Historical and contemporary climate changes

The grapevine is one of the oldest cultivated plants and, along with the process of making wine, has resulted in a rich geographical and cultural history (see origins of viniculture). History has shown that wine-grape growing regions developed when the climate was most conducive. In addition, records of dates of harvest and yield for European viticulture have been kept for nearly a thousand years, revealing large swings in growing season temperatures and productivity. For example, Pfister’s historical research describes how during the medieval ‘Little Optimum’, roughly ad 900–1300, average temperatures were up to 1 °C/1.8 °F warmer with vineyards planted as far north as the coastal zones of the Baltic sea and southern England. Recorded harvest dates for northern Europe from the High Middle Ages (12th and 13th centuries) show that fruit was ripening in early September as compared with late September to mid October during the late 20th century, and that growing season temperatures were roughly 1.7 °C/3 ºF warmer. However, during the ‘Little Ice Age’ (14th to late 19th centuries), temperature declines were dramatic, resulting in northern vineyards being abandoned and growing seasons so short that harvesting ripe grapes even in southern Europe was difficult. Recent research by Chuine and colleagues used contemporary grape harvest dates from Burgundy to reconstruct spring-summer temperatures from 1370 to 2003. While the results indicate that temperatures as high as those reached in the warm 1990s have occurred several times in the region since 1370, the extremely warm summer of 2003 appears to have been hotter than any other year since 1370.