# A Review of the Potential Climate Change Impacts and Adaptation Options for European Viticulture
## 4 Potential Climate Change Impacts
### Climate Change Projections and Impacts on Grapevines
UV-B radiation has an impact on grape composition, with modifications in secondary metabolites, such as flavonoids, amino acids, and carotenoids [134]. Irrespective of a further future increase in UV-B radiation, the combination of high radiation levels and high temperatures, particularly under severe water stress, is often responsible for sunburn damages in both leaves and berries [139; 140], conditions that are anticipated to become more frequent in Southern Europe. Crop protection may be another critical aspect of changing climates. It faces mostly two challenges: (i) pests and diseases from warmer regions may increasingly survive during warmer winters and (ii) the spectrum of existing pests and diseases may change. An example of a new challenge posed by an invasive species in viticulture is the spotted wing drosophila, a fruit fly that is native to Southeast Asia, but has been spreading to the USA and Europe since 2008. Whereas the spreading is a result of increasing globalization and not climate change, the survival and continuous spread into new areas of this species is due to increasingly mild winters [141]. Data from three decades on selected grape pests point to changes in the phenology of grape berry moths, shifts in distribution ranges of leafhoppers as vectors of grapevine diseases, and range expansion of grapevine mealbybugs [142]. On the one hand, temperature increases resulting from climate change are likely to allow for more pest generations per growing season, however, at the same time, fruit maturity and thus harvest dates are expected earlier, limiting damage from late-season pest generations [143]. Climate change may also result in decreasing disease pressure and, consequently, a reduced necessity for the use of pesticides, as was demonstrated for powdery and downy mildew in the region of Burgundy [144]. However, at the global level, mildew are likely to remain the major phytosanitary threat [145]. Modifications in interannual variability and extremes of the meteorological conditions are showing a profound influence in the year-to-year variations in yields and wine quality [56; 94]. Extreme weather events, such as heatwaves, extreme precipitation, droughs, hailistorms, and windstorms, among others, are more likely to occur in the future [146] and, as a result, may also have an important impact on future viticulture. Overall, climate change is expected to significantly change grapevine growth, development and yield, grape berry attributes, wine style and typicity, and, hence, the perception of the terror of many traditional viticultural regions [2; 80; 147], thus requiring adaptation to warrant future sustainable viticulture. Despite the genetic diversity amongst grapevine varieties and clones within varieties, as well as the resulting plasticity in their adaptation to a wide range of climates [148], there are suitability limits that cannot be exceeded to maintain viticulture both environmentally and socioeconomically sustainable in a given region.