Benefits of climate change
Global warming may also result in a shift in the distribution of grape cultivation, meaning that wine production might become profitable in regions formerly unsuitable or marginal for wine-growing (7). Most wine-producing regions in Western and Central Europe have benefitted from increasing temperatures, but the impact of global warming obviously varies according to the type of wine produced and the geographical location (8). Areas that may be suitable for viniculture will increase especially in northern Germany, Denmark and southern England (2). In fact, the area that is being used for viniculture in southern England has already increased by 250% between 1985 and 2000 (3). It is to be expected that higher temperatures and CO2-concentrations will benefit viniculture in Germany (1,4). In southern Germany more and more wines are already being produced that used to be produced further to the south only (1).
Amongst others the vegetative period lengthens when temperatures, especially spring temperatures are increasing. Clear changes in the dates of phenological vine stages are observable in Europe (5). In Alsace, budburst and flowering events occurred about two weeks earlier in 2003 compared to 1965. The period between flowering and change of colour of the berries (véraison) shrunk by 8 days and the véraison date occurred almost 23 days earlier (6). In Murg (Switzerland), the flowering event advanced to earlier dates by 22.1 days in 47 years (7).
Previous studies predict a large potential increase in value of the vineyards at the Moselle river (8). Analyses of climate and phenological observations of white vine cultivars in the Upper Moselle region (Luxembourg and Germany) over the period 1951–2005 showed that vine phenology events, such as budburst and flowering, receed by about 2 days/decade. Budburst date and flowering events now occur earlier by about two weeks with respect to 1951 (4).
Due to changed climatic conditions during 1971–2010 the transboundary area of western Poland, eastern Germany and the northern part of the Czech Republic is now suitable for the cultivation of wine grapes, even for varieties that are demanding in terms of accumulated heat (10).
One of Germany’s historical wine-producing regions is that of Lower Franconia in the federal state of Bavaria. The vineyards are located along the Main River, which has the effect of moderating temperature, while the steep hills receive maximum heat and light exposure which enhances ripening (Jackson 2000). The cool conditions require the use of adapted grapevines (Vitis vinifera L.), which include frost resistant, late budding and early maturing cultivars. Grape cultivars most commonly planted are Müller-Thurgau, Riesling and Silvaner (5).
From a long-term (1949 to 2010) data set of vineyard observations in Lower Franconia, trends were shown of earlier phenological events, a shortening of phase intervals and increases in sugar content over the recording periods (5). These trends conform, in general, to results of other long term studies (6,9).
The observed warmer seasons during 1949 to 2010 have resulted in greater ripening potential for Müller-Thurgau, Riesling and Silvaner grapes. As a consequence, the sugar content increased while the acid component remains constant, resulting in a changed grape composition that has the potential to alter wine typicity and quality. Given that climate is projected to change even further in the future, these impacts are expected to continue and to become stronger. Thus, in the long term, the balanced ratio of sugar and acid content will shift in favour of the sugar component and may result in a loss of the traditional character of white wine produced in Franconia (5).
Under global warming, temperature will not be such a limiting factor for wine-growing in Franconia and therefore vineyards could expand to other, formerly unsuitable, sites. Increasing dryness in summer, intensified by higher temperatures and greater evaporation might lead to water supply becoming an occasional limiting factor. Warmer climatic conditions also favour the spread of grapevine pests and pathogens (5).
The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Germany.
- Stock et al. (2004)
- Harrison and Butterfield (1999); IPCC (2001), both in: Stock et al. (2004)
- Palutikof (2000), in: Stock et al. (2004)
- Neumann and Matzarakis (2011)
- Bock et al. (2011)
- Jones and Davis (2000); Duchêne and Schneider (2005); Webb et al. (2007), (2011); de Orduna (2010), all in: Bock et al. (2011)
- Lisek (2008), in: Bock et al. (2011)
- Webb et al. (2007); Duchêne et al. (2010); Hall and Jones (2010), all in: Bock et al. (2011)
- Neethling et al. (2012)
- Kryza et al. (2015)