Friday, Sep 28 2012 07:00 PM

Volatile weather creates dramatic changes for California farmers

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    By Serene Fang/ California Watch

    John Duarte, president of Duarte Nursery near Modesto, is breeding plants for elevated levels of heat and salt, which researchers say are symptoms of climate change.

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  2. 2 of 4

    By Serene Fang/ California Watch

    A lab worker at Duarte Nursery prepares clones for breeding in an agar solution.

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  3. 3 of 4

    By Serene Fang/ California Watch

    In response to rising salinity levels, Duarte Nursery is breeding clones of pistachio plants for salt tolerance.

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  4. 4 of 4

    By Serene Fang/ California Watch

    Almond trees grown by farmer Barat Bisabri show signs of poisoning by exposure to salt. Rising salinity levels in irrigation water has farmers alarmed.

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BY MARK SCHAPIRO Center for Investigative Reporting

Ten miles outside of Modesto, in the farming town of Hughson off Highway 99, the Duarte Nursery is at the front line of dramatic changes under way in California's immense agriculture industry.

The family-run nursery, founded in 1976, is one of the largest in the U.S., and there's a good chance the berries, nuts and citrus fruits eaten across the West began their journey to market as seedlings in Duarte's 30 acres of greenhouses, labs and breeding stations.

The nursery's owners have built a thriving business using state-of-the-art techniques to develop varieties adapted to the particular conditions and pests California farmers face.

These days, according to John Duarte, president of the nursery, that means breeding for elevated levels of heat and salt, which researchers say are symptoms of climate change -- even if Duarte doesn't necessarily see it that way.

"Whether it's carbon built up in the atmosphere or just friggin' bad luck," he said, "the conditions are straining us."

The cause of Duarte's woes might be in dispute among farmers in California's $31 billion agriculture industry. But the symptoms are clear. From the vast fields of fruits and nuts in the Central Valley to the wineries of Napa and Sonoma, the increasingly volatile weather is altering the fundamental conditions for growing food, California's largest industry.

Farmers are in many ways at the front line of climate change. They conjure food from soil, sunlight and water -- which are profoundly affected, scientists say, by climate change. Stresses have emerged across the state as water supplies tighten. Rain is coming at unexpected times. Winters aren't getting cold enough. And salt from the rising ocean is making its way into Central Valley water.

More risk factors

Climate change already has cost farmers money. In the Central Valley, some growers are paying more for seeds designed to withstand the new extremes.

At the nurseries and colleges in what Duarte calls "the Silicon Valley of agricultural innovation," these changing conditions have forced botanists to look for varieties of almond, pepper, citrus, cherry and other crops resistant to drought and salt.

Other interests also are bracing for dramatic change. The crop insurance industry is calculating potential billion-dollar losses from extreme weather conditions, as well as floods and fires that occur in their wake. Climate change could join the ranks of earthquake and hurricane insurance as a special -- and expensive -- problem for insurers.

Over the past 20 years, there has been more than $500 million in crop losses from heat waves, floods and ill-timed rainstorms in the agricultural counties of San Joaquin, Merced, Kings, Kern, Napa and Sonoma, according to a study last year by Stanford University researchers.

"Compared to 20 or 30 years ago, farmers are recognizing a lot more risk factors in climate events," said Jeff Yasui, director of the U.S. Department of Agriculture's Risk Management Agency office in California, which handles crop insurance in the state.

Climate and agriculture scientists predicted much of this. Charles Kolstad, an environmental economist at UC Santa Barbara, said California agriculture is being hit with a trifecta of converging forces prompted by climate change: longer seasons of extreme heat, shorter cold seasons and dwindling water supplies.

Climate scientists believe the Earth's average temperature will rise at least 2 degrees in the next four decades -- their most conservative estimate. Along the way, the yields of citrus crops in the San Joaquin Valley are expected to drop about 18 percent, grapes about 6 percent, and cherries and other orchard crops about 9 percent.

Those crops -- accustomed to the cooler edges of California's climate -- are showing declining yields already, according to the USDA's National Agricultural Statistics Service. That could mean higher prices for consumers as the supply shrinks. This summer's record droughts in the Midwest also prompted the USDA to predict a rise in prices driven by devastated yields for corn and soybeans, the primary food for chicken and cattle nationwide.

Less water

If California's water crisis persists, seasonal vegetables and fruits also will be dramatically affected. Some already are.

Much of the southern Central Valley, spreading along Interstate 5, is now a patchwork of fallow fields, according to Gayle Holman with the Westlands Water District in Fresno. Thousands of acres that once grew onions, tomatoes, melons and other crops have been set aside by farmers who can no longer obtain, or afford, water -- a scarcity, scientists say, that is significantly due to the dramatic shifts in the timing of rainfalls in the state.

Like just about everything having to do with climate change, the consequences unfold like a sequence of trapdoors. First, there's the temperature, a jagged progression over the past decade of unusual highs and lows occurring at times of the year that can debilitate growing crops.

Then there's water. California's water sources are caught in a pincer: More water is needed at a time when less water is being delivered into the canals carrying it from the north to the agricultural regions in the south.

A precipitous drop in snowfall has led to declining water runoff in the San Joaquin and Sacramento rivers in the spring and summer months, when it's central to irrigation in the valley. Over the past century, the state Department of Water Resources has measured a steady 10 percent decline in runoff from April to July. In recent years, however, the rate has accelerated to as much as 20 percent.

Farmers in the valley generally blame the drop-off in water on the 2007 state Supreme Court decision affirming the need for water to preserve Pacific smelt and other endangered species.

A study by the Public Policy Institute of California, however, concludes that the roughly 300,000 acre-feet of water diverted to comply with the Endangered Species Act constitutes no more than 20 percent of the reduced water flow to the valley.

Rather, the overall pool of water is shrinking.

"The water that used to exist is now coming earlier in the year," said Francis Chung, chief of the Modeling Support Branch for the Department of Water Resources. "So there's less water to distribute (to the valley) during the summer."

New salt sources

Another growing problem has been rising sea levels associated with climate change. The San Francisco Bay, according to a recent National Academies of Sciences assessment, is projected to rise by as much as 18 inches, and potentially triple that by the end of the century. Those inches translate into waves of new salt sources lapping into the delta.

Less water channeled into the delta from the Sierra means less available freshwater to dilute the onrush of salt, which has been pushing steadily eastward.

A study by UC Davis estimates that if salinity continues to rise at the current rate, by 2030, the financial costs to the Central Valley could be huge: as much as $1 billion to $1.5 billion a year in decreased agricultural activity, amounting to some 27,000 to 53,000 jobs lost.

Daniel Cozad, executive director of the Central Valley Salinity Coalition, a group of local farmers, businessmen and government officials, said some farmers in the western valley are being forced to adapt by switching from salt-sensitive crops like strawberries and avocados to less sensitive -- and less profitable -- crops like alfalfa and wheat.

"Unfortunately," Cozad said, "the higher the value of the crop, the more sensitive it is to salt."

This story was produced by the nonprofit Center for Investigative Reporting, the country's largest investigative reporting team, in collaboration with KQED public radio. Mark Schapiro can be reached at

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