Sunday, November 27, 2011
Return of the Dust Bowl to the American West
The cover story in the November issue of AGI's EARTH magazine offers a grim prediction of the "Return of the Dust Bowl in the American West" that includes Arizona.
The article says researchers from a variety of disciplines concur that "Over the next two or three decades, the American West...will transition to a climate that may make the 1930s Dust Bowl seem mild and brief."
This summers multiple haboobs in southern Arizona are given as examples of what the future may increasingly hold for us.
The cause is a combination of natural and human causes. "Persistent drought, increasingly violent and variable weather, urban and suburban development, off-road recreational vehicles, and even the installation of large-scale solar energy arrays threaten to shroud the West in dust."
One of the biggest factors, and biggest unknowns, is the Pacific Decadal Oscillation (PDO) that moves on a cycle of 20-50 years. A favorable PDO is described as the source of the anonymously wet 20th century, on which we based a lot of our water planning.
In addition to drought-related effects, longer dry seasons lead to more wildfires. And the increase in dust brings more respiratory ails such as carrying more Valley Fever spores.
It's possible there will be a change in trajectory of one or more of the causal factors, but the article cautions that none of that seems to be happening.
at 7:26 PM