Climate change may wipe out more than HALF of wine-growing regions
could wipe out more than half of the world's present wine-growing regions and force vineyards to change varieties in order to keep operating. Researchers led from Harvard University in the US found that just 2C of warming would cut the amount of suitable wine-growing regions by as much as 56 per cent. However, trading their current grape varieties up for more heat-tolerant varieties could help keep some vineyards in business. For example, 'warmer' varieties like mourvedre could be grown where cabernet sauvignon, merlot and pinot noir is currently cultivated. These cooler-temperature grapes could then by grown in new wine-producing regions north of their present locations. However, climate change will hit already hot regions like Italy and Spain the hardest, which will have no more-heat-resistant varieties to trade up to. 'Substituting grenache or cabernet sauvignon for pinot noir, planting trebbiano where riesling is grown these aren't painless shifts to make,' said food and conservation scientist Elizabeth Wolkovich of the University of British Columbia. 'But they can ease winegrowers' transition to a new and warmer world.' Professor Wolkovich and colleagues found that if average global temperatures rise by 2C, the regions of the world that are presently suitable for growing good wine grapes could shrink by as much as 56 per cent. With 4C warming, however, the loss of global wine-growing regions could increase to 85 per cent. 'These estimates, however, ignore important changes that growers can make,' Professor Wolkovich added. 'We found that by switching to different varieties, vintners can lessen the damage to just 24 per cent of areas lost.' In their study, the researchers focused on 11 varieties of grape: cabernet sauvignon, chasselas, chardonnay, grenache, merlot, (mourvedre also known as monastrell), pinot noir, riesling, sauvignon blanc, syrah and ugni blanc. Based on past studies and vintner archives, the team built a model to determine when each variety would bud, flower, and ripen in wine-growing regions around the world under three different scenarios that considered 0C, 2C, and 4C of warming. From this, they determined where each variety would be likely to produce viable harvests or not in each possible future. The team found that a reduction in wine-producing regions was unavoidable in both of the warming scenarios, thanks to shifting temperatures and seasonal changes that would affect conditions while the grapes were ripening. However, they also discovered that by switching around the locations in which different varieties are grown, it would be possible to 'reduce losses by a significant amount.' In fact, such adaptations could halve the potential losses of wine growing regions under the 2C warming scenario and cut such by around a third from 85 to 58 per cent in the 4C scenario. Other measures like increased irrigation and the use of shade cloths could also help to protect grapevines from higher temperatures, but only under smaller warming scenarios. In France's Burgundy region, for example, the researchers found that heat-loving mourvedre and grenache varieties could replace traditional grapes like pinot noir. Meanwhile, mourvedre could also be produced in the vineyards of Bordeaux that once cultivated cabernet sauvignon and merlot. The largest losses would be observed in those wine-growing regions that are already hot today such as those in Australia Italy, and Spain as vineyards there are already limited to the species of grape that grow in the warmest temperatures. In contrast, cooler wine-growing regions such as those found in Germany, New Zealand and US Pacific Northwest could remain relatively unscathed in the 2C warming scenario. These regions, the team suggest, would become suitable for growing warmer-temperature varieties like merlot and grenache while cooler-temperature varieties like pinot noir could be grown in more northern areas. The researchers acknowledged, however, that there will be both cultural and legal hurdles to surmount if grape varieties are to be shuffled around. 'The effectiveness of any strategy depends on both the grape growers and people in general,' said Professor Wolkovich. 'Consumers who are willing to try new varieties can play a big part in helping save the regions people love.' 'Legislation can encourage growers to test out new varieties. And ultimately, people can make the largest impact through work to reduce emissions globally.' The full findings of the study were published in the journal .