Treacherous frost, heat waves, precipitation. Climate change and its destructive consequences have also long since arrived in viticulture. The industry, which often only features top winemakers, is under pressure to adapt – to invest in the future. Because when temperatures rise, grapes ripen faster, their alcohol content increases, color and aroma suffer, and the character can change. Winegrowers around the world are not staying idle. German winegrowers are also arming themselves – for example by growing more heat-loving grape varieties that were long limited to southern regions. Will Rheinhessen soon become the new Roussillon-Langedoc?
The Intergovernmental Panel on Climate Change predicted years ago that climate change would change the geographical distribution of wine varieties due to warmer environments, erratic precipitation patterns and soil erosion: Wine products and the livelihoods of entire regions could suffer losses in value. As of today, German viticulture “is by and large still one of the winners,” reassured the German Wine Institute. What scientists predicted to the Bundestag in 2016 happened: At the northern end of world winegrowing, winegrowers will “benefit from the increased average temperatures of recent years”.
Plus one degree Celsius in 30 years – this means that German wines achieve higher degrees of maturity and better quality, especially the red ones. “But the increasing number of extreme weather events also entail more and more risks for German viticulture,” warns the DWI. Hail damage is increasing, sunburn on grapes dries up berries, which in turn can cause bitter tones in red wine production. Considered a “cool climate” grape variety, Riesling does not like growth-retarding, dry summers. The rain often comes at the wrong time for him, or too much at once.
Nevertheless, the Riesling with 24,000 hectares of vines will not be pushed out of its top position among the local vineyards anytime soon. At the same time, winegrowers are adapting in new directions, preparing strategic decisions: vines have a long lifespan, a new vineyard takes five to six years to bring full yields, and it can take 20 years to make a profit. More and more winegrowers are boldly opting for grape varieties that are either more robust or actually feel at home 200 kilometers further south.
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This is shown by the latest figures from the Federal Statistical Office. According to this, the area under vines for Sauvignon Blanc grapes in Germany more than doubled between 2012 and 2022 by almost 162 percent to a good 1900 hectares. In addition, white Burgundy varieties have recently been in vogue, the areas of which grow faster than those of Riesling. Of internationally important varieties, the easy-care Chardonnay increased by 83 percent to a good 2700 hectares, the southern red wine varieties Merlot by 59 percent to 886 hectares and Cabernet Sauvignon by 43 percent to 483 hectares. According to the Wine Institute, the latter make up less than two percent of all German viticulture. But winegrowers are daring to do something new in the area, even experimenting with varieties such as Shiraz/Syrah, Cabernet Franc or the Spanish Tempranillo.
You have to plan for the future – a vineyard stands on average around 25 years. At the same time, among the fruits, grapes react most sensitively to climatic changes. The problem of late frosts, which can disrupt entire layers during budding, contributed to major losses in France in 2022. The earlier the vines blossom, the higher the risk of damage, because the frosts hardly change in time. Rapidly rising temperatures accelerate premature ripening phases. Too much heat combined with increased radiation intensity causes sunburn. Vines under drought stress can be irrigated in a targeted manner – but this is not a sustainable solution for a luxury product.
Especially in zones like Italy, the leading wine country with 19.3 percent of global production. With France and Spain, the three countries fill half of the global wine lake. All three are experiencing increasingly warm winters and water shortages. The traditional varieties that characterize the southern Mediterranean are quite heat tolerant. Wine connoisseurs expect that their cultivation will tend to migrate north because of the rise in temperature and a different distribution of precipitation.
Italy’s leading Sangiovese – like Montepulciano today distributed throughout central Italy – is considered sensitive to environmental conditions and not very adaptable. Similar to the Nebbiolo in Piedmont. Instead of a difficult change of variety, winegrowers are experimenting with rootstocks that, thanks to their root system, are better able to withstand drought stress. The proximity to the sea and lakes does reduce the effects of global warming on viticulture. But extreme air and water temperatures and a lack of rain cause problems.
While the Cabernet and Chianti varieties mature better, Pinots migrate to higher altitudes. In the far south, however, replanting as a counter-strategy is largely absent, since the most heat-resistant wine varieties are already being cultivated. In Sicily, for example, the Merlot grape suffers from a lack of moisture, and winegrowers are required to improve foliage and soil.
In the worst case, entire regions could be threatened with the loss of varietal identity, warns the climate expert among Germany’s wine professors, Hans Reiner Schultz, from the leading wine university Geisenheim, in a co-authored study. Driving forces of climate change can shift the regional suitability of a wine region, day and night, summer and winter temperatures, water balance, all of which influence budding, flowering and ripening phases. “Winegrowers today have to react to what awaits them in 25 and 50 years,” he warns in an interview.
