Climatic Wine Growing Potential under Future Climate Scenarios in Austria Josef Eitzinger 1 , Gerhard Kubu 1 , Herbert Formayer 1 and Thomas Gerersdorfer 1 1 Institute of Meteorology, University of Natural Resources and Applied Life Sciences (BOKU), Vienna, Peter-Jordan Strasse 82, A-1190 Vienna, Austria. Abstract. A significant warming trend is expected in Austria, as in many Central European regions during the next decades, leading to a large shift of agroclimatic zones. These shifts will change land use in agriculture over large regions in the long term. Wine is known as a crop which climatic demands are relatively well known for several climatic parameters. According to these climatic growing limitations, the borderline of wine growing climate will significantly shift due to climate warming in Austria due to the significant climatic gradients. In this study, based on the EU-project ADAGIO, the change of wine growing potential areas in Austria is analysed under several climate scenarios using agroclimatic indices such as the HUGLIN index. According to the results a doubling of potential wine growing areas is expected till the 2050s for several regions in Austria. Introduction Grapewine is known as a good climatic indicator because of his long life cycle. Wine harvesting dates, for example, are used in historical climatology to detect and describe historical climatic changes and variability as these data were recorded well over the past centuries in Europe because of the economic importance of wine. According to Harlfinger et al. (2002) wine growing in Austria is limited by several climatic limitations such as temperature sum during the vegetation period, sunshine hours, minimum temperatures in winter or annual precipitation. In Austria and over Europe the HUGLIN index (or Heliothermal index), which is based on temperature sums during summer can represent relatively well the current wine growing areas at the larger regional scale. However, for a small scale assessment, considering local climatic phenomena in complex terrain, additional limitations have to be applied, such as terrain characteristics or small scale variations in temperature extremes (Eitzinger et al., 2009). Data and methods Long term daily weather data from the period 1971-2000 were used as reference period to calculate the HUGLIN index (e.g. Tonietto and Carbonneau, 2004) for Austria. The Huglin index, a temperature sum based index for the growing period, is as follows: HUGLIN = ((Tmax – 10) + (Tmean – 10) * K) / 2 where T is daily temperature from April till September in °C and K is a coefficient for latitude (1.02-1.08 vs. 40°-50°). Climatic scenarios of daily weather data for the period of 2041-2050 (HadCM3, SRES A2) were applied for future climate to calculate the index over Austria in a resolution of 10x10km in order to assess the potential wine growing areas based on this index (Eitzinger et al., 2009). In order to create a higher spatial resolution of the temperature and precipitation field over Austria, a monthly climatic data base at 1x1km resolution was used for further analyses. Based on this high resolution temperature map, the HUGLIN index results and information on historical archieved wine growing regions in parts of Austria the limitations from annual temperature and precipitation were extracted. Finally the relative changes in temperatures of the climate scenarios were applied on that high resolution scale. A further limitation of potential wine growing locations was applied using GIS implemented algorithms to detect the preferred climatic locations for vineyards, namely slopes and the slope aspect from south to eastern directions, as it is also the observed prevailing terrain condition in current wine growing regions of Austria. Results and disscussion The results for the region of Upper Austria, where currently no significant wine growing areas exist are shown in the following. For this region the historical wine growing region of the warm period of the middle age was used to assess the annual temperature and precipitation limitation. The temperature limitation for the annual temperature was set at 9.5 °C as also pointed out be Harlfinger et al. (2002). The annual precipitation limit, which is closely correlated to annual sunshine hours, was set to 1100mm. In Fig. 1 the change of the HUGLIN index during the past decades at 3 different regions in Austria (represented by meteorological stations Vienna, Graz and Kremsmünster) is shown.