions can no longer support their usual grapes. Merlot as we know it is on the verge of extinction, French wines will become more alcoholic and less aromatic, and the entire industry has begun experimenting with new regions, new grapes, and new techniques. Below are some of the key changes caused by climate change that we are seeing in the wine world today.
Grapevines thrive where they are challenged, whether in poor soils that force roots to go deep for moisture or in marginal climates where they have to struggle to ripen. In fact, some of your favorite grapes come from these borderline environments where there is a balance between low yields and phenolic ripeness.
Today, areas once considered too cold for fine wines have now become the ideal growing regions: wine producers in the Northern hemisphere are moving north, whilst those in the Southern have moved south. England is a perfect example. Just 30 years ago no one was talking about English sparkling wine. Today, they are a world-class sparkling wine industry thanks to a warmer climate and chalky soils that mirror those of France a century ago.
Typically the best vineyards have been found at 30-50 degrees latitude. However, as global temperatures continue to climb these ideal areas are moving further and further from the equator. This is why we’re seeing vineyards in England, Belgium, Denmark, and Patagonia.
Not only are vineyards moving further from the equator, but they’re also going up higher. Producers have looked to plant at altitudes that were once inhospitable to wine grapes. Today, however, these higher elevations mean that intense heat lasts for shorter periods and temperatures at night are cooler. In short, going higher means an increased diurnal shift which helps grapes ripen at a more even pace over a longer period.
In the 1990s, the high-altitude vineyards in Argentina were only at 5,000 feet. Today we’re looking at 5,000-11,000 feet. Likewise, in the Walla Walla Valley of Washington State, an area where growers focused on low elevations, vineyards are being planted at 3,000 feet in order to retain the acidity in their wines.
Wine producers have kept meticulous records of their harvests. Using these records we can see that temperatures have increased so much that harvests begin an average of 13 days earlier than they did prior to 1988. Due to these increased temperatures, grapes are ripening faster. Unlike other fruits, however, this makes grapes more vulnerable to damage as their delicate skins can burst easily if harvested too late.
This is also what makes grapes more susceptible to fungus and rot. If crops become infected, it can damage the vineyard for future seasons as fungus can remain on the roots.
Not only that but when wine grapes ripen too quickly, it throws off the wine’s flavors and alcohol content. Climate after all dictates how a wine tastes. Shorter harvesting periods mean higher alcohol contents and lower flavor profiles.
Anyone in agriculture knows that experience counts for an awful lot. Whilst no two years are the same, there are general trends that farmers can use to guide their growing and harvesting plans: those with experience know what to expect. Today, that is no longer true. Once rare devastations have become almost normal and wine regions have to learn how to deal with them on a regular basis.
Look at Burgundy, for example, they've experienced several disastrous vintages due to hail. Now they’re looking at installing systems to prevent the formation of hailstones by shooting heated silver iodide at storm clouds. Another solution is putting up bird netting in an effort to protect their grapes.
Italy has experienced sunburnt crops at an increasing frequency. Likewise, Southern Australia recorded the hottest summer in 2019 since 1910, which brought about an 8% loss in white wine varieties. But it’s not just about heat. Whilst freezes may be less frequent, they will likely be more severe, and their decreased frequency can encourage the spread of pests and diseases that would normally die off during cold seasons.
Portugal, New Zealand, and California on the other hand are also facing severe floods that can leave vineyards underwater. Meanwhile, those areas inland will become more prone to groundwater salinization and drought. So while grapevines thrive when challenged, too much stress can cause the vine to stop producing altogether.
So what can wine growers do? Adapt and experiment. In areas where water can no longer be taken for granted, growers must look to grafting their vines onto drought-resistant rootstocks or selecting other grape varieties that are more suited to the new climate (see next section). However, for those who have the capacity to do so, they can look to move their vineyards entirely. Whilst the original formula dictates planting on hillsides that face south or southeast to receive the most sun, today this formula needs to be switched. Vineyards need to face north and be at higher elevations to minimize exposure to the heat of the sun.
Of course, for many winegrowers, new vineyards in cooler environments simply aren’t an option. Instead, they can look to growing varieties more appropriate for the changing climate. So while it may seem impossible to imagine Bordeaux without Cabernet Sauvignon or Champagne without Pinot Noir or Chardonnay, the prospect of a warmer future will likely require these regions to try something new.
This is already happening in Bordeaux and Napa Valley on an experimental level. In fact, we can see the severity of the situation by the involvement of Bordeaux. In Old World regions, where grapes and blends are prescribed by law, the idea of changing varieties is huge. Yet, in a 2019 General Assembly meeting the Union of Bordeaux AOC and Bordeaux Superieur winemakers approved a list of seven varieties of interest for adapting to climate change: Touriga Nacional, Marselan, Castets, Arinarnoa, Albariño, Petit Manseng, and Lilorila.
Likewise, others look at the possibility of engineering new grapes that can withstand extreme temperatures and develop flavors at a steady pace. If these get created, they would be easier to grow and could withstand the weather and even certain pests.
When it comes to slowing down or minimizing climate change, the biggest offender in the wine industry is packaging and transportation. This sector accounts for 79% of total emissions (it’s worth noting, however, that the wine industry as a whole contributes very little in relation to other industries). So it’s no wonder we are starting to see new methods of packaging for wine and the rise in popularity of canned wines. Likewise, glass bottles are becoming lighter and increasingly are being made domestically to reduce the back and forth in transportation.
Yet the impacts of these changes are unknown. The only thing we can know for certain is that it will get warmer, but we may be able to anticipate that heat before it hits us. Whilst each region is different, the one line that works for everyone is to cut carbon emissions. The winemaker Dan Petroski sums it up perfectly: “We know we can’t turn it backward, and we’re not even sure we can slow it down. But we have to try.”