Climate Change and the Future of winegrowing in Sonoma and Napa

Tue, Jan 13th 2009, 9:30am - 10:30am
"Global change in local places: Climate change and the future of high-quality winegrowing in Sonoma and Napa, California"

Presentation of research by Kimberly Nicholas Cahill, hosted by the Napa Sustainable Winegrowing Group (NSWG; http://www.nswg.org/)

For information contact Kimberly Nicholas kncahill@stanford.edu

RSVP requested.

--- Research Abstract ---

Agricultural systems are vulnerable to the impacts of changes in climate, with far reaching implications for how and where crops are grown for food, fiber, and energy. The ultimate extent of climate change, and thus society's ability to cope with climate change, depends importantly on the rate and degree of continued greenhouse gas emissions. However, adaptations to climate change are increasingly recognized as a necessary complement to reducing atmospheric concentrations of greenhouse gases. Using California's wine industry as a model agricultural system, I take an interdisciplinary approach to examine the climate sensitivity and adaptive capacity of both the ecological and social systems of winegrowing.

In a three-year study, I used field, laboratory, modeling, and anthropological approaches to examine the vulnerability of the wine industry to climate change. I examined the concentrations of anthocyanins and tannins in Pinot noir grapes from across a range of mesoclimates. I found that increased concentrations of these phenolic compounds were correlated with cool temperatures in the fall the year before harvest, warm temperatures from budburst to bloom, and cool temperatures from bloom to veraison, and with lower light intensities in these highly sun-exposed vines. Although wine quality is widely viewed as vulnerable to climate change, previously it has been poorly defined. Using grower responses from semi-structured interviews, I developed a typology of wine quality spanning a range of scientific and artistic values. These interviews also revealed that growers believe wine quality is most influenced by site factors such as climate, demonstrating the sensitivity of wine quality to climate change.

Growers undertake a wide variety of vineyard management strategies in response to environmental stresses. Most of these responses are individual in nature, and either in response to an existing stress, or in anticipation of an imminent stress. I examine the potential adaptive capacity of the wine industry to climate change, based on its awareness of climate change, ability to react, and actual actions and barriers to action. I conclude that winegrowers have a fairly high adaptive capacity, but that successful adaptation in practice depends on proactive and coordinated community responses, which are beginning to develop.