Fruit and Nuts

The Annapolis Valley is a fruit growing area so we suppose that with all the worry over global warming this study from California might be of concern.

Winter chill, a vital climatic trigger for many tree crops, is likely to decrease by more than 50 percent during this century as global climate warms, making California no longer suitable for growing many fruit and nut crops, according to a team of researchers from the University of California, Davis, and the University of Washington.

In some parts of California’s agriculturally rich Central Valley, winter chill has already declined by nearly 30 percent, the researchers found. [Source]

Now before our local fruit growers get too hot and bothered we point out that global warming as commonly understood may not be the culprit in this effect as assumed in the study.   Human intervention may be at work  alright, not via CO2 production but because of local land use policies, in this case,  irrigation. Anthony Watts at Watts Up With That has pointed to another study which fingers a different cause which may affect temperatures locally, including winter chill.

The same irrigation that turned California’s Central Valley from desert into productive farmland is probably also to blame for summer nights there getting noticeably warmer.

Irrigation has turned much of the San Joaquin Valley’s dry, light-colored soil dark and damp, says Dr. John Christy, director of the Earth System Science Center at The University of Alabama in Huntsville (UAH). While the valley’s light, dry desert ground couldn’t absorb or hold much heat energy, the dark, damp irrigated fields “can absorb heat like a sponge in the day and then, at night, release that heat into the atmosphere.”

That means the region’s summer nighttime temperatures don’t get as cool as they did before irrigation came along.

Computer models used to forecast climate change also typically predict that in California the effects of global warming due to increased carbon dioxide levels should warm temperatures in the Sierra Nevada mountains faster than in the nearby valleys. The UAH study, however, found that from 1910 to 2003 night and daytime temperatures in the nearby mountains did not climb.


HT Watts up with that.

Irrigation may not be as widespread in the Annapolis Valley (and certainly not necessary THIS summer so far!) but possible consequences are worth noting.

The UC Davis study was funded by the California Department of Food and Agriculture and The Nature Conservancy. One wonders why they had to “rediscover” warming already found by the Alabama study in 2006. Perhaps they didn’t like the irrigation cause scenario. American tax dollars at work.

Speaking of Fruit and Nuts from California:


Perhaps this sort of input is what our Town worthies fear if they allow comment?


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