Like Fruit, Vegetables, and Almonds? Scientists Have Bad News.
Like Fruit, Vegetables, and Almonds? Scientists Have Bad News.
A new study finds that the main source of water for our fresh produce could dry up within our lifetimes.
Tom Philpott
January 1, 2019 6:00 AM
So far, this winter has brought ample snows to the Sierra Nevada, the spine of mountains that runs along California’s eastern flank. That’s good news for Californians, because the range’s melted snow provides 60 percent of the state’s water supply. Anyone in the United States who likes fruit, vegetables, and nuts should rejoice, too, because water flowing from the Sierra’s streams and rivers is the main irrigation source for farms in the arid Central Valley, which churns out nearly a quarter of the food consumed here.
But the Sierra snowpack has shown an overall declining trend for decades—most dramatically during the great California drought of 2012-2016—and will dwindle further over the next several decades, a growing body of research suggests. In the latest, published in the peer-reviewed Geophysical Research Letters journal, Lawrence Berkeley National Laboratory researchers lay out what they call a “future of consistent low-to-no snowpack.” In other words, a new normal wherein the robust snowpack developing this year would be an almost unthinkable anomaly.
To get a picture of what water planners can expect in the coming decades, the team focused on the headwaters feeding 10 major reservoirs designed to capture snowmelt from the Sierra each year. Using averages from 1985 to 2005 as a baseline, they applied nine different climate models. They assumed global greenhouse gas emissions would continue rising at present rates —that is, a “business as usual” scenario with no effective global deal to cut greenhouse emissions and no major technological breakthroughs.
The results: By mid-century (2039–2059), the average annual snowpack will fall by 54.4 percent compared to the late-20th century baseline. By the time today’s teens are in their 70s, it will be 79.3 percent beneath the old standard. To analyze massive amounts of water, planners think in acre-feet—the amount needed to submerge an acre of land by one foot. At the end of the last century, the Sierra Nevada captured an average of 8.76 million acre-feet. By mid-century, they project, the average will fall to 4 million acre-feet; and by century’s end, 1.81 million acre-feet.
The Central Valley Project—a federally run network of dams, reservoirs, and canals that waters about a third California’s irrigated farmland and provides water and electricity to millions of urban users, all from snow melt—could become a what economists called a “stranded asset” in such a scenario: a multi-billion dollar public investment that lacks sufficient water to perform its tasks.
more...
https://www.motherjones.com/food/2019/01/like-fruit-vegetables-and-almonds-scientists-have-bad-news/
= new reply since forum marked as read
there is an article about water shortage in California... almonds and fruit are usually to culprit... animal agriculture uses more 
"California Governor Jerry Brown has been talking tough about California’s growing drought crisis. In January he declared a state of emergency saying, “I’m calling on all Californians to conserve water in every way possible,” and just last week he announced that we are “in a new era” of drought severity. But while his rhetoric was rightfully alarming, his solution, a mandatory 25% reduction in household water consumption,
Bring fresh drinking water down to the western states from Canada and Alaska.
I think they have to repair the leaks in the pipes first though.
Which works fine for those of us that have houses and land. And maybe a green thumb too 
I’m adding 2-3 edible perennials a year. Sometimes a fruit tree, sometimes a veggie. This year it’s kiwi, evergreen huckleberry and asparagus (I already have asparagus; I’m expanding my bed significantly.) Last year it was a fig tree and goumi bushes. I also buy open pollinated seeds if I can.
I grow most of my veggies from seed. I’m hoping for a greenhouse in the next couple of years. For now I grow winter greens in the basement under lights until I have to start the summer seedlings.
