Opinion

There was a time when exceptionally warm and dry years produced excellent vintages of wine. The warm and moderately dry summers favored a complete and balanced ripening of the grapes. On the other hand, in colder and rainy years, the grapes did not ripen properly, and farmers could be forced to harvest early to avoid the development of fungus in the bunches. Higher temperatures combined with periods of more intense summer drought have favored the production of high quality vintages. in appellations around the world. Nowadays, it is rare to find summers that are not dry and warm enough, but we are beginning to feel the impact of extreme episodes of heat and drought, to the point where vines in some regions of Spain are dying due to high temperatures and lack of water.

Climate change, a threat to wine typicity
Wines are the result ofterroir, a combination of the characteristics of the soil, the plant, cultivation techniques and climate. The terroir affects the development of the vine and the composition of the grapes, so that each wine-growing region produces wines with clearly identifiable characteristics, which define their quality and style, that is, their typicity. This typicity is what makes a wine recognizable throughout the world. However, with climate change, the climatic variable in this equation is changing at a rapid pace, making it increasingly difficult to maintain this typicity. Over the last 40 years, there has been a progressive advancement of harvest dates in most of the world's wine regions and grape ripening takes place during the hottest part of the summer, thus under more extreme environmental conditions. As a consequence, fresh and floral aromas are replaced by profiles more similar to cooked fruit. Acidity decreases in favor of sugar accumulation, resulting in wines that are less fresh, with higher alcohol content and, in the case of red wines, a more subdued color.

Transition to irrigated viticulture
If CO2 emissions are not drastically reduced, temperatures are expected to continue to rise in the coming decades and heat waves will become more frequent and intense. Under these conditions, even if rainfall is maintained, which seems unlikely, crop water consumption will be significantly higher. In the Mediterranean area, vines have historically been grown without water input. However, climatic conditions are leading some countries, such as Spain, to start implementing irrigation in this crop. Even guaranteeing a rational and efficient use of water, the increase in the irrigated vineyard area will contribute to increasing the pressure on this limited resource, and the vine will enter into competition with other crops that are essential to guarantee food security.

Adapting to a warmer and drier future
Adaptation to climate change is one of the main challenges facing the wine industry in the coming years. Short-term adaptation strategies, in addition to irrigation, include the use of new viticulture techniques, such as plant covers, shading nets, or different vegetation management systems, among others. In the longer term, there is the possibility of changes in varieties/clones or rootstocks with later ripening or greater tolerance to drought. However, there is a point of no return where the migration of vines to higher latitudes and altitudes is contemplated. At the Institute of Biodiversity and Environment BIOMA of the University of Navarra, we investigate the response of different varieties and rootstocks to climate change (RIZHOCLIMAVID¹ and CARVITRANS² projects) or more novel strategies such as the application of ripening modulators (CLIMAVITIS³ project) or the use of beneficial microorganisms present in the soil. 

The world is changing and so are consumer preferences. There are ways to adapt and mitigate certain aspects of climate change. However, it is to be expected that, as a result of climate change or as a consequence of adaptation measures, the typicity of our wines will be affected to some extent forever.

_{1 R&D&I project / PID2020-118337RB-I00 funded by MICIN/AEI/10.13039/501100011033.
2 R+D+i Project / PID2023-151816OA-I00 financed by MICIU/AEI/10.13039/501100011033 (10/24/24/24 in proposal of final resolution).
3 Project within the framework of the Program for the promotion of collaboration in R&D&I actions between Autonomous Communities. Funded by the Recovery, Transformation and Resilience Plan, the European Union-NextGeneration EU, MICIN and the Government of Navarra. Managed by the Eatex Food Innovation Hub.}