Climate change could dramatically affect the microclimates that have made California wine country so successful.

You've probably heard of the wines that made Napa and Sonoma famous, like Cabernet Sauvignon or Chardonnay. But what about Negroamaro or Nero d'Avola?

They're wine grapes that are well-adapted to hotter climates – the kind of conditions that California may be facing as the climate continues to warm. But for wineries that have staked their reputations on certain wines, adapting to climate change could be a tough sell.

Talk to any wine lover in California and they'll tell you how lucky they are to live in such rich wine-producing region. Take the recent meeting of the San Francisco Wine Lovers Group at Toast wine bar in Oakland, where the favorites are California Pinot Noir, Russian River Zinfandel, and Napa Cabernet.

In fact, the type of grape – or varietal – is how most of us think about wine.

"That's the big problem," says Andy Walker, a grape breeder in Viticulture and Enology at the University of California-Davis. "We've spent the last 100 years emphasizing varieties and we've really marketed those names very effectively."

Walker is strolling through UC Davis's test vineyard, where hundreds of different wine grapes from around the world are grown. The vast majority are unknown to consumers, because most wineries focus on only a handful of grapes. "Chardonnay, cabernet, merlot, pinot noir – those would make up probably a large percentage," he says.

Those are all French varieties, mostly suited for cool climates. California is warm by comparison and thanks to climate change, it's expected to get a lot warmer. Extreme heat can be the enemy of good wine. "It destroys acidity primarily and it changes color and aromatics," says Walker.

According to a recent study from Stanford University, about two degrees of warming could reduce California's premium wine-growing land by 30 to 50 percent. That could happen as soon as 2040. Water supply is also expected to be an issue.

"I think the interesting thing for me as a breeder is to take advantage of this and say, OK, here's a chance now to change thought and let's actually readapt varieties to California," he says.

Andy Walker walks through UC Davis's test vineyard.

But in many circles, grape breeding is a dirty term, according to Walker.

"Viticulture is the most backward form of horticulture that exists. We use these varieties that haven't been changed for decades, for millennia in some cases. And it really doesn't make any sense."

The problem starts in today's vineyards. If you look at rows of Pinot Noir vines, you aren't just looking at the original varietal. You're looking at clones. That's because vines are grown from a branch that's taken off an existing plant.

"Pinot noir is being propagated year after year after year. This essentially means that grapes have not been having sex very much," says Sean Myles , a geneticist at the Nova Scotia Agricultural College.

He says breeding is key for other crops, since farmers need seeds to plant every year. Wine grapes miss this opportunity to develop adaptability and disease resistance, since vines don't grow from seeds

"That means that we're not allowing the genetic material to be shuffled anymore. That genetic material is now standing still in time. And while the pathogens are evolving, the pinot noir is not," says Myles.

Andy Walker says there's plenty of genetic diversity out there for breeding, if you wanted to make today's varieties more heat tolerant or drought resistant. But there's a very big problem. Once your breed your pinot noir with something else, you can't call it pinot noir anymore.

"The last decision that hardest. Can we market this variety? We know it produces exceptional wine. We know the quality is better. But the next step is can we actually market it," says Walker.

That's a deal breaker for many vineyards, who think consumers won't buy varieties they don't recognize. Walker says looking ahead to climate change, there are already varieties out there today from Italy and Spain that would do well in a warmer California. "We could produce Barbera instead, or Negroamaro or Nero d'Avola from southern Italy and we'd be far better ahead."

These lush reds are popular in Italy but not so well known to Californians. Walker says it'll come down to marketing. "I don't think it's the consumer that's gonna make the shift. They have to be directed."

"I think it's really a pull from consumers," says Nick Dokoozlian, a Vice President at E & J Gallo Winery, the largest family-owned winery in the US. "In most cases, we're responding to consumer demand for a cultivar."

Dokoozlian says Gallo has been testing new wine varieties throughout its vineyards and has found some promising grapes. "The problem is we can't necessarily sell those varieties. Consumers aren't aware of them. The marketing aspect of climate change and the adaptation to climate change, really, the hurdles on the marketing side are much, much more significant."

Since vineyards can last up to 30 years, he says switching varieties is a major financial gamble. "The wine business is an extremely capital intensive business. The financial risk of planting the wrong variety in the wrong place is pretty significant."

Still, given the temperature and water supply changes projected for California, Dokoozlian sees the market shifting eventually. "I'm looking forward to having world-class California Nero d'Avola soon."

I often look at the chemical ingredients in what I buy. I shop at farmers markets for organic produce and use green cleaning supplies. So, it caught me off guard when a friend remarked, "you are so aware of what you eat, why aren't you just as curious about what you drink?" Well, we drink organic coffee but not organic wine. I was worried about sacrificing taste and I just didn't think most vineyards were heavily sprayed with pesticides. Then I learned that wine grapes are the second most sprayed crop in the state. This didn't seem like it could be that good for the farm workers, the Earth, or the consumer. Several studies have found trace amounts of pesticides in wine. They may be at extremely low amounts, but what kind of impact could pesticide residues have overtime?

Armed with a new green cause, I set out to find more information about eco-wines. I learned that organic wine is just one type of green wine — there is also wine made with organic grapes. It turns out I had been drinking some of these wines and enjoying them. The thing is, you can't call it "organic wine" if the wine has added sulfites, a naturally occurring compound. Most winemakers add sulfites to help preserve the wine and make it more stable. If a wine is made from organic grapes but contains sulfites, the world "organic" can only be mentioned as part of the ingredient claim on the back of the bottle. No wonder I didn't know I was drinking wine farmed organically.

It turns out northern Sonoma County and Mendocino county are hotbeds for green wine. In the course of reporting this story, I visited several of these wine makers. Bonterra Vineyards, below Ukiah, has been farming organically since 1987 and now farms one of their ranches, McNab, biodynamically. Their red blend is nicely balanced and tastes very good.

Biodynamic is a novel form of organic farming practice with its roots in France. A biodynamic vineyard is a self-sustaining ecosystem — making organic compost, removing chemicals from the soil and farming with the cycles of the Earth.  Biodynamic has its own international certification. (Here is a list of their certified wines). Just up the 101 from Bonterra is Parducci Wine Cellars. This family run company is farming organic grapes and in some cases, biodynamically. Parducci also claims to be one of the most sustainable wineries in the country.

Sustainable is a squishy term. Sustainable wineries may be running off solar power or doing creek restoration to save spawning salmon but they are not necessarily organic and they are not certified. However, the California Sustainable Winegrowing Program is working toward an industry certification. The idea is to raise the entire industry's practices and help vintners make more eco-friendly choices that often include using less chemicals in the vineyards.

Back to sulfites. This ended up being the main reason for the stigma still associated with green wine. Twenty years ago, green wines were uneven and there were not that many choices. Now, several of these eco-wines are winning high points from the industry. Organic wine can only contain naturally occurring sulfites, under 10ppm. Wines farmed organically must keep the added sulfites below 100ppm. Conventional wine can contain sulfites as high as 300ppm. When I was reporting this story, several folks asked me if I was going to explain why they get headaches from red wine. Isn't it the sulfites? Actually, it is not known why some people get headaches from drinking red wine. It could be the histamines. It doesn't look like it's the sulfites. Less than 1% of the population, according to the FDA, is sensitive to sulfites. The reaction is a respiratory one.

Anyway, if you enjoy wine, I encourage you to think beyond red and white but to consider green, too. To find out more, listen to our radio story and check out our links. Also, green wine pioneer, Paul Dolan together with Parducci has created a green wine handbook which is very helpful.

Listen to the The Politics of Green Wine radio report online.

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In our radio story, we feature the stylishly high tech Vineyard 29 and the Robert Mondavi Winery, but scores of other wineries are using a similar toolbox of technology to help them monitor the soil's water content to grow better grapes. The technology ends up conserving water, too. Remote sensing, ground penetrating radar and satellite technology have helped Mondavi cut back on water use by 30% in recent years.

Winemakers are using some of the same technology that NASA uses to study Mars and engineers use to build hi-rises and freeways. A typical toolbox includes multi-spectral imaging, weather stations, neutron moisture probes, and pressure bombs and there is a plethora of newer technologies in the pipeline. But enough with all the high tech gizmos. How does wine from high tech vines taste? The answer might be found in the success of the winery. Mondavi has won numerous awards over the years and there is a two-year waiting list just to purchase Vineyard 29 wines.

Check out our slide show to see some of these technologies or listen to our radio report on high tech in the vineyards.

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