The good news, I guess, out of a new assessment of global warming's impact on viticulture is that we'll still be able to grow grapes and make wine somewhere on Earth, even under the hottest scenarios.
The weird news is that vineyards may need to be transplanted from, say, France's Bordeaux region and California's Napa Valley to places like England and Montana.
That's not necessarily bad news for wine fanciers, say the scientists who prepared the report. In their view, the whole terroir thing may be overrated.
But ecosystem impacts in the new regions may be seriously negative, especially for water and wildlife.
To produce what is claimed to be "the first global map of future suitability for wine production," just published in the Proceedings of the National Academy of Sciences, the research team began with two widely used two scenarios for global warming over the rest of this century.
The more optimistic imagines that greenhouse-gas concentrations in the atmosphere will continue to rise and then to decline somewhat. The more pessimistic has them rise more sharply and steadily through 2100. (For the technically minded, these scenarios are RCP4.5 and RCP8.5, respectively — two of four Representative Concentration Pathways that will be used in the next assessment of the Intergovernmental Panel on Climate Change; more details here.)
These scenarios were then run through 17 global climate models to see where the right conditions of temperature, moisture and growing-season length for grape-growing might occur at mid-century compared to now. Finally, the degree of consensus among the models was used to predict minimum and maximum declines of suitable territory in today's wine-producing regions.
Bye-bye to Burgundy
Under the more optimistic RCP4.5, areas suitable for viticulture in regions like Napa, Burgundy, Tuscany and much of southern Australia decline by a minimum 19 percent and a maximum 62 percent by the year 2050. Under the harsher RCP8.5, projected losses range from 25 percent to 73 percent.
Lee Hannah, who was lead author on the study, is a senior scientist at Conservation International. Writing in CI's Human Nature blog, he explained the overall trend this way:
Wine suitability is moving toward the poles. In South Africa, Chile and Australia, there is little land left in the direction of the South Pole, and suitable area for vineyards is declining.
In the north, there is a lot of high-latitude land, and area suitable for vineyards is expanding. This will result in a global redistribution of wine-producing regions, with some serious consequences for ecosystems and wildlife habitat.
And a region of Montana just north of Yellowstone National Park is one of the areas where vineyard-suitable land increases most over the next 40 years, according to data assembled by Hannah and co-authors.
It's also smack in the middle of a wildlife corridor that conservationists consider as essential habitat and escape route for wildlife adapting to climate change.
This shift may have a big conservation impact on the Yellowstone to Yukon Conservation Initiative (Y2Y), an innovative attempt to connect wildlife habitats between Yellowstone and Canada’s Yukon Territory. Vineyards would be a major impediment to this connectivity. They provide poor habitat for wildlife, and would probably have to be fenced to avoid bears snacking on the grapes.
We may think of vineyards as fairly benign in terms of environmental impact, especially when compared to industrial-scale farming of row crops. They're just so pretty.
Grape-growing's big footprint
But they also use a lot of water, not just for plant growth but for frost protection. They can require significant loads of fertilizer, natural or synthetic, and of pesticides. All of these requirements are likely to be higher, not lower, as growers work establish vineyards in new regions.
I can hear some of you saying, enough about the environment already — what will Montana wine be like?
Hannah thinks it will be just fine, and points us to an amusing recent exercise in blind taste-testing called "The Judgment of Princeton."
Wine fanciers will recognize the joke there. In 1976, in an event that came to be known as "The Judgment of Paris," French judges did a blind test of France's top vintages against some interlopers from California. The American wines' sweeping triumph put Napa on the map.
Last June a similar judging was held in Princeton, N.J., where the American Association of Wine Economists was having its annual conference. And while the results were not as clear or compelling as those from Paris, some of New Jersey's young wineries did pretty well.
Perhaps a nice Chinese red?
Hannah's point being, if New Jersey's wines can get some respect from the experts, why couldn't Montana's? Or, for that matter, China's?
Believe it or not, China is the fastest growing wine-producing region in the world. By aggressively buying both wine and vineyards, the country’s upper classes are driving up the price of both. As this upper-class fervor for wine reaches the middle class in China, demand will explode.
Much of that demand will be met by imports, but China has suitable areas for growing wine grapes, and production will start there as well. Those areas happen to be in the same mountains that are habitat for giant pandas, so wine expansion in China may have repercussions for what is arguably the world’s most iconic animal.
Curious to know what people in the wine world might think of all this, I ambled over to the Wine Spectator and found senior editor Dana Nigro's post in the Mixed Case blog. She treated the research with considerable respect, while rebutting the notion that migrating wine producers will necessarily become destructive invaders. Some may even stay put:
Grape growers have other alternatives to moving into wild lands, such as planting new or different grape varieties better suited to expected climate conditions, though selling Grenache from Burgundy or Napa Mourvedré presents marketing challenges.
Vineyard management techniques can limit sun exposure and keep clusters cooler. New winery practices are dramatically reducing water use.
And I thought she underscored the study's broader point quite generously, too:
This isn't just about wine. Grapes serve as a bellwether for all sorts of crops, from coffee and cacao to corn, rice and wheat.
Why? Wine grapes — think about all the focus on terroirs — are sensitive to shifts in temperature and moisture. Many vineyards are located in areas with Mediterranean climates, which also happen to have high levels of biodiversity but have already lost a lot of habitat.
Hillsides are prime sites for vines, and as temperatures get warmer, the inclination may be to move further upslope — to wildlife areas — to find cooler conditions. Plus, many vineyards aren't irrigated, so could be more susceptible to heat and drought.
"We really think this kind of study should be done crop after crop" to understand farmers' need to adapt, said co-author Rebecca Shaw, climate scientist and associate vice president at Environmental Defense Fund.