Climate change is not just a buzzword: it is affecting real vineyards, real people and the real economy. Its impact is so huge that the style of the wines are affected by it, the way viticulturalists work in the vineyard and cellar masters do it in the wineries is also changing. It will also need an adaptation of the appellation rules in the Old World in order for the producers to be able to compete on the global and very fierce global wine market.
Climate change includes the long term, regional to global changes that the climate registers (warming, cooling, changes in moisture regimes- precipitation patterns). These changes are brought about by greenhouse gases (CO2, water vapour – in far greater proportion than CO2, methane, nitrous oxide, HFC / CFC chemicals) gradually increasing the concentration of greenhouse gases. concentration. This increase will have to be moderated (loss of vineyards, disrupted growing cycle of the vine and of the life of the soils, rise in alcohol levels, higher disease pressure,…) and also exploited by viticulturalists (better quality grapes in cool regions, possibility to open new ones, less pressure of certain diseases, …). To these changes and their impact, viticulturists will react differently.
CO2 concentration has risen from 315 ppm (parts per million) in 1958 to 380 ppm today (Intergovernmental Panel for Climate Change – IPCC report). This situation has undesired impacts that have to be moderated.
Higher levels of greenhouse gases will render hot regions even hotter, making that viticulture will not be possible in areas like Aquitaine, Rhône Valley (France), Castilla (Spain), Italy except Sicily, Portugal except Algarve (Lee Hannah. Climate change, wine and conservation, 2013). New areas will have to be found. In dry viticultural regions, appropriate water management will become an ever pressing economic issue. Aurelio Montes, in Chile has tested dry farming on a large scale. He has reduced the use of water by 65% and seen that the size of the cluster ad berries decrease, getting more concentration and equilibrium, in the wines. The side effects is that there is less need to drop crop artificially to concentrate grapes. Berry weight goes from 1,1 g to 0,7 g and skin/pulp ratio goes from 12% to 37%. Aurelio Montes: “We want to go faster than climate”. The trade off is a drop in production of around 50%. This is the price to pay to be sustainable.
Cavit, in Trentino, the region’s largest cooperative, has developed a data-driven regional mapping system (Called PICA) that monitors water levels and adjusts irrigation based on the unique needs of each soil and vine type all over the Northern Italy Valley; the system reduces water usage and increases overall consistency of the grapes. Other efforts to combat decreasing levels of rainfall in some places involve the planting of drought resistant grapes like tempranillo, grenache and mataró in Australia and/or clones. The growing cycle of the vine will also be disrupted. From 36ºC, the roots stop any activity, disrupting the growing cycle of the vine. Moreover, the combined effect of increased temperatures and disrupted rainfall cycles will change the life of microorganisms like fungi, bacteria and acarids. Changes in the microscopic life will have an impact on the macroscopic life. A change of the microflora and microfauna (or a change in their distribution) will have consequences on the biogeochemical cycles (Claude Bourguignon). Life of soils will be affected as well. Increased winter rainfall in winter in the Northern hemisphere will increase erosion, resulting in impoverished soils. In Burgundy, the Monthélie, Corton and Vosne-Romanée appellations lose from 1 to 26 tons of earth per year (Jean-Pierre Garcia study. University of Burgundy). Certain vine diseases are spreading. In regions where temperatures have risen considerably (Beaujolais, Burgundy, California), mealy bugs, carrying the fanleaf virus, are progressing. In France, Flavescence dorée (phytoplasma associated with Leafhopper vector Scaphoideus titanus) has rapidaly spread from SW France to the rest of the country and further north to Germany (Rheinhessen). Under the combined effect of increased temperatures and increased moisture in the air (+7% with each degree Cº), fungi will most likely proliferate. Esca is the most worrying.
One other consequence of climate change is the rising the alcohol levels of the wines. In Australia, red wines have registered an increase from 12,3% to 13,9% between 1984 and 2004 while in Napa, between 1971 and 2001, they have risen from 12,5% to 14,8% (Gregory V. Jones, Past and Future Impacts of Climate Change on Wine Quality, 2006). Grenache has gained 2 to 3 alcohol degrees from 1983 to 2001 n Southern Rhône in France (InterRhône). In order to combat this negative aspect, Will Drayton, a viticulturist at Treasury Wine Estates has adapted his vineyards to extreme temperatures (up to 114 degrees), which shriveled many grapes in Napa Valley last summer. Of one specific plot, he declared it unfit for wine. It produced one ton of grapes per acre instead of the 3.5 tons it normally makes. In the desolate block where Drayton found shriveled grapes the orientation of the vine rows was changed to northeast by southwest so that the sun doesn’t pound on the grapes at its summertime zenith. To further shade the fruit, growers inserted “cross arms,” wires that encourage branches to bend over the grapes they produce, protecting them like an umbrella from the sun.
However, even if climate change has first unwanted impacts, it also has consequences that can be exploited by viticulturalists.
