Toward the end of John Maynard Keynes’s opus on general economic theory, the text turns to one of his more philosophical observations: “Practical men, who believe themselves to be quite exempt from any intellectual influences, are usually the slaves of some defunct economist.”
The corollary for wine—whereby winemakers and sommeliers are often under the influence of old professors of viticulture and enology, or arcane traditional craft—is self-evident. The intellectual history that produced wine knowledge is often hidden in the methods section of a decades-old paper or the pages of a history book covering the birth of enological paradigms.
I wanted to write a book that not only covered the researchers and other figures behind the knowledge of wine but focused on the disagreements within the world of wine, because it is through this dialectic that we can progress closer to truth. As I come from one of the benchmark producers of California, Ramey Wine Cellars, which is more known for scientific rigor, the research project seemed natural and engaging.
Over years of inquiry, I distilled various topics of conversation into the foundational tensions at the heart of the issues. Although most of the topics had been debated for at least a century—think biodynamics, regional wine rules, naturalness, or good taste—the topic of climate stood out as different because of its relative historical novelty.
The question at the heart of the issue is to what degree warming or climate change can impinge on or eliminate a wine region. At worst, as some have argued, climate change will eliminate some of the classic winegrowing regions from the globe, making them unsuitable for agriculture. A more reserved but nonetheless grim prediction is that global warming will render the wines of certain places unrecognizable from what came before.
Those opposed to these predictions suggest that terroir is more linked to soil as opposed to climate or that vintners will be able to minimize the disruptions to sustainability and wine flavor by using farming tools or techniques.
This is an essential debate in wine because it gets to the issue at the center of any wine: the endurance of typicity and character. If a region is built on quality, and that quality is based on climate, what happens when it all goes to chaos?
–Alan Ramey
Kees van Leeuwen has worked on over one hundred peer-reviewed papers and is considered one of the foremost experts on terroir and the effect of climate on vineyards. His 2024 literature review, which he coauthored along with several other academics, sent a tremor through the wine world when it reported that by the end of the twenty-first century, traditional European winegrowing regions might shrink by 20 to 70 percent. Reflecting on the possibility of vintners trying to adapt their vineyards to recreate the types of wines that came before, van Leeuwen pronounces, “You can change some practices in trying to push it back a little bit, but you will never go back all the way.”
Understanding the historical context of how certain sites came to represent quality in Bordeaux helps with comprehending the implications of climate change around the world. In the right bank of Bordeaux, which is known for Merlot-based blends, the crown jewels—according to market value for wine—are Saint-Émilion and Pomerol. Van Leeuwen and one of his PhD students showed that the lesser-known satellites around Saint-Émilion were cooler, which may explain why they did not develop to be as prestigious as the towns their names suggest they orbit. “Now they are definitely catching up,” he says, though other factors like soil, elevation, and vineyard management make prediction difficult. He also suspects that western Bordeaux, which is closer to the ocean, will have the potential to increase in quality.
More broadly throughout history, southern- and western-facing slopes performed better because they received more sun, but now, given the increasing specter of heat waves associated with climate change, the exact blessing that their ancestors were grateful for might fill a modern Bordelais vigneron with angst. The sun also burns.
Though achieving enough ripeness to ensure quality has been the goal for centuries, there were early clues that some of the better-suited sites were better protected in years when heat waves did strike. In speaking of work he did with his PhD student Laurede Rességuier, van Leeuwen notes, “We saw that on the limestone plateaus in Saint-Émilion—so Ausone, Canon, Clos Fourtet, Pavie—in fact, the maximum temperatures are lower because it’s just more windy.” This finding raises the question of whether factors like wind might shield some regions against the particularly damaging effects of a heating planet or whether even these revered sites will be undeniably altered—and perhaps for the worse.
Others argue that climate change will be even more severe, going much further than affecting wine flavor. This position was laid out in 2013 when Lee Hannah, who holds a doctorate in environmental science and engineering, published a paper with several colleagues that grappled with the implications of climate change in wine. In a scenario where climate change accelerated rapidly—a not unlikely possibility—the researchers estimated that classic wine regions would lose 25 to 73 percent of their land, claiming that it would become unsuitable for grapes. Hannah noted that grapes grown in warmer climates need more water and so vineyard owners trying to maintain their crop in the face of climate change might further burden water resources.
