Climate Change Threatens California Cornucopia

Climate change will impact nationwide food supplies due to increased temperature variation and reduced water supplies.

Featured Photo Credit Henrik Johansson

A paper recently released by Agronomy, an independent, open access, journal published by MDPI details the impact climate change could have on California agriculture. I can visualize all of the eyes collectively rolling as they read the opening line. But hear me out.

The paper, titled “Climate Change Trends and Impacts on California Agriculture: A Detailed Review, describes the myriad issues facing California agriculture as the impacts of climate change are felt.

The rest of the nation may look down on California as a collection of left-wing pinko-commies while simultaneously enjoying the literal fruits of our labor (well, really the labor of hard-working farmers and farm-workers). California produces more than a third of the country’s vegetables and two thirds of the fruits and nuts. 50% of the fruits and nuts consumed in the US are grown in the central valley. So, the next time you grab a handful of almonds, eat a nectarine, or drink a glass of Chardonnay, chances are the source was California. It does all of this on a little more than 1% of the nation’s total farmland. The collapse of California agriculture would have an impact nationwide.


Picture Source KQED Television

However the central valley is home to a majority of the Republicans in the state. In a state that is overwhelmingly Democratic, several central valley counties voted for Trump over Clinton, and central valley politicians routinely deny the evidence for human caused climate change.

This seems ironic in that the segment of California’s economy that will be most directly impacted by climate change is agriculture. Climate change, or Global Warming, is in the process of changing the historical water cycles and temperature extremes and, if the models are correct, will impact California’s production of food for the nation.

California is all about water. The good news is precipitation models show that overall rainfall amounts in California will increase about 0.20 inches, mirroring the nation as a whole. The bad news is, “The variability of precipitation in California is a unique phenomenon, implying that such unpredictability is more notable in the state than other parts of the West Coast and the country as a whole.” This was the paper’s way of saying our periodic droughts play havoc with the water supply now and that it will get worse as temperatures rise.

Temperature rise is also impacting water storage and distribution strategies. Almost all California rivers are dammed to provide water storage and/or power. They were built in an era when 80% of the water was deposited in the Sierras as snow and then was slowly released during the spring and early summer snowmelt. This cycle is changing. Higher temperatures mean that more of this water comes as rain. Dams and reservoirs are now filling sooner and may in the future have to release water early, maybe too early in the growing season. Models predict that there may be as much as a 65% reduction in the snowpack by the end of the century.

So the combined effects of temperature variability and water supply instability impacts at least 8 of the 20 major permanent crops. These include yield reductions in “almonds, wine grapes, strawberries, hay, walnuts, table grapes, freestone peaches, and cherries”.

Many of California’s fruit and nut crops require cold winter temperatures for optimum yields. “The lack of adequate chilling hours can delay pollination and foliation, reducing fruit yield and quality.”So the elevated temperatures expected during winter reduce crop yields. All of this means less food and wine will be produced and shared with the nation. In fact, models predict that some of the main tree crops now grown in the central valley will no longer be viable at the end of the 21st century.

The paper continues to detail other impacts like an in crease in plant desease, reduction in grazing grasslands, etc. But you get the point, climate change will impact our food supply. This is not to say that there won’t be enough food, just that we may have to change our eating habits, and maybe drink less wine.


Acknowledgments: This paper was supported by the University of California Office of the President, supported Carbon Neutrality Initiative funding and by the University of California, Division of Agriculture and Natural Resource (UC ANR).

Published in Agronomy

Climate Change Trends and Impacts on California Agriculture: A Detailed Review

Tapan B. Pathak, Mahesh L. Maskey , Jeffery A. Dahlberg , Faith Kearns , Khaled M. Bali,and Daniele Zaccaria

Correspondence:; Tel.: +1-209-228-2520

Received: 9 Nov 2017; Accepted: 21 Feb 2018; Published: 26 Feb 2018

Agronomy 20188(3), 25;

Agronomy (ISSN 2073-4395; CODEN: ABSGGL) is an international, scientific, open access journal published monthly online by MDPI.

About MDPI – A pioneer in scholarly open access publishing, MDPI has supported academic communities since 1996. Based in Basel, Switzerland, MDPI has the mission to foster open scientific exchange in all forms, across all disciplines. Our 199 diverse, peer-reviewed, open access journals are supported by over 35,500 academic editors. We serve scholars from around the world to ensure the latest research is freely available and all content is distributed under a Creative Commons Attribution License (CC BY).


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