Permaculture as a Solution?

There's an outfit in the Midwest which is pushing "permaculture"--the idea if we could convert from annual crops to perennials we'd save on expenses for fuel, etc. and be more friendly to the environment.   I mention this because this Extension post on cotton includes this:

"A defining characteristic of cotton growth and development is that it is a perennial plant. Being a perennial plant means that it flowers and sets fruit over a long period of time. In its native habitat, or with adequate warmth, cotton would not die in the fall. Perennial plants also flower and produce seed as a secondary mechanism, as opposed to vegetative growth. Because cotton lint is produced from the seed coat, it is the essential challenge of cotton production to overcome the perennial nature of the plant. Nearly everything we do to manage a cotton crop is in response to its perennial nature in an attempt to produce seed and lint in an annual row crop environment."

 I've expressed my doubts about permaculture before, but with global warming the frost line will move north and we won't have to plant cotton every year. (In the Rio Grande valley they speak of "stub cotton", cotton which is growing from previous year plantings.)