A warning call, which the French National Wine Institute (INRAE) also joins in: What is happening today in the Languedoc-Roussillon wine region, which is plagued by drought, is like a laboratory and “could be the reality in the Rhone Valley in ten years’ time”. In this way, the top regions in particular do not remain idle. However, since Bordeaux wines are difficult to produce further north, winegrowers are turning to the late-ripening Petit Verdot variety. After ten years of research with climate scenarios, the winegrowing council had six additional grape varieties officially approved for adaptation.
The red grapes Touriga, Arinarnoa, Castets and Marselan as well as the white Alvarinho and Liliorila are considered to be heat resistant and may now be cultivated sparingly at first. The rules of origin are strict. If winegrowers plant fruit trees in Burgundy in order to gain shade and moisture for the vines, each one must be applied for. The area of origin is also protected as a cultural heritage.
There is also a lot at stake for Spain, the world champion wine exporter, and its multi-billion dollar industry. The summer of 2022 was the hottest on record. Winemakers in the Mediterranean like Catalonia are looking for cooler heights at the foot of the Pyrenees. In the Rioja region, which produces a fifth of the wines, up to 10 percent less was pressed in four difficult years due to high rejects. Research institutes are reviving a dozen grape varieties up to 100 years old that, thanks to their genetic diversity, are better able to cope with droughts.
The need for more resilient varieties is increasing even in central continental Spain, where Castile-La Manche produces not only Manchego cheese but almost half of the wine – 40 percent irrigated. As is the case everywhere, soils should be cultivated in such a way that they hold more water, the leaves should be shaped in such a way that they provide more shade, and rows of vines should be arranged in a more climate-friendly manner. Experts are arguing about the southernmost Mediterranean and dry zones such as Analusia or Murcia as to whether viticulture can be saved by changes in cultivation technology.
According to studies, about 60 percent of the world’s wine-growing regions are in semi-arid regions such as the Mediterranean, where global warming is threatening the economic sustainability of historical dry agriculture. The proportion of irrigated vineyards is steadily increasing. But even in Australian viticulture there is now an urgent discussion about switching to more heat-tolerant varieties that do not require irrigation – including Italian classics such as Nero D’avola, Sangiovese or the high-quality Nebbiolo, Barbera and Dolcetto. In South Australia, winemakers with varieties that traditionally love temperate zones – Riesling, Chardonnay or Pinot Noir – are moving to higher altitudes. Others are experimenting with emerging strains that are more resilient through delayed ripening or thicker skins.
Drip irrigation to maintain yields on threatened sites has recently also increased in Germany. This year, however, it was possible to act sparingly. The water supply was sufficient in most wine regions and the harvest is expected to be significantly better than the average for the previous five years, according to federal statisticians these days. With a stable area under cultivation, almost 9.9 million hectoliters of wine and must are expected – an increase of nine percent and about a fifth of the amount in Italy. In the course of global warming, wine is now at home in all federal states: in 2020 it also arrived in Lower Saxony. Farms that focus on high quality need more terroir for the vine. Some grow north.
If you listen to Professor Schulz from Geisenheim, he is still concerned about the pace of adaptation to climate change in German winegrowing. Climate simulation scenarios for an average vintage of 2050 had already become reality in 2018. A spokesman for the Wine Institute is confident: “We see the German wine industry as well prepared for the challenges posed by climate change.” Structural change cannot be expected overnight. Modified and ripeness-delaying cultural measures, new clones of grape varieties or new robust varieties could also ensure the cultivation of traditional vines. Supplemented by an increasing number of fungus-resistant grape varieties, around three percent of the cultivated vineyards were “planted with robust varieties” in 2022.
Surely this can only be the beginning. But it is particularly difficult for smaller producers to manage the changeover financially. In any case, their number is steadily decreasing. They are being taken over by larger wineries of more than ten hectares, which are growing both in area and in number. “In order to be successful in the market today and to work economically efficiently, you need a certain size,” says the DWI. On average, only about 2-3 percent of the vineyards in Germany would continue to be newly planted. Because that costs 40-50,000 euros per hectare today. Instead, many winegrowers experimented with site refinement, which allows the variety to be changed in one year without clearing – another possibility thanks to increased temperatures.
In the meantime, they are also giving new impetus to winegrowing in Northern Europe. In this way, Swedish viticulture is changing from being largely run by small amateurs to an industry with lofty goals. The conditions have become more stable: According to the Swedish Institute for Meteorology and Hydrology, temperatures in southern Sweden have risen by around two degrees Celsius in the past 30 years compared to the 30 years before. The growing season lengthened by about 20 days.
Most Swedish wineries cultivate the Solaris grape variety, which was developed in Germany and likes a cooler climate. While the area under vines there is still tiny at under 200 hectares, experts predict that the UK will double in the next ten years. Some regions in northern France’s Champagne region suffer from excessive humidity, while global warming has turned southern England into a fertile wine-growing region. The winemakers there – including offshoots from Champagne – are now serving the growing demand for British sparkling wines.
