Original post:
Two quick points:
1) The Great American Desert was called that for a reason. The weather of the U.S. over the last 150 years is an anomaly in the longer history.
2) The subsidization of row crops, corn in particular, is a political decision that severely distorts investment and thus nutrition outcomes.
From Mother Jones:
The end of cheap fruits and veggies draws nigh. Here's why.
When people tell you to "eat your veggies," they're really urging you to take a swig of California water. The state churns out nearly half of all US-grown fruits, vegetables, and nuts; farms use 80 percent of its water. For decades, that arrangement worked out pretty well. Winter precipitation replenished the state's aquifers and covered its mountains with snow that fed rivers and irrigation systems during the summer. But last winter, for the third year in a row, the rains didn't come, likely making this the driest 30-month stretch in the state's recorded history. So what does the drought mean for your plate? Here are a few points to keep in mind:For more on past climate history, a topic we'll be posting more on over the next couple decades, here's a primer that makes no major science mistakes. From Prairie Fire:
The abnormally wet period when California emerged as our fresh-produce powerhouse may be over. B. Lynn Ingram, a paleoclimatologist at the University of California-Berkeley and author of The West Without Water, says the 20th century was a rain-soaked anomaly compared to the region's long-term history. If California reverts to its drier norm, farmers could expect an average of 15 percent less precipitation in the coming decades, and climate change could exacerbate that. Less rain means more irrigation water diverted from already dwindling rivers—bad news for river fish such as the threatened delta smelt. Wells won't save the state, either: Farmers are already pumping the groundwater that lies deep under their farms much faster than it can be naturally recharged.
Cotton out, orchards in. California farmers have increasingly turned toward orchard crops like nuts, grapes, and stone fruit. That's because those crops bring more return for the water invested than lower-value row crops like cotton, rice, and vegetables. But they also make for less flexibility: A broccoli farmer can let land lie fallow during a drought year, but an almond farmer has to keep those trees watered or lose a long-term investment.
California will keep getting nuttier. According to US Geological Survey hydrologist Michelle Sneed, it's not family farms that are sucking up the most water. Rather, it's large finance firms like Prudential, TIAA-CREF, and Hancock Agricultural Investment Group. To cash in on surging demand for nuts among China's growing middle class, these companies are buying up California farmland and plunking down nut orchards; acres devoted to pistachios jumped nearly 50 percent between 2006 and 2011, and the almond orchard area expanded 11 percent. Nuts are some of the thirstiest perennial crops around, with a single almond requiring a gallon of water and a pistachio taking three-quarters of a gallon. So when the finance companies snatch up farms in the Central Valley, they're also grabbing groundwater—and California places no statewide limits on how landowners can exploit the water beneath their land. Even Texas, a state known for its deregulatory zeal, has stricter rules....MORE
The Great American Desert - A long-term perspective on drought history in the Great Plains
Some of the papers that we've looked at over the years:
Temperature and Precipitation Patterns Associated with the 1950s Drought in the U.S. Southwest
AMO, PDO AND SEVERE DROUGHTS IN THE CONTERMINOUS US: A SOUTHWESTERN PERSPECTIVE
Pacific and Atlantic Ocean influences on multidecadal drought frequency in the United States
See also:
"U.S. Private Weather Agencies Predict WEAK El Niño in 2014"
Trading the California Drought: Almonds and Water
Projected Price Increases For Foods Affected By the California Drought
California Drought: Why Farmers Are 'Exporting Water' to China
El Nino Won't Come Quick Enough To Break the California Drought
U.S. Drought Monitor August 14, 2012 (and a look at megadroughts)
Ocean changes may trigger US megadrought
Finally, from our 2008 post "A Black Swan in Food":
...Donald Coxe, chief strategist of Harris Investment Management and one of my favorite analysts, spoke at my recent Strategic Investment Conference. He shared a statistic that has given me pause for concern as I watch food prices shoot up all over the world.
North America has experienced great weather for the last 18 consecutive years, which, combined with other improvements in agriculture, has resulted in abundant crops. According to Don, you have to go back 800 years to find a period of such favorable weather for so long a time.
