Wines in a Hotter World

Wine grapes are like the canary in the coal mine for climate change. Vitus vinifera, the common grape vine that produces the world's premium wines, have a fairly narrow band of climate area they do well in. Within these climate zones, particular regions will grow Cabernet while others grow Chardonnay and so on.

In Sonoma County, there are cooler regions for grapes such a Chardonnay and Pinot Noir. Cabernet, Zinfandel, and most other grapes would not ripen where Chard and Pinot do. Likewise, the best Cab regions are too hot to make quality Chardonnay and Pinot Noir.

So as the climate changes and temperatures rise, wine grapes will be some of the first to suffer.

Glass Fire, Sep-Oct 2020

In September 2022 we hit historic high temperatures. In the past five years, major fires have hit the Napa and Sonoma regions (and other parts of the state). The last official water year (Sept 2020 through Oct 2021) was the driest in over a century. I haven't seen the numbers for the water year that just ended, but it was better than the previous year, though still below the average. 

What do higher temperatures mean for wine grapes? Some vineyards will be in too hot of a location for the variety planted, so replanting to a warmer climate grape will be necessary.

Using Napa Valley as an example, the southern end is situated near the cool waters of the San Pablo Bay which connects to the San Francisco Bay. This region is known primarily for cooler climate grapes like Chardonnay and Pinot Noir. As you go upvalley summer daytime temps warm significantly and Cabernet Sauvignon does quite well. 

In the short term, as the climate warms, wines get fruitier and softer (less natural acids). In the longer term, if the temperatures rise enough, Napa's famous Cabernet might have to move south to more temperate regions of the valley or even other parts of the state or farther north on the West Coast. The hottest Napa upvalley areas may be switching to hotter weather grapes like Tempranillo and some you've never heard of, as there's experimentation going on now with obscure grapes and clones designed for a hotter world.

Will this Napa vineyard still be planted to
Cabernet Sauvignon in 50 years?