California premium wines a victim of climate change

The cost of averting climate change is often argued as a reason to do nothing. But climate change also has severe economic consequences. Among them: a nice, cool glass of premium California chardonnay.

A new Stanford University study reports that by 2040 the amount of land suitable for growing high value wines in Northern California could shrink by half as a result of higher temperatures. That would take a severe blow to the country’s wine industry. California produces 90 percent of the nation’s wine production, valued at $18.5 billion in 2010.

Photo: Philip Bouchard

The study, published in the June 30 edition of the journal Environmental Research Letters, was based on an average global temperature increase of 1.8 degrees Fahrenheit, which is considered a relatively conservative estimate and the limit needed to avert catastrophic impacts. That temperature increase is actually on the low side of what’s expected in Napa Valley, which is projected to go up about 2 degrees with the number of very hot days increasing by 10.

The amount seems small but the impacts are devastating for premium grape varieties, which are extremely temperature sensitive. If growers switch to lower quality varietals that are more heat tolerant, then the acreage for wine growing could increase.

Knowing all this, what will Northern California growers choose to do?

“Climate change over the next few decades is of particular relevance for the wine industry,” said Noah Diffenbaugh, an assistant professor of environmental Earth system science at Stanford in a press release. “It’s a big investment to put plants in the ground. They’re slow to mature, and once they mature they’re productive for a long time.”

For growers, planning for the future requires a leap of faith. Climate science is not an exact science, but doing nothing could be worse.