“A Permanent Drought Seen for Southwest” is our site of the day

A study published in the journal “Science” is the subject of the lead story in today’s Los Angeles Times. The Times article, “A Permanent Drought Seen for Southwest”, gives many of the details of this study by Richard Seager, a research scientist at the Lamont-Doherty Earth Observatory at Columbia University, and a distinguished group of experts from different countries.

The Times article begins:

The driest periods of the last century — the Dust Bowl of the 1930s and the droughts of the 1950s — may become the norm in the Southwest United States within decades because of global warming, according to a study released Thursday.

The research suggests that the transformation may already be underway. Much of the region has been in a severe drought since 2000, which the study's analysis of computer climate models shows as the beginning of a long dry period.

The complete study, “Model Projections of an Imminent Transition to a More Arid Climate in Southwestern North America” was published yesterday in the online version of “Science” and can be accessed for $10 unless you subscribe to this journal.

Some of Dr. Seager’s research in this area can be accessed through his home page at Columbia University. The first link on his page describes where his research has taken him:

• Southwestern North America and other subtropical regions are going to become increasingly arid as a consequence of rising greenhouse gases.
• The transition to a drier climate should already be underway and will become well established in the coming years to decades, akin to permanent drought conditions.
• This is a robust result in climate model projections that has its source in well represented changes in the atmospheric hydrological cycle related to both rising humidity in a warmer atmosphere and poleward shifts of atmospheric circulation features.

The LA Times article is long and detailed and should suffice for all but the most avid of readers on this subject. It is another wake up call as Southern California, jammed with more and more people and spreading to inland regions, struggles with this year’s record drought. While precipitation will change from year to year, the long term pattern is ominous.