How Climate Change Could Redraw California Wine Country Maps

"Climate change will restructure viticultural suitability in spatially complex and region-specific ways," researchers from the Department of Civil and Environmental Engineering, Tohoku University, Sendai, Japan, warn in a just-published paper in Frontiers in Climate.

The study finds "substantial declines in climatic viticultural suitability across major regions such as Napa and Sonoma. along notable increases in northern and coastal areas under high-emission scenario in future climate." In other words, Napa and Sonoma become less desirable for vintners. Meanwhile, "areas such as Mendocino and Monterey exhibit increasing suitability coupled with decreasing extreme fire-weather days, identifying them as comparatively favorable expansion zones."

But what about wine quality? The study says fire-weather conditions differ by variety. "In Sonoma, Chardonnay tends to achieve higher quality in years without extreme fire weather but declines in high fire-danger years, whereas Pinot Noir shows the opposite tendency."

The study calls climate change "a fundamental challenge to the global wine sector," and notes wine production is exceptionally climate-sensitive because grape yield and quality are tightly constrained by environmental conditions, and because wine value is inseparable from place."

It notes climate change is altering not only mean climatic conditions but also the frequency and intensity of extreme events such as wildfires, which it describes "as a particularly consequential threat to wine-producing regions, especially those with Mediterranean-type climates."