Luedeling's dire prediction was included in a story about new UC Davis research that shows winter chill hours in the San Joaquin Valley could decrease 60 percent from 1950 levels by mid-century and by as much as 80 percent by the end of the century. The reduction in winter chill, a vital component of many fruit and nut tree's growth cycle, means the valley may ultimately become unsuitable for many of the crops currently grown there. The story, written by Margot Roosevelt, was prompted by a release issued by UC Davis news service about research being published today in the online journal PLoS One.
The UC Davis study builds on a 2007 paper by UC Berkeley scientists Dennis Baldocchi and Simon Wong that predicted dramatic drops in winter chilling hours, the Time story said.
"The irony is, just as the populace is getting more in tune with eating better, eating local, our wonderful fruit industry may be negatively affected," Baldocchi was quoted in the Times.
The story also appeared in the San Francisco Chronicle and on the Discovery Channel news Web site.
The earth's climate is changing.
Escaped nitrogen from agricultural production has "huge potential to contribute to climate change," according to the director of the Agricultural Sustainability Institute at UC Davis, Tom Tomich. He was quoted in "The Smog Blog," written by Mark Grossi of the Fresno Bee, in a post about $2.8 million in grant funding ASI received to research agricultural nitrogen. The story appeared in his blog last week and on the front page of the newspaper's Local News section yesterday.
According to an ASI news release announcing the new funding, many people, including politicians. are unaware that escaped nitrogen from agricultural production affects climate change and air, water and soil quality.
Earth's atmosphere is 78 percent nitrogen by volume, according to the Wikipedia entry on the chemical element. And in fact, "Mike D." commented on Grossi's blog posting, "I'm a bit confused as to how nitrogen could be a greenhouse gas when it already exists in abundance in the atmosphere."
This confusion perhaps underscores the need for more research and extension efforts on the topic. According to the ASI news release, data on agricultural nitrogen pollution are limited, and some nitrogen pollution forms are difficult to monitor. Measurements can be labor-intensive and expensive and are influenced by variables such as weather conditions, irrigation timing and method, and crop-specific fertilization practices.
I trust that, as the ASI's research is conducted and results are publicized, much more information about the role of agricultural nitrogen in global warming will become widely available.
Under any of six models of climate change, in 100 years there will be no new trees in Joshua Tree National Park and a significant number of existing trees will be dead, according to a recent Riverside Press-Enterprise story. The climate models, developed by Ken Cole, a biologist and geologist with the U.S. Geological Survey in Flagstaff, Ariz., and plant ecologist Kirsten Ironside of Northern Arizona University, suggest a temperature increase of seven degrees.
Joshua Trees were prolific and widespread 11,000 years ago, Cole told newspaper reporter Janet Zimmerman. Their seeds were carried long distances from Mexico to Nevada in the dung of the Shasta ground sloth. Now, seeds are transported only short distances by rodents.
Climate change is expected to combine with other human impacts to threaten Joshua Trees. Factors mentioned in the Press-Enterprise article include:
- Non-native grass species, such as red brome and cheatgrass, are transported along roads by passing cars.
- The non-native grasses are fertilized by nitrate and ammonium deposited in the soil by car emissions. Edith Allen, a UC Riverside professor of plant ecology, has found that the levels of those chemicals in the park are 15 to 30 times higher than those in an undisturbed ecosystem.
- Dirt patches that separated native plant species are being replaced with a continuous carpet of non-native grass.
- Wildfire is increasing in frequency and intensity as the continuous bed of tinder dry grass carries fire long distances from plant to plant.
A possible bright side: Joshua Trees are taking root in areas to the north, such as Tonapah, Nev., where none existed a century ago because it was too cold.
JoshuaTree
Reports about climate change in the current issue of California Agriculture journal are taken with a brave face by Kings County farmers and officials, according to a story published in the Hanford Sentinel. Reporter Sean Nidever provided highlights in the newspaper of the research presented in the UC ANR's 50-page publication titled "'Unequivocal' How climate change will transform California."
Despite the fact that Nidever reported that the county's agricultural industry could face "tough times," Kings County farmers and agricultural officials "declined to panic," the story said.
"Really all that we can say is that farmers would have to adapt, like with any other issue," the article quoted Diana Peck, Kings County Farm Bureau executive director.
One result of climate change predicted in the journal is that more precipitation will fall in California as rain, overwhelming reservoirs and forcing water to be released at times when agriculture can't use it. At least two local growers said that makes a good case for building more reservoir capacity.
"If their projections are correct and the climate is indeed warming, then this report makes the best argument I know of in favor of building water storage, reducing regulatory barriers on agriculture and investing in genetic technology," dairy operator Dino Giacomazzi told the reporter.
Nidever also wrote a separate article, published yesterday, that touched on another issue raised in the journal, dairy greenhouse-gas emissions. The reporter apparently spoke to the journal article's author, UC Davis Cooperative Extension livestock air quality specialist Frank Mitloehner, who told him dairies will soon face regulation for greenhouse gases under California's landmark greenhouse gas reduction law passed in 2006.
Possible solutions to the dairy air emission problem presented in the Sentinel article are the development of specially engineered food and probiotics that will reduce the amount of methane cows belch and capturing dairy cow emissions to generate energy.
The Bay Area National Public Radio affiliate KQED posted "reporter's notes" on the Quest portion of its Web site yesterday featuring comments from UC Berkeley fire ecology specialist Max Moritz about recently published research that predicts changes in world wildfire patterns due to climate change. Quest is a KQED multimedia series exploring Northern California science, environment and nature.
In the written notes, reporter Craig Miller explained that Moritz and a team of researchers found that climate change won't cause a rise in wildfire everywhere in the world.
In audio interview excerpts, Moritz himself says that different climatic variables -- such as precipitation patterns and temperatures -- around the world mean climate change will have different effects on wildfire patterns. Most places, including California, will see increases in wildfire activity; other areas, like the Pacific Northwest, may see fewer, less intense fires.
"(The fact) that just in the next couple of decades we’re going to see very extensive and rapid shifts in fire activity, I think that’s a bit of a surprise," Moritz said.
Max Moritz
