he changing climate is a major threat to Napa Valley’s wine industry. Atmospheric rivers can flood vineyards, damage budding vines, and erode soils. Fewer winter frosts can encourage the spread of pests. Extreme heat can shrivel crops and push the acids in the fruit out of balance. Wildfire smoke can taint the grapes and leave them unsaleable. These factors not only drive up the price of production, but ultimately could affect the viability of grape production itself.