The Effect of Climate Change on Viticulture

As I sit and write this, it is ghastly hot and humid. It’s only June 1. In fact, it’s so hot and humid I had an inkling to take my laptop downstairs and sit in the dusty, dirty basement just to find some cool. But my dog refuses to go down stairs of any kind, and I feel bad abandoning him to the humidity, so now we sit together in my office sharing a fan.

As midwesterners tend to do, when we’re making small talk and harrumphing about the weather, it often comes up as a little joke, “that’s climate change for ya!”

Between this heavy weather and the fact that during my June Wine Wednesday research I came across the topic twice, I thought we’d spend this time diving into how Climate Change is affecting the beverage industry, particularly focusing on wine.

(Side note: If you don’t follow me on Instagram you’re missing out! Every Wednesday we do a fun mini-dive into a wine related topic. Follow me and come learn with us.)

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There is an incredible amount of research out there on this, which is absolutely amazing, but warning: this blog post is not that. It’s high level, slightly informative, and will hopefully peak your interest enough to click on some of the actual research I’ve linked down below in the reference section.

The Grape Crop

Grapes are a finicky crop; they’re very sensitive to pretty much everything in their environment, from heat at the right time (they love a diurnal shift), to morning fog, soil composition, and the amount of breeze they get on any given day.

Because they’re so picky, wine grapes grow in narrow geographical and climatic ranges where temperatures during the growing season average 54-72°F.

And some grapes are very finicky. For example, Pinot Noir is perfect in just a 4°F climate niche. 4°F. While it can grow in cooler or warmer climates, the differences in taste are very apparent. So for vineyards looking for Pinot consistency (and consistent taste is key for large scale producers) any change in temperature is scary.

In the United States alone, the average growing season temperature has risen 2.0°F since 1970. That already throws the precious Pinot into turmoil.

The Expanding Map

One aspect of global warming that I didn’t really consider until I started looking into this, is that the map of where we can effectively grow grapes is changing.

Mostly, that map is expanding.

A great example of this is England’s now flourishing sparkling wine industry. Thirty years ago England didn’t have a wine industry at all - their cool climate was not ideal for grape growing - but with warming and elongating summers, it was just a matter of finding the correct, early-ripening varieties and the game was afoot.

In fact, hectarage under vine in the UK has gone up 70% in just five years. As of 2021, the region has 3,758 hectares of grapes planted; that number doubled in eight years and has more than quadrupled since 2000.

And it’s not just England. Winegrowers are now looking to snatch up land in places like Denmark, Sweden, and even Finland as temperatures increase and those areas which previously would not support the grape crop now look quite appealing.

The great wine regions in France are also seeing warmings affects. A truly superb vintage year would come along every once in a while, but with warmer growing seasons in that region it’s been easier and easier to produce consistently exceptional wines.

Now, some of this sounds great, right? More places can make wine! And places already known for making great wine are making more of that great wine!

But the problem is that while the map is creeping outwards, some of those traditional winemaking regions are now too hot or have too big a shift in temperatures to continue effectively growing grapes. Those varietals we covered up above - pinot and chardonnay in particular - are mainstays of some particularly affected regions (think California and France). These are called “premium wines” and they’re in trouble. Viticulturists may need to completely change the varietals they’re planting, and those premium grapes we know so well may be left by the wayside.

Researchers found that extreme heat in the growing season due to climate change could reduce areas that are currently capable of producing premium grapes by 50%.

And these changes are coming much faster than anyone predicted. Eight of the ten warmest years on record have occurred in the last decade. In the last two years alone, there have been record temperatures from far North America to Italy, wildfires in Australia, California, Portugal, and Greece, floods in Australia and Germany. All these areas are have large viticultural industries, and all are feeling the climate change squeeze.

A very educational (and tasty) weekend can be had if you explore the wine region of the Okanagen Valley in Canada. — Photo by Kym Ellis / Unsplash

How are Growers Coping?

The hellfire and brimstone described above is definitely scary, but wine isn’t gone just yet, as grape growers are adapting and learning how to cope in several innovative ways.

Go Up

Similar to the expanding map of entirely new wine regions, viticulturists are also planting in new areas of their traditional regions which never saw grapes before: higher elevations.

There’s no magic altitude for grape growing, as the sweet spot will entirely depend on the other aspects of a region’s climate, but in general as the earth warms, vineyards are moving higher.

For example, in the Catalonia region of Spain (known for it’s delicious Cava, Grenache, and Tempranillo) Familia Torres Winery is now planting vineyards in the Pyrenees foothills, at 3,000-4,000 feet, something that would have been impossible twenty-five years ago.

Similarly, in the Walla Walla Valley of Washington State, growers are now trying to grow at 3,000 feet, which is higher than they’ve ever attempted before.

