Claim: Global warming pushes wines into uncharted terroir

” “Some people may still be skeptical about global warming, but not anyone in the wine industry.”

The media release is below.


Global warming pushes wines into uncharted terroir
Heat has decoupled French grapes from old weather patterns


Many factors go into making good wine: grape variety, harvesting practices, a vineyard’s slope and aspect, soil, climate and so on–that unique combination that adds up to a wine’s terroir. Year-to-year weather also matters greatly. In much of France and Switzerland, the best years are traditionally those with abundant spring rains followed by an exceptionally hot summer and late-season drought. This drives vines to put forth robust, fast-maturing fruit, and brings an early harvest. Now, a study out this week in the journal Nature Climate Change shows that warming climate has largely removed the drought factor from the centuries-old early-harvest equation. It is only the latest symptom that global warming is affecting biological systems and agriculture.

Temperature is the main driver of grape-harvest timing, and in the last 30 years, progressive warming has pushed harvest dates dramatically forward across the globe, from California to Australia, South America and Europe. In France, where records go back centuries, since 1980 harvest dates have advanced two weeks over the 400-year mean. These earlier harvests have meant some very good years. But existing studies suggest that regions here and elsewhere will eventually become too hot for traditionally grown grapes. Vineyards may then have to switch to hotter-climate varieties, change long-established methods, move or go out of business. The earth is shifting, and terroirs with it.

In the new study, scientists analyzed 20th and 21st-century weather data, premodern reconstructions of temperature, precipitation and soil moisture, and vineyard records and going back to 1600. They showed that in the relatively cool winemaking areas of France and Switzerland, early harvests have always required both above-average air temperatures and late-season drought. The reason, they say: in the past, droughts helped heighten temperature just enough to pass the early-harvest threshold. Basic physics is at work: normally, daily evaporation of moisture from soil cools earth’s surface. If drought makes soils dryer, there will be less evaporation–and thus the surface will get hotter. The authors say that up to the 1980s, the climate was such that without the extra kick of heat added by droughts, vineyards could not get quite hot enough for an early harvest. That has now changed; the study found that since then, overall warming alone has pushed summer temperatures over the threshold without the aid of drought. On the whole, France warmed about 1.5 degrees Celsius (2.7 Fahrenheit) during the 20th century, and the upward climb has continued.

“Now, it’s become so warm thanks to climate change, grape growers don’t need drought to get these very warm temperatures,” said lead author Benjamin Cook, a climate scientist at Columbia University’s Lamont-Doherty Earth Observatory and NASA’s Goddard Institute for Space Studies. “After 1980, the drought signal effectively disappears. That means there’s been a fundamental shift in the large-scale climate under which other, local factors operate.”

The regions affected include familiar names: among them, Alsace, Champagne, Burgundy, Languedoc. These areas grow Pinot Noirs, Chardonnays and other fairly cool-weather varieties that thrive within specific climate niches, and turn out exceptionally after an early harvest. Study coauthor Elizabeth Wolkovich, an ecologist at Harvard University, said that the switch has not hurt the wine industry yet. “So far, a good year is a hot year,” she said. However, she pointed out that the earliest French harvest ever recorded–2003, when a deadly heat wave hit Europe and grapes were picked a full month ahead of the once-usual time — did not produce particularly exceptional wines. “That may be a good indicator of where we’re headed,” she said. “If we keep pushing the heat up, vineyards can’t maintain that forever.”

Across the world, scientists have found that each degree Centigrade (1.8 degrees Fahrenheit) of warming pushes grape harvests forward roughly six or seven days. With this effect projected to continue, a 2011 study by Lamont-Doherty climate scientist Yves Tourre suggests that a combination of natural climate variability and human-induced warming could force finicky Pinot Noir grapes completely out of many parts of Burgundy. Other reports say Bordeaux could lose its Cabernets and Merlots. A widely cited though controversial 2013 study projects that by 2050, some two-thirds of today’s wine regions may no longer have climates suitable for the grapes they now grow. But other regions might beckon. Grapes no longer viable in California’s Napa Valley may find suitable homes in Washington or British Columbia. Southern England may become the new Champagne; the hills of central China the new Chile. Southern Australia’s big wineries may have to land further south, in Tasmania. “If people are willing to drink Italian varieties grown in France and Pinot Noir from Germany, maybe we can adapt,” said Wolkovich.

However, this begs the question of whether vineyards, or for that matter anything can just be picked up and moved. The earth is increasingly crowded with agriculture and infrastructure, and land may or may not be available for wine grapes. If it is, the soils, slopes and other exact conditions of old vineyards would be difficult or impossible duplicate. And, grape harvests are only one of many biological cycles already being affected by warming climate, with uncertain results. Many insects, plants, and marine creatures are rapidly shifting their ranges poleward. No one yet knows whether many species or entire ecosystems can survive such rapid changes, and the same almost certainly goes for wine grapes.

Liz Thach, a professor of management and wine business at Sonoma State University, said the study is telling growers what they already know. “Some people may still be skeptical about global warming, but not anyone in the wine industry,” she said. “Everyone believes it, because everyone sees it year by year–it’s here, it’s real, it’s not going away.”


6 thoughts on “Claim: Global warming pushes wines into uncharted terroir”

  1. I have a friend that is good at wine making, funny his vineyards were whacked by cold a few years ago. They were devastated, still to cold to raise wine grapes in Northern Minnesota. It may have been possible during the Medieval warming period all though we don’t know the viking that wandered through the area back then did not leave any records, wut we know one thing the arctic was ice free enough that they could make the trip through the arctic into Hudson Bay up the Nelson river to the Red river and its tributaries. Something you cannot do today.

  2. The string of poor harvests in Bordeaux from 2011-2013 was caused by colder than normal temperatures.

  3. OMG – how will we ever adapt to a longer grape growing season?
    What’s that? More wine?

    I’m in.

  4. @David Randall …. agreed. Wine Spectator doesn’t have a single French Médoc bordeaux after 2010 as being exceptional. I’ve looked; I had one of the best bottles of wine – any varietal, any vintage – about a year ago from Trader Joe’s. It was a Château Haut Blaignan from 2010 and I regret I waited so long before sampling it. Needless to say, I’ve been on the hunt for another Médoc like that but to no avail.

    @Duke Silver … I agree, the article made a strong case that this is the best time for wine grape harvests in a long time and then says we’re doomed because late-season droughts are declining. It read more than a little schizophrenic.

    “However, this begs the question of whether vineyards, or for that matter anything can just be picked up and moved. The earth is increasingly crowded with agriculture and infrastructure, and land may or may not be available for wine grapes.”

    I can’t believe this claim was actually made. Do they not know that if not for French varietals having been established in California the terrible disease outbreak decades ago would have forever wiped out all pinot noir and cabernet? Of course you can move vineyards easily; that’s how the wine industry works. Furthermore, wineries typically make use of marginal or otherwise unproductive land. And if the price warrants change, regular rotational and grain crop farmers will carve out swaths of their own land to establish new vineyards.

    This is all much ado about nothing save for fear-mongering amongst ecologically-minded wine snobs.

  5. A similar story to this on the BBC last week citing the growing of vines in Cornwall as proof of climate change. Typically the BBC completely ignored the fact that the Romans had been growing vines in Cornwall 2000 years ago and on south facing slopes as far north as Cumbria.

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