Vine culture faces the challenge of climate change

Will changement climatique finally benefit the wines of Bourgogne? Complex question. Because the danger of warming remains bien present, forcing the vignerons to adapt.

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Droughts, water shortages, forest fires… The consequences of changement climatique are undeniable. Even in Bourgogne-Franche-Comté, the summer of 2022 has been particularly rough, with for example important fires in the Jura, or even in Selongey in the Côte-d’Or. And restrictions on the use of water generalized in all the departments of the region.

Nos vignobles peuvent-ils faire figure d’exception? These special climatic conditions have in effect allowed the Burgundian vignerons to harvest quality grapes this year, the 2022 vintage is also announced by the BIVB (Bureau Interprofessionnel des Vins de Bourgogne) as one of the vintages of the century.

► À lire aussi: Vins: vers des excellents millésimes 2022 pour les Chablis et Irancy?

The vineyards of the northern regions, such as those of Bourgogne, are clearly the winners of changement climatique“, analyzes Benjamin Bois, maître de conférence en viticulture et climatologie à l’université de Bourgogne. “For the moment, there are more good years in the region than bad years, in terms of quality.

No serious damage… mais des damage malgré tout

Even if they have the exception rather than the rule, damage has been noted in certain burgundy parcels this year. Notably in the youngest vines, where the roots were not sufficiently deep. “Là, elles ont subi un peu trop dument le stress hydrique (le manque d’eau, ndlr)“, explains Benjamin Bois.

The last notable episode of disasters in the cultures dates back to the last one, when a frost episode devastated the vines in several departments of Bourgogne. “Cet épisode était, sur le principe, une gelée typique ‘climate change'”, détaille le chercheur. “C’est-à-dire that it was so hot at the end of winter that the buds came out too early, and the vine exposed the vine too early.

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Could such episodes be repeated in the future? Difficile à affirmer avec certitude pour le moment. “These jellies don’t go in the sense of what the climate models tell us“, précis l’universitaire. “So the scientific and climatological community scrutinizes them with attention and circumspection. Pour l’instant, on ne sait pas trop.“Mais comme il n’y a pas de mal don il ne naisse un bien, ce passage de froid est en partie à remercier pour l’excellent millésime 2022 qui se profile.”Après une année gélive, souvent, la vigne reagit par une belle sortie de grappés. As was the case, for example, in 1992, after the frosts of 1991.

S’ils ne sont pas les plus touchés le changement climatique, the Burgundian vineyards are ne sont toutefois pas à l’abri de mutations more or less profound in the years or decades to come. In the short term, the increase in temperature should increase the sugar content of the raisins, and therefore the potential alcohol, and lead to a decrease in their acidity. “If one wants to be alarmist, one can say that the wines of Bourgogne as they are today will no longer exist in 2050 or 2060“, advanced Benjamin Bois. “It is almost impossible to maintain the typicality of the wines, because there is already a deep layer called climate warming that makes it inevitably evolve.

The taste and flavor profile of today’s wines is not the same as that of wines from the same Bourgogne, from the same grands crus, from the 1970s or 1980s.

Benjamin Bois, maître de conférence en viticulture et climatologie à l’université de Bourgogne

A phenomenon that is not new… not only is it limited to the Bourgogne region. “It is valid in all regions of the world. Il faut être honnête : the taste of wines changes little by little“, assure the researcher. Pour autant, il se dit optimiste quant à capacité des vignerons Bourguignon à continura produire des wines de grande qualité.”On n’est pas en Espagne, où le dérèglement climatique begins à realmente poser problème“, glisse-t-il.

► Also read: Réchauffement climatique en Bourgogne-Franche-Comté : “des incendi de forêts ici, ce nest que le début” alerte un scientifique

Because of the strong heat, many producers of the Iberian peninsula are in effect forced to irrigate their plots in order to continue producing. According to the Spanish Ministry of Agriculture, more than 400,000 hectares of vineyards, or approximately 41% of the total vineyard surface, were irrigated in the country in the summer of 2021.

