Wine – a Californian dream – or nightmare?

Climate change is posing a serious threat to Californian family run vineyards.

Studies have shown that climate change will have a fundamental impact on weather patterns causing extreme temperature fluctuations and increasing the risk of droughts or floods. Given wine grapes’ sensitivity to weather conditions this will have a severe impact on the wine industry globally. Increasing summer temperatures can cause sugar levels in grapes to rise too quickly forcing growers to pick sooner or manipulate them at a sacrifice of tannin quality. Warmer temperatures increase the likelihood of pest epidemics, calling for expensive and potentially quality reducing chemical responses. Shrinking glaciers, melting snow and erratic, unpredictable rainfall cause water supply security and price concerns for this irrigation intensive industry.

The impact, however, is not homogenous across regions. Californian vineyards are especially affected by rising temperatures and growing days over 35 degrees Celsius. Suitable vineyard area of premium wine production in the US (mostly located in California) could decrease by as much as 81% by the year of 2100 [1]. Many people argue that wine is a luxury good and therefore less of a concern, however, the wine industry has a 57.6bn impact on the Californian economy and is one of its largest employers [2]. Tax laws further complicate the problem of rising temperatures as high sugar content leads to wine with higher alcohol content, which falls into a higher sales tax bracket. Many vineyards in California are family run with limited financial resources to adapt to the challenges posed by climate change.

One example of a typical Californian family vineyard is the Van Ruiten Family Vineyard in the Lodi Area of California’s Central Valley. 78% of vineyards in this region fall into the Winkler Index (a heat summation method used to classify the climate of wine growing regions) Class 4 and 22% into Class 5 [3], putting this area at an immediate risk of small temperature shifts having detrimental effects on wine production. The Van Ruitens produce a wide range of wines including Sauvignon Blanc, Chardonnay, Pinot Noir and Cabernet Shiraz. In response to the challenges posed by climate change the vineyard has taken a number of measures to reduce its carbon footprint by moving towards more Sustainable Farming Practices and eco-friendly farming techniques. They erected nesting boxes for owls throughout their vineyards allowing the owls to help keep the rodent population down without the use of poisons in the soil. The family also avoids the use of machinery in the harvest and 100% of the grapes are handpicked.

There are further steps the vineyard may consider to adapt its Operating Model. The wine growing process can be broadly summarised by plantation, soil management, canopy management and harvest.


Figure 1                         Source: self-drawn

In the Planting Phase the vineyard may consider mitigating the risk by changing its product mix (i.e. the grape variety). An Australian study found that temperature effects on tannin and PH levels were variety specific [4]. Cabernet Franc and Chardonnay experienced the greatest shifts in both, whilst Shiraz showed little change in either measurement. The vineyard could produce less of their current variety and replace it with more resistant grapes. They may consider moving their vineyard to slightly more protected areas by relocating within the same region or considering a new location. Due to the high costs associated with a move this would be a more long-term solution of last resort.

Canopy management refers to the management of the shoots, leaves and fruits of the grapevine and has a considerable impact on yield and quality of produce. It involves pruning, “training” (positioning) the shoots and cutting leaves to allow air and light to flow to achieve optimal photosynthesis and ripening. To protect from heat exposure, shading systems could be introduced. The vineyard could partner with technology companies to look at geoengineering their grapes in an ecological and sustainable way.

Soil management is another important aspect of growing wine. Adequate irrigation is essential throughout the ripening process. To avoid dependence on water availability during a drought, the Van Ruitens may consider introducing self-managed water storage system.

The harvesting period is typically adjusted to the ripening process of the grapes. Bearing in mind changes in climate when evaluating the harvest dates would ensure that the sugar level in the grapes and therefore lower alcohol content of the wine does not increase substantially. This would be advantageous from a tax perspective as mentioned above.

Especially for family vineyards environmental effects that reduce the yield or quality of their production are critical. They typically do not have the financial means to introduce high tech solutions. A community approach, in which small vineyards partner with other vineyards from the region to lobby the government for adequate support and to represent their interests could be a good way to strengthen their voice.

