WINE AND CLIMATIC CHANGE

Picture showing the extreme drought in our planet

Climate change is a scientifically proven reality that will significantly change wine production in the coming years. In its simplest sense, an average temperature increase of around 1.5 ºC is expected over the next 15 years compared to the temperature at the end of the 20th century, but this could reach up to 4.8 ºC in the most extreme scenarios of uncontrolled CO2 emissions. Under these conditions, it is estimated that up to 50% of the current vineyard area could be at risk of disappearing, mainly from the current warm production areas (Mediterranean basin, California), to the benefit of new production areas in higher latitude regions1. The wine industry has for some time now been assessing the challenges and opportunities that this transformation, unfortunately very difficult to reverse, will bring to the sector in the form of adaptation to the new climatic conditions and innovation in cultivation and production technology. Some of the risks associated with climate change identified by the production companies are related to greater production volatility (associated with droughts or extreme weather effects), changes in the harvesting process (less spaced and shorter harvests), greater risks of pests and diseases, or the need to modify current vine varieties for others with greater resistance6.

Vitis vinifera, in all its varieties, is particularly sensitive to growing temperature. Most varieties have a very narrow temperature range (barely 2-3 ºC)3 in which their qualities are optimally expressed, which means that their preferred growing areas extend around the 50 N and 45 S parallels: too hot and unbalanced and uninteresting wines are produced; too cold, and acidic wines with low alcohol content are produced. The phenology of the vineyard is conditioned by the temperature factor and the harvest date is expected to be more than 20 days earlier than at the end of the last century in some Mediterranean areas2. Although in the short term it will be possible to adjust harvesting times and growing conditions by means of appropriate agricultural techniques, in the medium term, the combination of both factors suggests that traditional varieties in certain areas will be displaced by new varieties better adapted to the new climatic conditions, radically affecting the expected characteristics of the wine produced, something that would particularly affect those territories with PDO regulations such as Spain, France or Italy. These varieties could be either chosen from among those best adapted to higher temperatures, or hybridized or genetically selected for their better resistance4.

Photograph of a vine with dry fruit

The increase in temperature has a direct correspondence with the composition of the wine, increasing the concentration of sugars in response to the heat stress suffered by the plant, which means a higher potential alcohol content. Under the effect of heat, berries accelerate their ripening and increase their metabolic processes, leading to a change in the ratio of sugars (increase, mainly due to berry dehydration) and acids (decrease, mainly due to thermal degradation of malic acid) that directly impact the characteristics of the must produced5. Potassium levels also increase, resulting in a higher pH of the must, even reaching values above 4.0. Phenolic compounds are also affected, although in this case not only the temperature is relevant but also the degree of exposure to sunlight; thus, for example, the synthesis of anthocyanins is inhibited at high temperatures, while the presence of astringent phenols increases. The result is a significant mismatch between technical and phenolic maturity.

Some of the effects of climate change would have a direct impact on the cultivation techniques used to counteract the effect of increased temperatures in the form of increased presence of irrigation in the vineyard (especially in areas where precipitation is expected to decrease), changes in cropping and pruning patterns to reduce sun exposure, applications of sunscreens to reduce the effect of UV radiation, or shifting cultivation to higher altitudes. The biggest problem for its implementation lies in the strict conditions required by the regulatory councils to grant the ‘protected designation’, which reduces the attractiveness for consumers who have traditionally identified these PDs as a guarantee of certain characteristics.

Having methods to control winemaking processes, to be able to verify and, if necessary, correct through the application of appropriate oenological techniques, is an essential tool to support winemakers in the production of wines that maintain the desired quality standards in a process of constant adaptation to the effects of climate change. Sinatech offers the most advanced analytical systems on the market that incorporate the most innovative technologies to provide optimal results.

REFERENCES

  1. Intergovernmental Panel on Climate Change (IPCC). (2013). Summary for policymakers. Stocker, T.F., Qin, D., Plattner, G.-K., Tignor, M., Allen, S.K., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P.M. (Eds.), Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge: Cambridge University Press, 3–29.
  2. Ferrise, R., Trombi, G., Moriondo, M., and Bindi, M. (2016). Climate change and grapevines: A simulation study for the Mediterranean basin. Journal of Wine Economics, 11(1), 88–104.
  3. Jones, G.V. (2006) Climate and Terroir: Impacts of Climate Variability and Change on Wine. In: Fine Wine and Terroir – The Geoscience Perspective. Macqueen, R.W., Meinert, L.D. (eds) Geoscience Canada Reprint Series Number 9; Geological Association of Canada; St. John’s, Newfoundland: 247 p.
  4. Duchene, E.; Butterlin, G.; Dumas, V.;Merdinoglu, D. Towards the adaptation of grapevine varieties to climate change: QTLs and candidate genes for developmental stages. Appl. Genet. 2012, 124, 623–635.
  5. Coombe, B.G. (1987). Influence of temperature on composition and quality of grapes. Acta Horticulturae, 206, 23–36.
  6. 2019 ProWein Business Report: Climatic Change (http://www.prowein.de)

For more than 10 years, Sinatech’s commitment to the winemaker has been working side by side to provide the most appropriate analytical solutions to the control and monitoring of the winemaking process. Automated methods easily adaptable to any work routine, with a personalized advisory team to help you quickly and smoothly implement.

Sinatech: TeamWork.