The concept of geographical indication (GI) plays an essential role in defining a wine’s identity and establishing a strong link between the product’s unique characteristics and its provenance1. Indeed, many of the world’s most famous wines are known for their origin and not for their grape variety2. The system of classifying and regulating wines based on their origin is commonly referred to as Geographical Indication or appellation3 and the strictest rules can be found in Europe, where premium GI wines are labelled as Protected Designation of Origin (PDO)4. These wines can only be produced in legally defined areas that have been selected based on soil type, climate, and historical or administrative divisions. The presence of both human and natural dimensions in defining wine regulations is related to the historic concept of Terroir: an originally French notion that states that the place (both the land and the people) define the product5.
Climate change is increasingly impacting several aspects of viticulture, including vine phenology6–8, grape composition9–11 and growing suitability12–14. These bio-physical changes require growers and producers to adapt by employing new cultivation techniques, using new varieties, or shifting cultivation locations15–18. However, the legal rigidity of the GI system significantly impairs the ability of many wine regions to adapt and to preserve traditional wine production in the context of climate change, i.e., GI resilience. For example, Burgundy and Champagne are known for wines made from Pinot Noir. If these regions become unable to grow typical Pinot Noir grapes at some point, they are under serious threat. A substitute grape candidate would neither qualify for the label, nor would the law permit growers to source grapes from outside the region or introduce new cultivation techniques19,20 without going through a tedious process of amending the wine region’s regulations21. In many wine regions, increasing resilience will therefore depend upon adaptation strategies that overcome traditional and legislated practices by including more flexibility to better support the sustainable development of wine making in uncertain climates.
Assessing the vulnerability of wine GIs to climate change facilitates the understanding of which regions are threatened the most by climate change and supports the development of potential adaptation pathways to strengthen their resilience. The vulnerability depends on the individual characteristics of each wine region, including the degree of climate exposure and sensitivity and the availability of socioeconomic, natural, and physical resources, which strongly determine how wine appellations can adapt to climate change22. The importance of exposure and sensitivity has already been extensively investigated, for instance by relating changes in air temperature or precipitation to relevant vine parameters7,13, 23–25, or analyzing how grapevine diversity and variety turnover influence future land suitability26–28. However, assessments that consider the adaptive capacity and vulnerability levels of wine appellations have been sparse and thus far, limited to single wine regions29–33. The consideration of these characteristics is especially critical for regions that face strong impacts of climate change and need to amend their legal specifications to continue producing GI wines, which requires extensive access to resources and knowledge and may thus not be feasible for appellations with a limited adaptive capacity30,34. The future of the GI system under climate change is therefore still poorly understood and our knowledge of how adaptive capacity and climate change vulnerability are related to the resilience of wine GIs is very limited.
In this study, we assessed the climate change vulnerability of 1174 wine regions in Europe by explicitly considering their biophysical and socioeconomic characteristics and their regulatory specifications. We used a novel dataset on European wine appellations35 coupled with an index-based approach including an ensemble of financial, natural, physical, and social indicators. To assess the climate change vulnerability, we adapted the framework developed by the Intergovernmental Panel on Climate Change (IPCC) in which vulnerability is assessed as a function of exposure, sensitivity, and adaptive capacity. We defined (i) exposure as the expected changes in climatic conditions, including temperature and precipitation, (ii) sensitivity as the degree to which a system is affected by climate related stimuli, based on the biogeographical niche of each wine region, and (iii) adaptive capacity as how well a wine region can adapt to changing climate conditions, considering five distinct dimensions (financial, natural, physical, social, and human) (see Methods). We used a comparative analysis that provides a basis for adaptation planning at different spatial scales, from the European to the national and regional scales, and allowed us to identify potential future pathways related to the climate resilience of the GI system. As such, the results will be valuable to international entities as well as regional decision-makers and represent a first step in evaluating the consequences of climate change for designated appellations across Europe. The results will also be particularly useful to identify priority areas with urgent needs for adaptation and further in-depth studies.
