Pandemic Diary Entry #76
February 8, 2021
My favorite flower is the peony and one of my favorite flowering trees is the Dogwood. I can not grow either in San Francisco due to the lack of winter chill. The term is rather complicated and relies on a series of things, but for simplicity’s sake we will define winter chill as a period of cold temperatures above freezing and below a threshold temperature that varies with each plant species.
The lack of winter chill is beginning to affect the farming industry of California. If California were a country it would rank around tenth in the value of goods and services produced. California also is the number one state in the US in farm income. About 73% of the state’s agricultural income is derived from crops with the other 27% from livestock.
California has, in the neighborhood of 77,500 farms with 9.4 million acres of irrigated cropland generating around 50.5 billion dollars. California produces over 1/3 of the country’s vegetables and 2/3 of its fruits and nuts. California crops consist of 400 different items, some of which are not produced anywhere else.
The nuts and fruits consumed in the United States and grown in California, include almonds, pistachios, walnuts, grapes, cherries, citrus, apricots, dates, figs, kiwi fruit, nectarines, prunes, and olives. California is also the leader in the production of avocados, grapes, lemons, melons, peaches, plums, and strawberries.
Climate change is preparing to wreak havoc on those crops.
Scientists are working hard to adapt crops to the coming changes but it is not an easy task and may prove to be nigh on impossible.
Tree fruits, which include nuts, rely on climate to initiate hibernation and all the steps leading to a crop. In late summer, buds emerge and they, along with new twigs grow until fall temperatures tell the tree to go dormant. At that point, the tree needs a given number of days where the temperature sits between freezing and 45 degrees. Once it has received those hours it will begin to bud as temperatures rise. If this growth has progressed too far prior to going to sleep, the buds, which are future fruit, are vulnerable to freezing. Trees that receive an insufficient amount of chill time, bloom sporadically and poorly. Not only does this compromise the quality of the fruits and nuts but the trees can become so stressed they die.
Chilling requirements vary, with almonds needing between 400 to 700 hours, walnuts between 400 and 1500 hours, and cherries between 600 to 1400 hours.
In 2009 the California Department of Food and Agriculture determined that in 1950 the Central Valley could rely on between 700 and 1200 chilling hours, but by 2000 that had declined as much as 30% in some areas. By the middle to the end of this century, it is projected that the changed climate will no longer be conducive to growing some of California’s main tree fruit crops, resulting in serious economic, dietary and social consequences.
It isn’t just chill days or hours, the right temperature is also critical. Warm weather in the early part of the year can reduce the almond yield, a warm summer can reduce the peach yield, and hot winter days can cause sunburn. Recently, during low-chill winters in California, male, pollen-bearing pistachio trees bloomed out of sync with the female nut-bearing varieties, reducing the crop. Extreme swings in weather will also affect yield as it varies between drought and flooding. Combating pests and diseases may become a large problem as well.
Central Valley temperatures are predicted to rise five to six degrees Fahrenheit by the end of the century, while periods of extreme heat are expected to more than double to 50 days a year or more over that time. Irrigation water is becoming saltier as well, due to excessive groundwater extraction.
For decades farmers have been sucking up groundwater at unsustainable rates. On average, agriculture makes up about 80% of commercial and residential water consumption. During the drought period of 2012–2016 deep irrigation wells lowered the groundwater levels, putting it out of reach for the shallower wells that provide people drinking water. This excessive pumping helped to sink the San Joaquin Valley by as much as 20 feet. The Central Valley is on target to sink 30 feet by 2030. The water being pumped out of the ground today is 20,000 years old and the act of pumping it out is consuming about 5% of the state’s energy .
According to the U.S. Geological Survey, Californians drained about 41 trillion gallons of groundwater from the Central Valley between 1920 and 2013. This has done permanent damage. Once the land has sunk it remains permanently compressed, so these aquifers, when they are replenished, hold less water than they once did. Even if we stopped pumping water today it would take 50 years to replenish what we can, into the aquifer. This sinking has other ramifications, some put an estimate to the state of more than $1 billion to fix just some of the damage, such as sinking bridges, cracking canals and buckling highways.
Farmers and scientists are working on the issue but many worry that breeding for a more resistant fruit can not keep up with the rapid changes in climate. It takes between 15 to 30 years to bring a new commercial apple or peach variety to market. Presently the genetic diversity of nut trees in California is very low and they are less adaptable to climate changes, adding to the difficulty.
This leaves farmers in a situation of having to continually move either northward or to higher elevations to produce the same crops, hardly a viable answer.
This problem is not limited to California. The industry as a whole is a key contributor to climate change, it generates ten to fifteen percent of greenhouse gas emissions
All types of crop and livestock production produce various greenhouse gases. The production, storage, and transport of both agricultural products and the products it takes to farm (feed, fertilizers, pesticides, etc.) result in the production of not just CO2 but other greenhouse gas emissions as well.
While the Biden administration has put climate change front and center, and that includes the agricultural sector, they must be smart about it.
Government subsidies to farmers are obscene. Farm subsidies to date amount to a $52 billion handout, which constitutes 44 percent of net farm income. These subsidies insulate farmers from the financial risk of climate change, leaving little incentive to adapt. The good news is, most of the agricultural industry is on board. Large food companies, environmentalists, and even former government officials are pushing to mitigate agriculture’s role in climate change. Suprisingly even long-time climate change deniers like the American Farm Bureau Federation, have joined the fray. Industry groups have formed the Climate Alliance and produced a report highlighting farming practices that can help in lessen agriculture’s impact on climate change. It is a start.
Global warming is real, and its devastating effects are already upon us. It is time for a new way of thinking and doing on everyone’s part.
San Francisco weather: 53 Degrees and cloudy
NYSE DOW compared to one year ago: +2196
COVID cases in the US: 27,615,251
Deaths from COVID in the US: 474,975
OED word of the day: pip emma - Post meridiem, afternoon
Days since Shelter In Place was initiated: 329
Reading: Women in the Dark: Female Photographers in the US 1850–1900 by Katherine Manhorne
My Black and White Picture of the Day
Something Silly From the Internet: