Could climate change warm your chardonnay? | Harvest Public Media

This story is part of a series of reports on climate change. Many California farmers are grappling with climate change and environmental regulations.

For a wine grape, where it's grown is one of the most important factors in determining its taste – and its value. 

"Where exactly the wine grapes are grown affects the price by a matter of two orders of magnitude," said Dan Sumner, an agriculture economist at University of California Davis.

In the middle of the Central Valley, wine grapes could go for around $200 a ton, he said, but in Napa, they could bring in $4,000 a ton.

"A lot depends on climate. The difference between Fresno and Napa is climate, not soil type, and other things," Sumner said.  "And some of that climate is changing. So what wine grapes are most suited for a particular area may well change with it."

But unlike tomatoes or alfalfa, wine grapes are perennial crops. Many plants produce for 30 years and some vines are more than 100 years old. That means the plants may live through changing climate, which for California is projected to involve rising temperatures, warmer nights particularly, and threats to water availability.

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Climate change and regulations worry Calif. farmers

(Kathleen Masterson/Harvest Public Media)

In the Midwest, the few degrees of warming has actually benefited agriculture, on average.

But in California – where they grow more than 200 crops, including perennials such as walnuts and apricots – some crops could be adversely affected.

Plus, California farmers also have new climate change regulations to contend with, which worry many growers more than the weather.

But Central Valley wine grape growers aren't too fazed by the climate change predictions.

Aaron Lange of Lange Twins Family Winery and Vineyards in Lodi, Calif., said it's too soon to tell what climate change might bring for the region, but his family already works to make the vineyard as sustainable as possible. 

The motivations are multiple – it’s good for the earth, it's economical and it keeps the vines healthy and productive. The Lange vineyards use drip irrigation, measuring the amount of water in the soil before applying more.  And, Lange said they grow the vines in a way that the plant's leaves form a loose canopy.

"The canopy trellis allows that grape vine to grow up in a certain way, to provide umbrella over fruiting zone, which will then protect  your fruit from sunburn," Lange said. "But we do that regardless of whether going to experience a 1 or 2 degree temp change or not."

That's because the speckled light that filters through the canopy helps grow the highest quality wine grapes possible, he said.

It's impossible to say if the climate changes over the past decades, and future ones, are caused by climate change, said Joe Valente, the vineyard manger at Kautz Farms, also in Lodi.  And the industry changes that's he's seen on his watch haven't stemmed from climate, Valente said.

"The reason our farm has changed is more market driven. Even with the grape industry in Lodi, 20 or 30 years ago everybody was growing Tokays (grapes), but now, there's hardly any," Valente said. "There were 35,000 acres, but we've now switched to Chardonnays and Zinfandel. That's basically driven by the market."

Not only that, Valente said, but some of the grapes they grow aren't necessarily ideally suited to the climate, but they can make it work.

Even with perennial crops, he said, farmers are accustomed to change.  And like farmers across the state, the biggest concern with climate change really the regulations that come with it.

"It seems as though every time you look in another direction, there's a new regulation, something else you have to learn, something else you have to do," Lange said. "So it's a constant struggle to keep up to this. As farmer here we really have to be our own lawyers, our own politicians, our own biologists, our own viticulturists, our own winemakers, our own marketers."

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