There are few economic aspects that have been documented in such detail over the centuries as the interaction between climate and wine quality. Apart from the soil, the climate of a production area is the most important part of the terroir – it is essential for the character and distinctiveness of a wine style.
However, we are currently at a point where our climate is changing and becoming more extreme from year to year. Heatwaves, storms such as unseasonable heavy rain, hail and any other freak weathers are no longer a rarity but part of our everyday life. Climate change is threatening viticulture and agriculture – however, while consumers generally do not care where their potatoes at a stable price come from, a Bordeaux remains a Bordeaux and its price can rise or fall twentyfold, depending on the vintage. The climate therefore not only influences crop yields, a wine's alcohol content and storage life but also the economic aspects of an entire wine growing region.
Extreme summers interfer with the vine's metabolism, as well as a wine's colour and aroma. The stored sugar in the grapes increases, in red wines usually by twice as much as in white wines, resulting in denser wines with higher alcohol content and lower acidity. The summer of the century in 2003, for example, is one of the worst Bordeaux vintages of the past 100 years. The abnormal temperatures put the vine under drought stress – before it dies outright of thirst. Winemakers are forced to harvest the vine before it reaches perfect physiological maturity, resulting in unbalanced wines with poor ageing potential and often with atypical ageing notes. A bit of assistance could be provided by artificial irrigation, as used in Southern Europe or California. However, this is associated with high costs and therefore hardly affordable for small houses.
In Europe, this measure is still considered to be too influential anyway. For areas close to the equator or generally hot countries like Greece, which already processes most of its grapes into raisins, the steady rise in temperature and drought will mean the end in the long term. But there are not only losers in terms of climate change and viticulture. England, for example, is one of the winners with its sparkling wines that will compete with nearby Champagne over the next centuries. It is simply getting too warm in Champagne for Pinot Noir, Pinot Meunier and Chardonnay and they are fleeing across the English Channel to the British Isles 350 kilometres away. The soils here are similar to those on the Côte de Blancs, chalk-based and deep, so the vines can root well – the climate is more bearable. So the trend is towards vines migrating north, something that is not alien to Europe. It is assumed that Europe has undergone several climatic changes during the last two millennia, and that viticulture's northern border extended as far as northern Germany during the medieval warm period.
Cool climate grapes, such as Müller-Thurgau and Blauer Portugieser, are moving to Saxony, the Palatinate is starting to grow grapes like Syrah, Chenin Blanc and Viognier, which are at home in more southern climates. For the German winegrowing industry, this poses a different problem, as we still have a lot of room at the top of the grape variety range. Things are getting more serious for countries that are already at the end of the hot climate grape varieties. Now, however, Europe is also faced with the problem that the EU requires a planting right for the new planting of vineyards, which was originally introduced to limit the European vineyard area and its yields and is now hindering viticulture from moving north. In addition, many European wine-growing regions have strict rules for the selection of vines. The interplay between the grape variety, climate and soil must be reconsidered and redefined here. European viticulture will definitely change, but historically it has already done so several times. So it's up to us to make the best of it.