Is Arizona sustainable?

Is Arizona sustainable? That question was raised by Andrew Revkin of the NY Times dotearth blog last week, in a side story to President Obama's commencement address at ASU. [right, Phoenix. Credit, phoenix.gov]

Revkin interviewed Charles Redman, director of the ASU sustainability program. Revkin questioned whether Arizona is sustainable, given the record of megadroughts and the state's rapid growth. I was particularly taken with Redman's answer, part of which follows:

"Arizona, to many, seems eminently unsustainable, but that is an overly simplistic (linear) view… I am often asked how there can be a city in the desert, to which I reply that is exactly where virtually all of the original cities in the world were established! The interesting precedent is that Phoenix was home to what may have been the second largest “city” in prehistoric North America (the largest I think was near East St. Louis) and the largest irrigation system north of the Andes. The conditions were just as harsh then as now. The key ingredient is that people can only be successful in this type of environment if they aggregate into larger groups and organize themselves to reduce risk and maximize control and output. In a strange way Arizona has some of the most advanced and effective water management systems largely because it is obvious that if we didn’t this place would not work at all."