Exposure and sensitivity to climate change
Climate variability has always affected winemaking, but the current rate of climate change is unprecedented, challenging the historical union between favorable site conditions, optimum grape varieties and traditional viticultural practices. We defined exposure as the degree to which climate is projected to change in wine regions. The highest levels of exposure were observed in Slovenia, followed by Croatia, Italy, Greece, and Spain with 29%, 27%, 6%, 6% and 3% of wine regions with an exposure level in the upper percentile, respectively (Fig. 1a). Many of these regions are located in mountain terrain, especially in the Apennines, Alps and Carpathian Mountains. In contrast, exposure levels were lower in Portugal and France, where less than 5% of the wine regions had an exposure level over 0.85. Low levels of exposure were also found in Germany, Belgium, and the Netherlands with an average exposure level below 0.3. While there is a trend towards increased temperatures in most regions, precipitation trends are mixed with a tendency towards less precipitation (Fig. 1c). The observed trends are consistent with other studies that use the CMIP-6 scenarios36,37. Our results are also in-line with studies analysing climate change impacts on European viticulture, many of which observed high levels of impacts in areas that correspond to high-exposure regions in our study. For instance, strong yield decreases were projected for northern Italy, central Spain, Greece, and Bulgaria7 and decreased suitability for Spain, parts of France, central and northern Italy, and large parts of eastern Europe23.
Climate change is also altering the traditional identity of GIs by moving wine regions either closer to their climate optimum or pushing them further away. As such, the sensitivity level describes the degree to which a system is affected by climate related stimuli based on the climate niche of currently cultivated varieties. We found that regions in southern Europe often tended to have higher sensitivity levels either due to a limited grape variety spectrum or due to warm climatic conditions close to the upper limit of their niche (Fig. 1b). However, we also found regions with low sensitivity levels in Southern Europe, e.g., Do Tejo (PT), and regions with increased sensitivity at higher latitudes, e.g., Champagne (FR). Higher sensitivity was often observed in specialized wine regions where only few varieties adapted to local climate conditions are cultivated, while regions with a wider range of varieties tended to have lower sensitivity levels (Fig. 1d). Although we calculated the sensitivity based on a detailed database of authorized varieties for each GI, more information about local vine cultivars, especially their climate niche and phenological development, would improve assessments of changes in growing suitability and climate change sensitivity. However, such detailed knowledge is mostly limited to international varieties, which only include approximately 1% of global vine diversity, reducing our capacity to estimate future impacts of climate change in GIs26. If climate change is to proceed at the current rate, the GIs as we know them now will necessarily change because the best location for a given variety today might be the best location for a different variety in the future38. The diversity of cultivated varieties will therefore be a critical factor determining the magnitude of future impacts26. Specifically, regions with a high sensitivity should work towards increasing the diversity of cultivated varieties to reduce their vulnerability to climate change.
Adaptive capacity to climate change
To adapt and cope with climate change and compensate for high exposure or sensitivity levels, GI regions need access to resources which enable and facilitate the execution of adaptation strategies. We therefore considered 15 indicators of adaptive capacity (Table 1) to analyse the potential of wine regions to adjust to climate change, i.e., their adaptive capacity.
Table 1 Indicators of adaptive capacity.
Dimension
|
Indicator
|
Description
|
Social
|
Aging index
|
Ratio between old and young population
|
Dependency ratio
|
Ratio between dependent and working population
|
Population density
|
Population density per agricultural area
|
Physical
|
Road length
|
Total length of roads potentially usable for viticulture
|
Mechanization Index
|
Value of machinery & equipment of wine farms
|
Naturalness
|
Share of natural and semi-natural areas in winegrowing areas
|
Natural
|
Shift in Space
|
Available areas with cooler climatic conditions suitable for viticulture
|
Water availability
|
Excess precipitation available in winegrowing areas
|
Temperature variability
|
Variability of mean temperature
|
Human
|
Labour force
|
Ratio between regular and total farm labour force
|
Education Level
|
Education level of farm managers
|
Research accessibility
|
Proximity to closest research centre on wine and vine
|
Financial
|
Debt ratio
|
Liability percentage of total assets of wine farms
|
Return on assets
|
Profitability in relation to total assets of wine farms
|
Subsidy dependence
|
Net income percentage coming from subsidies of wine farms
|
Some European wine regions with the highest adaptive capacity were found within or near the European Alps and along the Apennines (i.e., on the west coast of the Italian peninsula) (Fig. 2a), for example, Conegliano Valdobbiadene Prosecco (IT) and Alto Adige (IT) (Fig. 2c). Slovenia and Italy were the countries with the highest share of regions with an adaptive capacity level in the upper quartile (65% and 14%, respectively), followed by France with less than 10%. In contrast, regions in central Spain and eastern Europe such as Slovakia, Greece, Romania, Bulgaria, and Hungary, had low adaptive capacity levels with average values below 0.3. The regions in Spain tended to have a high financial capacity; however, they had low scores for all the other dimensions, especially the physical and natural capacity, resulting in a low overall adaptive capacity (e.g., La Mancha (Fig. 2c)). Winegrowing regions at higher latitudes, including some regions in France, Germany, Denmark, Belgium, or the Netherlands, mostly had moderate adaptive capacity levels around 0.5 (e.g., Rheinhessen (DE) and Alsace (FR) (Fig. 2c)). These differences in adaptive capacity across wine GIs in Europe strongly determine how individual regions can adapt to climate change34. However, despite the growing evidence that the adaptive capacity plays a central role for future climate change impacts39,40, regional viticulture-specific data are not available on a European scale for many dimensions of adaptive capacity. The focus of previous studies on climate change adaptation in viticulture and agriculture in general was primarily on bioclimatic pressures, while the social part has often been neglected41. Future climate change adaptation and our understanding of the climate change vulnerability of wine regions could therefore benefit extensively if studies accounted for differences in adaptive capacity, especially regarding their socioeconomic characteristics42.
