Things heat up in the nation's produce basket: Tree crops like apples, cherries, pears, walnuts and almonds rely on a chilly winter to set the stage for a productive spring and summer. But in a study released today, UC Davis scientists report that climate change is chipping away at the number of winter chill days available to tree crops in California's Central Valley, jeopardizing the future of orchards that feed consumers around the country.
In 1950, says the report, half of the Central Valley was suitable for growing tree crops. Today, only 4% of the valley gets enough chilly days in winter to produce well in the summer and fall. By the end of this century, they predict that virtually none of the valley's land area will be tree-fruit friendly.
The technological optimists are out in force on this one, of course, hoping that new breeds of tree crops can be developed to require fewer cold days. Others suggest increasing the use of, um, "rest-breaking chemicals" that can compensate for a lack of cold days. (Don't ask us how.) But UC Davis researchers aren't so hopeful. "The main walnut breeder at UC Davis is retiring," says one of the study's authors. "After that, funding will be short."
Take-home message? "Climate change is not just about sea-level rise and polar bears," says the lead author of the study. "It is about our food security. Climate change may make conditions less favorable to grow the crops we need to feed ourselves." (LA Times)