As climate change accelerates, it poses a real and present problem for winegrowers.
Primarily caused by humans, greenhouse gas emissions accumulate in the lowest layer of our atmosphere – called the troposphere – where they trap the heat given off by the Earth, resulting in rising temperatures. These emissions are responsible for what is known as the greenhouse effect in our atmosphere.
The more temperatures rise, the greater the costs of adapting the vineyard to changing atmospheric conditions. In addition, global warming will adversely affect grape quality and redraw the geographical limits of where quality grapes can grow.
Evidence shows that climate change can benefit winegrowers in certain regions, for example by producing riper fruit or opening up new areas for winegrowing, as in the case of England. However, the impact on other, more traditional winegrowing regions such as Spain or France could be detrimental, creating conditions that would pose enormous challenges for growing suitable grapes and producing wine (1).
Certain adaptation strategies focus on grapevine phenology, aimed at implementing viticultural measures which would allow the vineyard to adapt to a gradual rise in temperature.
The growth season of the grapevine depends on temperature, so much so that the development of the individual phenological stages (budbreak, bloom, veraison, and maturation) can be predicted using models exclusively based on temperature (2). One of the direct consequences of global warming is that these stages set in earlier, bringing the harvest forward.
When it comes to ensuring the future of winegrowing in these warm regions, genetic crop diversity is a valuable resource. Planting grapes better adapted to the changing regional climate would allow winegrowers to keep their vineyards in their current location.
A perfect example of this trend is Bodegas Torres, which is experimenting with minority varieties such as Petit Verdot in Catalonia. This particular grape is very interesting from a climate change standpoint, because it is late-ripening and produces high-quality wines.
A study published in Proceedings of the National Academy of Sciences shows how, at the current rate of global warming and in the absence of adaptation measures, 56% of the world’s wine regions may become unsuitable for winegrowing. If winegrowers switched to varieties better suited to a changing climate, however, that loss would drop to 24%.(3)
For example, in the French region of Burgundy, heat-loving varieties like Mourvedre and Grenache could replace current varieties like Pinot Noir.
Likewise, the use of indigenous varieties is an increasingly common adaptation strategy, seeing how these varieties are perfectly acclimated to the particular conditions of the vineyard.
In late 2021, the EU approved the use of vitis vinifera grape varieties, as well as hybrids containing genetic material of vitis vinifera and non vinifera grape species of American and Asian origin, for the production of appellation of origin wines by its member states. This decision came in response to the challenges of climate change and to help the European wine industry become more sustainable.
Drought resistance is another key variable in programmes designed to obtain new varieties for warm regions. The search currently focuses on varieties that need very little water and are better adapted to dryland conditions.
When it comes to adapting the vineyard to changing climate conditions, certain farming practices used in winegrowing can also be quite effective. According to Life Adviclim, cover cropping practices can delay the growth cycle of the vine, especially the start of the ripening process (veraison).
For example, dormant pruning towards the end of winter (closer to budbreak) can delay budding by 8 to 11 days compared to traditional mid-winter pruning.
Likewise, other practices related to soil management, such as superficial tillage, can mitigate drought-related problems by reducing the amount of moisture that evaporates from the soil.
Finally, the choice of rootstock is yet another adaptation strategy that is gaining ground. One of its main advantages is that winegrowers can adapt the vineyard to drought and increased water stress by selecting a rootstock that respects the environment and does not drive up production costs.
Technological initiatives such as those provided by Terraview use machine-learning software to seek real vineyard solutions that will help winegrowers deal with changing climate conditions.
The software uses machine learning and artificial intelligence to collect data such as the hydrological needs of the vineyard, the workforce required for crop management, the impact of diseases and carbon emissions, and then analyses it to provide winegrowers with tangible solutions.
Consumers will also notice the effects of these changing climate conditions in wines with excessively ripe fruit aromas and flavours, less acidity, more sugar, and higher alcohol and pH levels.
Although impacts may vary, the gradual rise in average temperatures is harmful to us all.
Taking steps in terms of climate adaptation is absolutely necessary, but these should be complemented with mitigation and positive impact strategies. It isn’t enough to be “less bad” – we need to start doing things “right” from the very beginning.
Marta Juega, PhD
Works Cited:
1. Schultz, H.R.; Jones, G.V. Climate induced historic and future changes in viticulture. J. Wine Res. 2010, 21, 137–145.
2. Parker, A., García de Cortázar-Atauri, I., van Leeuwen, C. and Chuine, I. 2011. General phenological model to characterise the timing of flowering and véraison of Vitis vinifera L. Aust. J. Grape Wine Res. 17:206–216.
3. Morales-Castilla, I., García de Cortázar-Atauri, I., Cook, B. I., Lacombe, T., Parker, A., van Leeuwen, C., et al. (2020). Diversity buffers winegrowing regions from climate change losses. Proc. Natl. Acad. Sci. U.S.A. 117, 2864–2869. doi: 10.1073/ pnas.1906731117.
