Effects of Elevated Atmospheric Carbon Dioxide on the Vineyard System of Vitis vinifera: A Review

Global atmospheric carbon dioxide concentrations will continue increasing throughout the next century, with profound effects on agriculture. The literature concerning the effects of climate change on viticulture has largely focused on the isolated effects of variables such as temperature and soil water deficit. Likewise, the research on the effects of elevated atmospheric CO2 on grapevines is stunted at the categorical level, chiefly because of the difficulty of experimentally controlling the gaseous environment in situ for the years necessary to replicate the vineyard system in a future climate condition. Despite numerous studies on the short-term influence of environmental and cultural factors on grapevine development at elevated CO2, the long-term effects remain poorly understood. The lack of field based elevated CO2 experiments in the United States is an added challenge to predicting viticultural changes, particularly in California. This review focuses on the systemic effect of atmospheric CO2 on Vitis vinifera, synthesizing physiological, phenological, and plant-pest interactions. Major findings from this synthesis inform of a predicted increase in pest pressure, advanced phenological timing, transient increase in water use efficiency for grapevine, and changes in grape berry chemistry. While water use efficiency is highly desirable, the prediction for current winegrape growing regions is a transient increase in water use efficiency subsequently limited by a lack of available soil water. Grapevine is influenced by the negative synergistic effects of heat, drought, and elevated CO2, which will alter cultural practices including harvest and pest and disease control, with downstream effects on winemaking. Several options for adaptation are discussed including leaf removal, planting alternative varieties, and selective breeding of new varieties.