The 2004 movie Sideways, starring Paul Giamatti and Thomas Haden Church, is in many ways a celebration of Californian wine, as main protagonists Miles and Jack meander their way across the state’s vineyards. In years to come, however, they may need to reconfigure their trip.
Climate change, along with the threat of wildfires, could fundamentally reshape California’s wine industry over the coming decades, according to new research published in Frontiers in Climate.
California produces approximately 80% of wine production in the United States – the US is the fourth-largest wine producer in the world – with Napa Valley and Sonoma County renowned internationally for their quality output.
According to the research, however, these regions, along with San Luis Obispo and Santa Barbara, are projected to face declining suitability for wine production under severe climate change scenarios.
At the same time, however, regions such as Mendocino, Monterey and parts of the central and southern California coast could become ‘new wine-growing powerhouses’ as the climate changes.
‘Comparatively favourable’
“Our findings reveal that the outlook for Mendocino and Monterey is uniquely promising because of a dual trend – they are projected to experience both increasing climatic suitability for wine-growing and a decrease in extreme fire-weather days,” commented Dr Yusuke Hiraga, an assistant professor at Tohoku University in Sendai, Japan, and corresponding author of the study.
“This combination makes these areas stand out as comparatively favourable expansion zones, distinct from many other regions with either rising suitability alongside increased wildfire weather or declining suitability.”
About the research
In undertaking the research, Hiraga, alongside Takuya Matsumoto, a master student at Tohoku University, examined 379 wine-growing locations in California, mapping projections from global climate models onto a four-square-kilometre grid, with each cell’s suitability for growing grapes and the expected quality of its vintage predicted with a machine learning algorithm.
The researchers then analysed two greenhouse gas emissions scenarios, representing both moderate mitigation and higher emissions, and examined climate conditions for the mid and late 21st century. Wine quality predictions were based on historical ratings published by Wine Spectator between 1996 and 2023.
As they found, the suitability of currently important wine-growing regions, like Napa, Sonoma, San Luis Obispo, and Santa Barbara, is ‘likely to decline strongly under severe climate change’, while other regions could potentially ‘increase greatly’.
“While our study highlights long-term shifts in climatic and fire-weather suitability through the end of the century, it does not attempt to predict a specific timeline for when emerging areas will surpass currently established regions in wine-growing potential,” Hiraga added. “Such a precise forecast is complex, as the future of viticulture is shaped not only by climate change and wildfire weather but also by a wide array of anthropogenic factors.” Read more here.