Pathways to climate-resilient wine growing
The development of a climate-resilient wine sector requires the consideration of all factors that determine vulnerability to climate change, i.e., exposure, sensitivity, and adaptive capacity (Fig. 3). This will be important to identify sound adaptation options and increase the resilience of the GI system. Based on a cluster analysis of the characteristics of individual wine regions, three possible pathways for dealing with climate change emerged.
The first development pathway concerns highly vulnerable wine regions that are likely to face strong changes within the next few decades (cluster 6 (Fig. 3b)). If these regions are to continue the production of GI wines, they will need to act fast and employ adaptation measures that go beyond vineyard management strategies and include grape diversification (i.e., new varieties) or site relocation (i.e., new climates)17. The most prominent examples of this group of regions can be found in the Iberian Peninsula (e.g., Douro (PT), Rioja (ES)), southern France (e.g., Côtes de Provence), Greece (e.g., Samos) and Bulgaria (e.g., Southern Black Sea coast). Previous studies already highlighted significant changes in growing suitability due to climate change expected in many of these regions7,13,23,43. Because the scope of the required adaptation measures often entails a partial or complete departure from traditional appellation regulations, early warning and awareness is critical to successful implementation and to providing the necessary support to prepare eventual amendments to production regulations.
The second pathway represents regions with a moderate vulnerability level which are better prepared to face the adverse effects of climate change compared to regions in cluster 6 and belong to cluster 4 and 5. Some of these regions were located in southeast France (e.g., Roussette de Savoie), northern Italy (e.g., Conegliano Valdobbiadene Prosecco), Slovakia (e.g., East Slovak), the Iberian Peninsula (e.g., La Mancha (ES)), Romania (e.g., Cotnari), Bulgaria (e.g., Varna) and in the Apennines. These regions are faced with high exposure and moderate to high sensitivity levels and feasible adaptation strategies will strongly depend on their adaptive capacity. For instance, strategies such as shifting vineyards to higher elevations or exploiting favourable microclimatic niches can be a very effective measure in mountain viticultural areas but may not be geographically possible in other regions44. Likewise, expanding the possibility for irrigation can be a promising option, but the high economic burden, intensive labour cost, water, and mechanization requirements, and legal constraints make this option feasible only for a limited number of regions with sufficient socio-economic resources25. Many regions with a low adaptive capacity, which is especially the case in cluster 5, will therefore likely require resources and external investments to increase their potential for adaptation.
The third pathway describes a scenario for regions with the lowest vulnerability levels representing clusters 1, 2 and 3. These regions generally have moderate to high adaptive capacity levels combined with either low sensitivity or low exposure levels. This gives them the best prospects of maintaining their historic identity and high production standards in the medium to long term. These clusters include some regions at higher latitudes (e.g., Rheinhessen (DE) and Crémant de Wallonie (BE)), in France (e.g., Côtes d'Auvergne, Bordeaux, and Alsace), Czechia (e.g., Moravia), or the European Alps (e.g., Alto Adige (IT)). Because many of these regions have extensive access to resources, including natural, physical, or economic assets as well as necessary knowledge and the appropriate labour force, they have the greatest possibility of implementing and elaborating costly adaptation strategies that would not be feasible in other regions. Although some of these regions are faced with significant changes in climate or have a high sensitivity, their high adaptive capacity makes them less vulnerable to such adverse effects. For instance, in the case of high exposure levels, adjustment of viticultural processes, such as canopy management or pruning techniques, could facilitate adaptation16. In the case of high sensitivity levels, innovation regarding new varieties and blend compositions or ratios could be promising options26,38. Gradually introducing new varieties and adjusting wine blends might provide an opportunity for these regions to slowly prepare consumers and alleviate concerns about consumer expectations, as is currently occurring for example in the region of Bordeaux45.