Will wreak havoc on California agriculture
The California is the breadbasket of the US, producing more than two-thirds of the country’s fruits and nuts, including almonds, pistachios, oranges, apricots, nectarines and prunes, and more than a third of its vegetables, including artichokes, broccoli, spinach and carrots. It’s all valued at more than $50 billion a year.
That’s the assessment of a recent paper by a University of California team led by Tapan Pathak of UC Merced. But the researchers focused on a different aspect of California agriculture: You can kiss much of it goodbye because of climate change, latimes.com reported.
The paper, published in the journal Agronomy last month, is the most thorough review of the literature on the regional impact of climate change in recent memory. It makes grim reading.
Among the chief manifestations of climate change will be changes in precipitation patterns, leading to more drought and more Àooding, and spottier water storage. Generally warmer temperatures, not to mention more frequent and severe heat waves, will reduce yields of strawberries and walnuts; shorter chill seasons will make vast areas no longer suitable for chestnuts, pecans, apricots, kiwis, apples, cherries and pears. Plant diseases and pests will move into regions where they haven’t been a problem before.
The increased rate and scale of climate change is beyond the realm of experience for the agricultural community.
Few crops will escape the dire effects of the transformation. Seasonal chilling is necessary to break some crops out of dormancy and launch pollination and Àowering. By the end of this century, according to a study cited by the UC paper, the shrinking winter chill period will reduce the acreage of the Central Valley suitable for chestnut, pecan and quince by 22 percent, and for apricot, peach, nectarine and walnut by more than half. By 2000, only four percent of the Central Valley was suitable for apples, cherries and pears, but none of that will be left by 2060 under almost any climate change scenario.
Put it all together, and the prospect is for a dramatic change in the mix of California produce and overall output. The UC paper foresees a decline of more than 40 in avocado yields, and as much as 20 percent in almonds, table grapes, oranges and walnuts.
Disruption is already evident with some crops in some regions, the paper notes— in truth, dealing with natural variations in weather always has been the hallmark of California farming — but that’s nothing compared to what lies ahead.
“The increased rate and scale of climate change,” the researchers say, “is beyond the realm of experience for the agricultural community.”
In terms of which areas might be affected the most, “it is hard to point out a single region,” Pathak said, in part because California is a huge state comprising at least two large and distinct regions, north and south.
“Central Valley chill-sensitive perennial crops, especially the ones that require a higher number of chill hours, are vulnerable to climatological changes,” Pathak said.
“Heat-sensitive crops, such as strawberries and vegetables, drive vulnerability in coastal areas. Heat-stress-related vulnerability would greatly impact desert regions.”
California hasn’t been blind to the potential effects of climate change. Indeed, the UC paper tracks closely with the ¿ndings from a consortium on long-term impacts convened by the Department of Food and Agriculture in 2013. The state has been on the forefront of water and energy conservation, on the move toward renewable energy sources and on the reduction of greenhouse gas emissions.
Awareness of the consequences of inaction may help to explain why California Governor Jerry Brown has emerged as a leader in the ¿ght against climate change. He understands the economic devastation that will result from continued climatic warning, as well as its impact on food security and health.