The geography of wine is changing and will change much more in the coming years in up to 70% of the current growing and production areas due to the effects that increased temperatures and altered rainfall have on grape yields. its composition at the time of harvest and the quality of the resulting wine. This is the main conclusion of a new study on the impact of climate change on global viticulture carried out by researchers from the universities of Bordeaux (France) and Palermo (Italy).
In the event that temperatures rise by more than 2ºC, "90% of the traditional coastal and lowland wine regions of Spain, Italy, Greece and Southern California could face a major loss of suitability [ making the production of premium wine impossible] by the end of this century due to excessive drought and more frequent heat waves," warn the authors of this study.
In the section on regions potentially benefiting from the new climatic conditions, the authors point out that "between 11% and 25% of existing wine regions could experience increased production; such as the states of Washington and Oregon (in the United States), Tasmania or northern France." In addition, "new suitable areas could emerge at higher latitudes and altitudes, for example the south of the United Kingdom," depending, however, on the level of temperature rise, the authors note.
The effects of global warming on the wine sector have been studied for years and in some cases adaptations of crops to new conditions are already being applied. The work now presented, published (March 26) in the journal Nature Reviews Earth
Furthermore, the team behind this study, led by Cornelis van Leeuwen, professor of viticulture and head of department at Bordeaux Sciences Agro, also points out the areas of the planet in which, due to new climatic conditions, viticulture could expand and proposes detailed monitoring of "the impacts on natural ecosystems and biodiversity in order to mitigate any negative impacts."
The new study devotes much of its analysis to current and future conditions in Europe.
The combination of rising temperatures and reduced rainfall will cause a serious risk of drought in the south of the Iberian Peninsula, southern France, Mediterranean Spain, the Po Valley and the northern coast of Italy, the Balkans and the southwestern Black Sea. details the study. In these areas, heat waves and water scarcity "could make any extensive project unsustainable, increasing the risk of crops losing suitability, that is, not being able to produce high-quality wine."
Furthermore, warmer conditions and greater exposure to solar radiation (burns to leaves and vine) negatively affect both the yield and quality of the wine in these areas. "Under severe warming scenarios [more than 2°C rise], most Mediterranean regions below 45°N could become climatically unsuitable for wine and vineyard production, and the only alternative in these areas would be vineyards at higher altitudes. The authors calculate, however, that "only a small portion of this loss (less than 20%) can potentially be compensated by the displacement of vineyards towards mountainous areas."
Also for severe warming scenarios, the authors indicate that "a transition to later-ripening grape varieties is likely to be necessary in these regions." In contrast, Galicia, the northern Balkans and, in general, areas above 46° N are expected to benefit from warming, at least for limited levels of temperature increase. Also consider that, in some of these cases, early sprouting could increase the risk of spring frosts.
Across Europe as a whole, new wine regions are expected to expand northwards, especially along the Atlantic sector, resulting in a net increase of climatically suitable areas in Europe by up to 60%. Although, as the authors acknowledge, this expansion is purely theoretical and refers only to climatic conditions, without considering soil quality, pre-existing land use and other factors crucial for the establishment of new vineyards.
Putting the new study in context, Javier Martín-Vide, climatologist and professor of Physical Geography at the University of Barcelona [an expert who has not participated in the preparation of the new study but is familiar with its results], remembers that "the increase in the temperature of the The air in the Mediterranean basin has already reached 1.5ºC compared to the average temperature of the second half of the 19th century, while at a global level it is at 1.2ºC, making the basin a hot spot, a region especially sensitive to warming.
Regarding the data now presented, Martín-Vide tells La Vanguardia that "undoubtedly, warming will affect the cultivation of vines, like other crops, especially, as the article cites, due to the negative impact of heat waves." ", increasingly more frequent, intense and lasting, and due to droughts, increasing".
Rafael Andrés Peinado Amores, professor of the Department of Agricultural Chemistry, Soil Science and Microbiology at the University of Córdoba; and Fernando Sánchez Suárez, agronomist and oenologist, predoctoral researcher at the Department of Agricultural Chemistry, Soil Science and Microbiology at the University of Córdoba, consider that "the article [now published] provides a thorough review of the changes that, in production and quality of wines, are already occurring due to the effect of climate change", Among the aspects to take into account, these researchers point out, in statements collected by SMC, that the new study "highlights the pressure of pests and diseases in these possible new conditions, where fungi that need greater humidity to develop will see their progress slowed in contrast to others in drier weather."
Javier Martín-Vide points out that, "it must be noted that the new study does not sufficiently emphasize the great plasticity of this crop."
"The vine, with its multiple varieties, appears in the case of Spain in all its regions, with climates as contrasting as the Atlantic, and thus there are famous vineyards and designations of origin in Galicia or the Basque Country, with average annual rainfall that exceed 1,500 mm, and others in the southeast of the peninsula, in Murcia, in a climate of notable aridity, with average annual rainfall of less than 300 mm, not to mention Lanzarote, where vines are also grown, with an average annual rainfall that is barely reaches a hundred millimeters," explains Martí-Vide. "In terms of temperature, the contrasts are also very marked, with some of the most famous vineyards in the world in Castilla y León, which sometimes reach minimum temperatures of -10 ºC, and even less, and others also renowned in the south of the peninsula, in some regions where frost is almost unknown, or in the Canary Islands itself.
Collecting some of the proposals of the new study, Martín-Vide considers that "it is evident that it will be necessary to adapt to the new scenarios that, in Spain, coincide in a clear thermal increase and a tendency to reduce rainfall, cultivating the best species adapted to increasing thermal and water stress, varying cultivation techniques, etc. "In some cases, later in the century and if things do not change much, perhaps some traditional wine regions will have to be abandoned, to gain altitude, as certain Spanish and Catalan wineries are already doing, exemplarily. In this regard, the majority of winegrowers Spaniards have great knowledge about this new reality".
Finally, the vine, like other crops, suffers, especially when what have recently been called compound hot-dry events occur, that is, the coincidence in time of heat waves during periods of drought, as has happened in Spain in recent summers. "The negative impacts on agriculture of this climate risk are more harmful than the sum of the negative effects of heat waves and droughts when they do not coincide in time. We will have to be prepared for the foreseeable increase in these compound hot and dry episodes" , concludes Javier Martín-Vide.
