Reliability of climate change impact assessments for viticulture

Current assessments of climate change effects on viticulture are primarily based on global climate models. With respect to temperature and temperature-based indices, this may produce reasonable first approximations. Recent studies indicate that several viticultural regions may become more successful, and others less so, as high-quality wine production areas. However, it is not only average temperature but also a variety of other climate parameters and their variability that the allocation of chances and risks in impact assessments depends on. In this respect, global model resolutions are of limited value. However, current methods of regionalization by statistical downscaling or embedded regional climate models also show deficiencies and uncertainties. This paper presents a new method for the evaluation of regional climate scenarios using the statistical regional model STAR. This model offers improved applicability and reliability concerning viticultural aspects and primarily aims at evaluating measures of adaptation rather than predictions. The results demonstrate the extent and effects of climate change on viticultural areas in Europe. Possible impact on grapevine phenology and wine quality for the Rheingau and pest risks for Sardinia is given as example.