Will the NYT state the obvious? The Anasazi ruins are tangible evidence that climate change is an ongoing process that man does not cause, nor can man prevent.
There is a reason why the Anasazi typically built their settlements in cliffs, and it sure wasn’t convenience.
They had to climb down to get water, and they had to climb up to get to their crops. That’s hard work.
The logical inference is that it was for defense, and it might well be that each Anasazi settlement was not exactly on friendly terms with the others.