Cool regions can assure steady quality harvests and introduce new varietals. Regions like Alsace, Champagne, Bordeaux, Bourgogne, Loire Valley, Mosel and Rheigau can benefit from a warmer climate. But not only traditional regions are producing better wines. New areas for grape growing will be possible because frost occurrence will be lower, the growing season longer and winter hardening potential increased. It is the case of South Downs National Park in Sussex where Rathfinnyestate has been founded in 2010. It will have 160 ha by 2020. Ambitions are great: produce over 1 Million bottles of the world’s top class sparkling wines. The decision has been taken by owner Mark Driver to plant there because average temperatures in the area have been climbing since the 1980s to, in 2011, almost a degree higher than they were for most of the 20th century. Taittinger has recently also bought 75 ha of land in Sussex. Australian winemaker Nick Glaetzer has moved his shiraz operation to the southern state of Tasmania — a region that is about 38 percent cooler than in the traditional grape-growing region Barossa Valley in southern Australia because increased heat and dryness in the Barossa are impacting the quality of grapes, making it difficult to produce wine. The result is that the Tasmanian shiraz industry is growing at a rate of close to 10 percent per year, while Australia’s wine industry has steadily shrunk 1.9 percent annually for the last five years. And the shiraz produced in Tasmanian is less alcoholic, Glaetzer said — about 15-20 percent lower in alcohol content than the shiraz produced in the Barossa. Due to water restrictions and the increased risk of drought, in Mendoza, Argentina, winemakers will have to either plant higher or in more southern locations. Donald Hess, has planted his highest vineyard at 3.111 meters. A vineyard called La Joya, mostly planted with Pinot Noir was set up. The idea is to get fresher wines, explains Pierre Olivier Dion-Labrie, the manager of the project. In Italy, Aloïs Lageder has planted vineyards in the foothills of the Dolomites. Besides, he enhances the expression of the sense of place with biodynamic viticulture. In 2013, the Jackson family with operations traditionally based in Napa, has bought 200 ha of vineyards in Willamette Valley, Oregon. Other positive consequences of climate change are felt at vineyard level. Between 1994 and 2012, the weight of the grapes of Pinot Noir and Chardonnay have increased by 50% due to higher CO2 levels. (Source: CIVB), naturally increasing yields and preserving a balance in the wines. New varieties will appear. In South West France, the Plaimont cooperative has planted in 2002, 39 different grape varieties, some of them prephylloxeric ones. One of them, over 200 years old, is called Pédebernade 5 producing a wine with less than 10º abv. Some diseases, bacterial ones among others, will have less impact. Downy Mildew (DM) also known as Plasmopara viticola, is one of them, spreading when conditions are humid and temperatures between 55 ºF and 75 ºF might disappear in certain regions. For instance, summer 2003 was extremely harmful for DM in the Old World. Other consequences are registered in the cellar. In the Beaujolais, winemakers do not need to add sugar to the must to achieve the desired alcohol levels.
The plot 52 initiative.
Located in the heart of the Graves appellation in Bordeaux, this experimental vineyard was launched by the Institut des sciences de la vigne et du vin (Science Institute for vines and wine). It gathers 2.600 vines of 52 different French grape varieties (pinot noir, syrah, roussanne, marsanne, mourvèdre, carignan), Spanish ones (tempranillo, albariño), Portuguese ones (vinhao, touriga nacional), Greek ones (agiorgitiko, xinomavro), Bulgarian ones, Italian ones (sangiovese), known for the late growing cycle and their adaptability to drought and temperature stress. Called “Vitadapt”, from Vitis Adaptation, this ambitious program has the aim to identify the future grape varieties adapted to the future climate of Bordeaux. All investigators and scientists involved will make up a database of potential grape varieties that will translate the main characteristics of the region.
Last but not least, the evident impact of climate change on the future of winemaking worldwide has mobilized the industry. Sector initiatives, like that of Wineries for Climate Change, are launched. In the mid-200s, the Federación Española del Vino, in collaboration with FIVIN/VIMAC (Foundation to Protect Vines, the Environment and Consumers) has gathered wineries from several countries to discuss the impact of climate change and find solutions. Some wineries are very active participants. For instance, Fetzer Vineyards has participated in the Caring for Climate, the official Business Forum at the 2015 Paris Climate Conference ("COP21") sharing key successes and ideas for working towards a carbon-neutral future.
As a conclusion climate change poses threats and creates opportunities for the industry. Loss of vineyards, disrupted life of vines and soils, rise in alcohol levels, higher disease pressure will have to be combated (row orientation, dry farming, canopy management, clone selection, variety adaptation to soil and climate are some ways). On the bright side, some regions are consistently producing better wines, new areas will be suited to viticulture and some diseases will tend to disappear in certain areas. Last but not least, the industry is gathering efforts and working together to find new ways to handle the effects of climate change, which opens new perspectives and gives hope to all those affected.