And they worry that the "mega droughts" typical of California's earlier history could come again.
Related: California says it won't be able to fill water demand
Through studies of tree rings, sediment and other natural evidence, researchers have documented multiple droughts in California that lasted 10 or 20 years in a row during the past 1,000 years — compared to the mere three-year duration of the current dry spell. The two most severe mega droughts make the Dust Bowl of the 1930s look tame: a 240-year-long drought that started in 850 and, 50 years after the conclusion of that one, another that stretched at least 180 years.
"We continue to run California as if the longest drought we are ever going to encounter is about seven years," said Scott Stine, a professor of geography and environmental studies at Cal State East Bay. "We're living in a dream world."
California in 2013 received less rain than in any year since it became a state in 1850. And at least one Bay Area scientist says that based on tree ring data, the current rainfall season is on pace to be the driest since 1580 — more than 150 years before George Washington was born. The question is: How much longer will it last?
A megadrought today would have catastrophic effects.( I really wonder if this is pending, it is closer than anyone wants to believe?)
California, the nation's most populous state with 38 million residents, has built a massive economy, Silicon Valley, Hollywood and millions of acres of farmland, all in a semiarid area. The state's dams, canals and reservoirs have never been tested by the kind of prolonged drought that experts say will almost certainly occur again.
Related: Water war fought underground
Stine, who has spent decades studying tree stumps in Mono Lake, Tenaya Lake, the Walker River and other parts of the Sierra Nevada, said that the past century has been among the wettest of the last 7,000 years.
Looking back, the long-term record also shows some staggeringly wet periods. The decades between the two medieval megadroughts, for example, delivered years of above-normal rainfall — the kind that would cause devastating floods today.
The longest droughts of the 20th century, what Californians think of as severe, occurred from 1987 to 1992 and from 1928 to 1934. Both, Stine said, are minor compared to the ancient droughts of 850 to 1090 and 1140 to 1320.
What would happen if the current drought continued for another 10 years or more?
Without question, longtime water experts say, farmers would bear the brunt. Cities would suffer but adapt.
Water and drought is the talk in the west. Now it is making our national news, and for good reason.
What do you think is the solution to their huge, looming problem?
Ed
Whatever it is, it will have to be sustainable. The first thing that comes to mind is that there are trillions of gallons of water bordering California, it just needs to have its salt removed. Another partial solution is that the Pacific Northwest has a lot of water to spare, and most of it does not travel far or do much good, going almost directly into the ocean. But I don't know how much "spare" water they have exactly. Most of the electricity in Washington is renewable from hydro, would diverting some of this water to California affect hydro or the environment?
ReplyDeleteOur industry uses millions of tons of chlorine, mostly from mined rocksalt, so sea salt from desalinated water could easily supply that demand and provide drinking water everywhere in the world with the appropriate network of pipelines, just like we have pipelines for natural gas or oil across whole continents. Water is fast becoming just as precious a commodity. We'll need to step up even more if we want water for irrigation, but I don't see that we have a choice. Ground water is disappearing faster than it replenishes, creating unstable soil in the process, as the pumped water in the soil interstices is not replaced by anything that can take its place, maybe not even air. Drought or global warming certainly play a part in this problem, but mostly it's the higher productivity of agriculture that's required to feed an increasing population that depletes the aquifers.
I read some time ago an interesting accounting of the water trade. Basically, all the food you import, like wine from Chile or tomatoes from Mexico is a displacement of water between countries, and a lot of it: Not just from the actual water content in the product, but also the water that it required to be grown or raised. Even dry grain actually offsets the water balance between countries. Think about it next time you sell a lot of soybean to Japan, you're exporting American water too. A single bushel of corn requires 2,500 gallons of water in Colorado. Even the water that comes from rain is not free, as it could have been put to some other purposes, like replenishing the aquifer.
Good comments,Chimel, but the tiny bit of water in dry grain won't matter!
ReplyDelete