Using the example of Chile, a country with a rich and thriving winegrowing history, Hannah and his colleagues stated that 95 percent of the winegrowing regions of Chile are already under water stress and that climate change could further exacerbate the problem. With predictions of decreased rainfall and dwindling snowpack in the Andes Mountains, a bleak picture emerges of an already threatened region pushed to the brink.
In addition to making these pessimistic projections for much of the current wine world, Hannah and his colleagues went on to suggest a series of new regions that would be suitable for wine. In short, he predicts a march toward the poles. In the northern hemisphere, England and the Canada–US border area around the Rocky Mountains would be among the winners, and, in the southern hemisphere, Tasmania and Patagonia could become larger players in the quality-wine world.
The paper not only critiques the potentially greater environmental footprint of existing wine regions under climate change but also elucidates how new vineyard plantings toward the poles could be harmful. Any agriculture, including grapevines, impinging on native habitat is seen as an ecological loss for flora and fauna. In China, which the paper predicts will become a better wine region, Hannah and his coauthors point out that these agriculturally undeveloped regions are currently habitat for the Giant Panda and vineyard expansion might therefore be harmful.
This paper caused a notable stir, and Kees van Leeuwen was one of several academics to write a response, stating that its predictions of the demise of current wine regions went too far. Pointing out methodological errors, they castigated the paper, claiming that several regions in France are growing wine successfully and sustainably despite being within Hannah’s “unsuitable” range. They left some of the environmental impact claims unchallenged.
Other burgeoning wine regions might view further vineyard expansion as a boon rather than a harm. In the United Kingdom, where tentative plantings of early-ripening varieties have been increasing, many vineyards are planted on existing farmland, replacing one crop with another, so claiming that local species are being negatively impacted would be a stretch. The same is possible for other regions with existing agriculture. Additionally, regulation and responsible vintners may limit the expansion of new vineyards into virgin forest, decreasing the impact and likelihood of new plantings.
Some may further criticize the Hannah study, citing these circumstances as a reason to doubt the possibility of species loss. And any new vineyard plantings might have the positive effect of enlivening local cultures and reinforcing economic stability. But others would argue that there are already examples where vineyards have been expanded into unsuitable locations, causing environmental damage, and we will continue to see how it plays out as temperatures rise around the world.
* * *
In the twenty-first century, Californians have begun to grapple with what climate change means for their backyard. At first there was a sense that climate change might be a boon for many of the state’s varied grapegrowing climates. Between 1951 and 1997, there was increased sugar maturity and higher-quality wines, and given the observed 14 percent increase in growing degree-days over this period, climate change was suspected to be the causal force. Before 1976 frosts were reported more regularly, with poor wine quality ratings as a result, but after 1976 frosts became much less common.
Julian Alston, the distinguished professor emeritus in the Agricultural and Resource Economics Department at UC Davis and director of the Robert Mondavi Institute Center for Wine Economics, and Sarah Smith, a postdoctoral scholar specializing in the microeconomics of agriculture and resources, are less optimistic.
Alston and Smith distributed a working paper in agricultural economics in which they tried to account for the randomness of climate change. Rather than measuring the mean average temperature, which has been the usual tool of agricultural climatologists, the researchers looked at how the market was affected by what happens in the extreme events that are expected to come more often.
Although many farmers might not need an economist to tell them a heat wave is bad for vines, it is difficult to understand what extreme weather may do to wine prices. By getting granular about pricing and temperatures, Alston and Smith attempted to measure how hot a heat wave needed to get to change wine prices. Using a large database of Californian wines sold on the secondary market, Alston and Smith found that as degree-days above 35 degrees Celsius (95 degrees Fahrenheit) increased, wine prices decreased and critical appraisals of the vintage went down.
The difficulty that any economist will readily admit is that wine pricing and vintage scores may be a poor proxy for wine quality, but in a world where wine quality is so hard to measure, particularly over time as tastes and styles change, its value may be better than nothing.
One of the challenges of correlating global warming to qualitative changes in wine is accounting for all the variables. For example, during the second half of the twentieth century, when some research found promise in climate change, there had been a concurrent investment of brains and money reforming California’s “wild west” viticulture, which could also account for some of the improvements seen across wines over that period. Similarly, as critics such as the notable Robert Parker awarded high scores to riper wine styles, many sought to emulate these wines, making it difficult to tease apart the impacts of a warming climate from a cultural pursuit of ripeness.
Looking at long-term climate models and assuming no adaptive changes from growers, Alston and Smith predict that Napa Valley Cabernet prices will decrease. Alston poses the question: “The projected climate for end-of-century in the Napa Valley is Fresno and so the question to ask a winemaker is to say, well, do you think you could make wine anything like the quality you’re making in Napa today in Fresno?”
The use of Fresno as an example is not accidental. A part of the San Joaquin Valley of central California, this hot inner plain produces 100 percent of the state’s raisins, a hint at its status as a place known for inexpensive wine. The implication that Napa’s climate would mirror Fresno’s is devastating. Sarah Smith is cautious, and qualifies their findings. “You have to assume there’s no adaptation, and that’s a very strong assumption. We do think that there will be a lot of adaptation.”
An essential question raised by climate change is whether vintners have any power or obligation to fight climate change. Some wineries espouse the benefits of their soil practices, which they claim allow them to sequester carbon. Others have built solar arrays, recycle their water, and have changed their packaging, among other practices. Sometimes the collective impact of farming is used as a moral imperative for vintners, who as part of the world of agriculture, it is claimed, have a responsibility to step up.
Given the relatively minuscule effect the wine industry has on climate change relative to most other industries, there is an argument that these gestures are more for marketing than to create any real impact. Critics can point out the irony of a producer employing meticulous environmental precision in a vineyard, only to bottle a product in heavy, relatively inefficient, and energy-intensive small containers, send it around the world, and fly around the world promoting it. The level of hypocrisy, some might claim, is quite high. Some serious environmentalists might challenge those in the wine world that if they cared about the environment they could stop altogether and return their vineyards to forests, which would do a much better job at carbon sequestration than any vineyard practice.
While some might be persuaded by this type of argument, others might view stopping the capitalist machine as unrealistic and not helpful. The better path, they say, is to try to balance human wants with attainable environmental goals. Even the smallest ecological effects matter, and the only way forward is to foster this attitude across industries that all must do their part. Given that wine is one of the more visible and sexy agricultural endeavors that tourists actually want to see, some can argue that even if the environmental effects might be small, the example set by the wine industry has an outsize impact. Practicality and idealism continue to clash.
The twin questions more immediately affecting the wine consumer are whether existing wine regions and vineyards can (and should) continue to be sustainably farmed and whether the wines can continue to command respect. Part of the reason this debate remains mysterious is that climate change continues to progress at an uncertain pace; it’s unclear when and how quickly adaptation will need to take place. Given the incentives for many vintners to preserve the status quo for as long as possible, it is also unclear how many environmentally beneficial changes are currently possible but aren’t being discussed. Since adaptation is not a big selling point for most wineries, it’s often publicly addressed with simple platitudes about sustainability before marketers revert back to the usual selling points.
There are still a number of practitioners in the industry who regard climate change as an overblown concern. Though data suggests that the climate has changed somewhat, the fears are exaggerated, this group argues. And even if it is a long-term, serious threat to the planet, grapevines are resilient, they argue, farming practices make a huge difference, and all the cultural and intellectual know-how can play a large role in ensuring that babied vines turn out amazing fruit. New regions might spring up, but they are in for extreme weather at the poles too, and it’s nearly impossible to uproot all the generations of savoir faire to a new place and start from scratch. And yet, this move seems to be in motion, and the wines have entered the world stage.
The fact that Tasmania, Patagonia, and the United Kingdom, to name a few of the newer entrants, are making wine and gaining investment can be construed as evidence to support those who believe the pendulum may be swinging to new terroirs. Blind tasting’s value will grow as entrants and old hands seek to test and retest assumptions. Vintners in new wine regions can exchange information and spread the word in the same way that other regions have done in the past. And environmentalists will continue asking hard questions about viticulture’s sustainability around the world, even if the industry can only effect so much change on its own. In this sense, every new vintage from every wine region, drunk in restaurants, wine bars, and living rooms around the world, is an opportunity to assess whether the glass and its origin are worth fighting for.
This excerpt first appeared in Pressing Matters, written by Alan Ramey and published by Académie du Vin Library in April 2026. It has been minimally edited for style, length, and audience. Used with permission.
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