Is Any Land Pristine?

" 'A lot of the urbanization globally will take place in desert regions,' says Nancy Grimm, an ecologist at Arizona State University. Lessons gleaned here could well help cities around the world.

Greater Phoenix's 3.2 million inhabitants sprawl across 2,000 square miles of what once was an oasis in the Sonoran desert. Home to the sixth-largest city in the United States, the region is expected to double its population by the middle of the century. It has been continuously inhabited since at least AD 500."