There is a real dichotomy between the vineyards of cold climate and those of warm climate, as in the south or in Spain for example“, details Benjamin Bois. “Ceux-ci n’ont pas necessarily été advantaged par des degrés en plus.“Des degrés en plus qui should, sur le long terme, également poser problème aux travailleurs de la vigne dans région.”On risque d’avoir des phénomènes de brûleres sur raisin, pour travailar dans les vines, il faudra se lever très early le matin…“, énumère l’universitaire.

Le personnel dans les vignes pose déjà problème aujourd’hui. The management of the main-d’œuvre risque de ne pas s-arranger.

Benjamin Bois, maître de conférence en viticulture et climatologie à l’université de Bourgogne

► À lire aussi : Vendanges : face à la pénurie de main d’œuvre en Bourgogne, des solutions exist

Like other plants, the vine, or vitis vinifera as it is called scientifically, is a species within which there are many varieties. In Bourgogne, we mainly find pinot noir and chardonnay, respectively for red and white wines. “These grape varieties are not as varied as in other regions, in Bordeaux for example, where there is a real culture of mixing different grape varieties.“, notes Benjamin Bois.

In these sectors, many vinticulturists choose to gradually replace the less resistant varieties with more resistant varieties. This is the case, for example, of the famous Cabernet Sauvignon, the second red grape variety in terms of surface area in Bordelais. “Dans les années 70, les mauvaises langues disaient quil murissait bien une année sur 10“, s’amuse le chercheur.”Aujourd’hui, on voit that it is more and more cultivated because it is found both in a warmer climate.

30 years ago in Bourgogne, it was pinot noir and today, it is pinot noir.

Benjamin Bois, maître de conférence en viticulture et climatologie à l’université de Bourgogne

The solution would therefore be the change of current cultivars for others, more adapted to high temperatures? Cela pourrait l’être… au risque de produire des vins totally differents qui n’auraient plus de Bourgogne que le nom. “Il ne faut pas se leurrer: changing the grape variety is not the solution that will allow us to maintain the same quality of wines, with the same profile aromatic”, argue l’universitaire “Peut-être qu’on arrivera à faire de très grands vins sur le même territoire, mais ce ne sera plus la même thing et le consommateur risque d’être perdu.

► Also read: Les climats du vignoble de Bourgogne célèbrent leurs seven ans au patrimoine mondial de l’UNESCO

It’s better to prevent than to cure and the Bourguignon winegrowers have understood this. In order to protect against the inevitable rise in temperatures, the association technique viticole de Bourgogne (ATVB) has put in place “conservatories”, including one in the Dijon suburb. Pinot noirs and chardonnays are grown, with the aim of studying their behavior in the local climate.

Le cépage n’est pas juste un être vivant qu’on clone et qu’on multiplie“, said Benjamin Bois. “As in a family, the genome varies. Il n’y a pas un pinot noir, mais Dec pinot noirs Certains font des gros raisins, d’autres petits raisins, et d’autres supportent mieux les coups de chaud. C’est pour trouver ces ‘clones’ qu’ils sont etudiés.

The other “boîte à tools” that vinticulturists have is the porte-graffe, that is, the root part on which the vine is grafted. Amené in France at the end of the 19ème siècle to respond to phylloxéra, a parasite that devastated a part of the French vineyard, the porte-graffe also has many variations. Some, more adapted to dry climates, represent an ally of choice in adapting to climate change.

Dans un entretien accordé au Figaro (paid article) on September 13 last, the Minister of Agriculture Marc Fesneau estimated that the products benefiting from appellations d’origine contrôlées (AOC) allaient “should probably rethink” their charge sheet, for better respond to the problem of climate warming.

A solution that might be of interest, according to Benjamin Bois. “The cahier des charges borne the choix du cépage, but also the way the vines are cultivated in Bourgogne“, expose-t-il. “Dans la region, on cultive les vignes à haute densità. Les vignes sont espacées d’un mètre, en rang assez bas. But in fact, plus on est proche du sol, plus il fait chaud le jour et froid la nuit.” Making the vines taller and more airy will allow me to reduce the number of leaves per hectare, which will delay the ripening of the grapes.”But airing the vines, it is impossible with a cahier des charges that imposes the vines at high density“, concluded.

As a reminder, Bourgogne has no less than six AOCs in terms of wines, spread over more than 250 square kilometers.

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