XII Congresso Brasileiro de Viticultura e Enologia- Anais 55 Climate change: observations, projections, and general implications for viticulture and wine production1

1 Climate Change, Viticulture, and Wine The grapevine is one of the oldest cultivated plants that, along with the process of making wine, have resulted in a rich geographical and cultural history of development (Johnson, 1985; Penning-Roswell, 1989; Unwin, 1991). Today’s viticultural regions for quality wine production are located in relatively narrow geographical and therefore climatic niches that put them at greater risk from both short-term climate variability and long-term climate change than other more broad acre crops. In general, the overall wine style that a region produces is a result of the baseline climate, while climate variability determines vintage quality differences. Climatic changes, which influence both variability and average conditions, therefore have the potential to bring about changes in wine styles. Our understanding of climate change and the potential impacts on viticulture and wine production has become increasingly important as changing levels of greenhouse gases and alterations in Earth surface characteristics bring about changes in the Earth’s radiation budget, atmospheric circulation, and hydrologic cycle (IPCC, 2001). Observed warming trends over the last hundred years have been found to be asymmetric with respect to seasonal and diurnal cycles with greatest warming occurring during the winter and spring and at night (Karl et al., 1993; Easterling et al., 2000). The observed trends in temperatures have been related to agricultural production viability by impacting winter hardening potential, frost occurrence, and growin