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[1] “Global Changes in Local Places: Climate Change and the Future of the Wine Industry in Sonoma and Napa, California” by K.N. Cahill, PhD Dissertation, Stanford University


[3] The SOMM (Sommelier) Journal, October / November 2015 edition, page 124

[4] “The impact of climate change on the global wine industry: Challenges & Solutions” by Michelle Renée Mozell and Liz Thachn Sonoma State University, Science Direct

[5] “The Future Impact of Climate Change on the California Wine Industry and Actions the State of California Should Take to Address It” by Jonathan Gatto et al., International Policy Studies Program, Stanford University

[6]“Effects of elevated temperature in grapevine. II juice pH, titratable acidity and wine sensory attributes” by Sadras et al., Feb 2013


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Student comments on Wine – a Californian dream – or nightmare?

  1. As a former California resident, I definitely find this concerning. Not only is wine a big consumer product for the state but the Napa vineyards draw a lot of tourism. I think the crux of the problem is that there is very little viable land for growing grapes worldwide, and the land that is viable (Northern California) is particularly valuable for that purpose. As climate change continues to affect this industry, do you think it will make other parts of the country viable for vineyards that were not previously? Will Oregon and Washington become viable spots for wine production as the temperate zone shifts north?

  2. This is a really interesting analysis of the Californian wine industry! I’m especially struck by the magnified effect climate has on family run businesses that are especially capital intensive. Your point about them not being able to easily pick up and move or expand their operations is very real; a larger corporation could pursue this strategy through an acquisition or by simply purchasing land elsewhere. A family owned business is not only constrained by resources, but also by ties to heritage and loyalty. I wonder if their product mix is also a reflection of that (i.e. historically they have always grown Chardonnay and therefore would be more reluctant to shift to a different grape mix). I really like how you broke down the various options in terms of the grape growing cycle—it seems that one of the most important elements is harvesting the grapes at the right time, since this both determines the ripeness and the sugar content (and therefore tax implications). As the business only handpicks grapes, this seems to be an extremely labor intensive task involving closely monitoring the weather and obtaining enough seasonal labor at the right now. I wonder how this will impact labor supply and demand as climate change continues to affect operations!

  3. Fascinating article, Estelle. I had no idea how the industry works – this was a fun read. I liked how the vineyard seems to be taking decisions that intuitively seem to compromise their ability to gain scale (not using machinery, handpicking) to increase sustainability. What I am curious about is the community approach – is there a concerted effort by the industry to work together to combat climate change? There are precedents in other industries (Auto, for example) – in an industry where the raw material (the land, itself) is shared, I would imagine there is heavy benefit to the industry collaborating in their efforts.

  4. I think your post focuses on a very important issue. You are doing a nice job highlighting how rising temperatures and climate change are putting the wine industry at risk. California’s wine industry is a $60b industry and it may be misplaced because of climate change. I love how you are breaking out into specific buckets very concrete things that each winery can do, no matter the size: planting, canopy management, soil management, and harvesting. One very interesting point that you made is about community organizing. It is true, global warming may inspire and force many industries and players in those industries to organize in order to fight global warming.

  5. Love how you spoke to the effects on each grape variety of wine!

    Indeed, climate change is threatening the artful balance between sunshine and humidity. Too much sun in the vineyards will affect the quality of the produce. Too much rain (or none) will affect quantity. As such, in France it it said that grapes are now harvested 2 to 3 weeks earlier than 30 years ago as Springs become warmer, accelerating the flowering stage and the ripening of the fruit. The more the grapes are exposed to sun, the more concentrated in sugar they become, making them more highly concentrated – mostly above 14 degrees nowadays. And yet, some usually more acid varieties are actually benefitting from warmer temperatures. Champagne for instance is not complaining. And neither are we.
    Nonetheless, these effects are dramatically changing the wine cartography. In a century, wines from the South of France could resemble those found in Sicily and the production of Bordeaux wines could shift to… well the United Kingdom or the hills of central China. Yet another reason to be concerned.

    Check this out:

    Source: The Guardian, Climate Change Wine Production, 4/8/13

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