While going up definitely helps keep the necessary diurnal shift in place, it creates new issues like poor soil on the slopes and challenges with water scarcity.

I am passionate about photography since I am a child and my mother who is one of my biggest fans asked me for a landscape, so we went together for this photo shoot in the Lavaux vineyard, which is a wonderful place in Switzerland, inscribed on the UNESCO World Heritage (near Lausanne city). The yellow color of autumn was incredible, it was also a beautiful afternoon with my mum and the picture is now in her room. — Photo by Alissa De Leva / Unsplash

Limit sunlight

No, they don’t put up giant sunshades or put little hats on the grapes (though that would be adorable). Growers limit sunlight by where they plant their vines.

It’s been pretty much gospel in the viticultural world that you want to plant vines on a slight slope, with rocky/sandy soil, facing south or maybe southeast. This would ensure the vines received the most sun and warmth during the growing season.

But as the growing season gets longer and hotter, growers are now contemplating throwing the gospel out the window, and starting to look for different slopes.

Those south-facing slopes are now actually producing overripe grapes which, and while that's good in some cases like Noble Rot wines, it's definitely not the desired norm. So growers are shifting, and looking for different geography in their regions.

Grow different grapes

While all grapes are needy and difficult crops in their best of times, there are variations in when certain grapes ripen, which can help growers decide which grapes are best to plant where.

Even outside of the climate change crisis, grape growers have experimenting with creating different varietals. The University of Minnesota and the University of Wisconsin-Madison have made some very interesting hybrids and crosses for better growing here in the Midwest.

We're a cool climate here, with a shorter growing season and harsh winters. But these created varietals are early ripening and (somewhat) frost resistant. Using manipulated grapes like these may become more of the norm as vineyards move to different areas and the climate continues to change.

Plants in beakers — Photo by CHUTTERSNAP / Unsplash

And of course there's the classic example of the European viticulturists using the N. American vitis riparia rootstock and grafting traditional vitis vinifera to it in order to take advantage of riparia’s natural resistance to phylloxera.

So, using new and different grapes is not unheard of. But the point again is that some of those traditional and finicky varietals may eventually be phased out, or changed entirely from what we know now.

Chardonnay grapes make up most of the highly desired French Champagnes, but as those become harder and harder to grow, winemakers are looking to include different varieties. The problem they run into is that in regions like Champagne or Bordeaux, there are laws about what type of grapes can be included in certain appellations. Winemakers can’t suddenly decide to include liliorila grapes and still call their wine “Champagne”.

Of course, authorities responsible for these laws are monitoring regions, grapes, and the affects of climate change. But appellation restriction changes are slow coming.

Predictions are Impossible

Yet another big frustration for the industry is the difficulty in predicting the weather. For any type of farmer, experience and knowing climate trends over many years is key. But with climate change now taking center stage, those meticulous records of climate patterns that were kept over decades or centuries just aren’t helpful anymore.

And it isn’t just about warming.

Hail and rain are causing wetter than normal conditions during the summer in regions like Barbaresco and Barolo, which previously had dry growing seasons. This is bringing in pests that never used to be problem.

California and Australia - both massive players on the wine stage - now go through draughts and large scale fires regularly during the growing season. And this affects the vineyards in even weirder ways than just being afraid their crop will burn down or there won’t be enough water; smoke damage is affecting vines as well, and in a larger region than just those in the direct path of the fire. Smoke from these fires can travel thousands of miles.

Bushfires below Stacks Bluff, Tasmania, Australia — Photo by Matt Palmer / Unsplash

Smoke exposure actually changes the chemical composition of the berries. Instead of whatever fruity, sweet, or acidic taste they were supposed to show, they will now possess aromas such as “ashy”, “smoked bacon”, or “burnt wood”.

While I love bacon, I don’t want it part of my wine.

A great example of the impossibility of weather predictions hit really close to home this year. Wollersheim Winery, and Wisconsin classic that’s been around since the early ‘70s, lost almost their entire red grape crop this year due to fluctuating temperatures.

In Spring 2023, Wisconsin saw a long stretch of unseasonable warm weather in early April, followed by a sharp drop in temperatures later in the month and early May.

"In the spring, 80 degrees Fahrenheit for 10 days is nothing good," Winemaker Philippe Coquard said to WKOW 27 News. "It will bud earlier. And then we could get a frost and lose quite a bit of the crop."

Coquard went on to say it’s the worst year he’s seen in nearly 40 year of winemaking in Wisconsin.

Weekly Adventure

There are so many things I could request for your weekly adventure - so many ways you could help combat climate change within your own little footprint. But I know these things get overwhelming fast.

So, I encourage you to read through the links below and educate yourself further on how even the slightest change in climate is affecting agriculture.

And if you have some mental and emotional space after that, check out the United Nation’s guide to 10 steps you can take to make a difference.

In sincerety,

Molly