Winter tule fog is a dense fog that forms on cool, still nights in California’s central San Joaquin Valley. For many people, it is most well known for the frequent automobile accidents that result when people drive normal speeds with the reduced visibility. But, it has a much more important impact on agriculture.
Many of the crops grown in the valley require a long dormant season in order to produce a quality crop. Tule fog is critically important to inducing the plants to go dormant. It not only chills the plants in the winter, but it also shades them from the sunlight. Both of these actions cause the plants to go dormant. As a result, they store energy and are ready for vigorous growth in the spring time. Without the long dormant period, they won’t have as much energy for growth and the crop yield will suffer. Among the crops that are dependent on this process are almonds, pistachios, cherries, apricots and peaches. As much as 95% of American production of some of these crops come from this area.
Now, a new study, published in the journal Geophysical Research Letters has shown that the amount of winter tule fog has decreased by as much as 46% over the last 30 years due to climate change. This is having an impact on the crop yield. Farmers are trying to deal with the problem by attempting to identify hybrids that can do well without the fog. Another idea is to relocate orchards.
Lower yields and expensive treatments mean higher prices at the supermarket for our food.
One more example of how climate change is costing us money right now.