It is all voodoo science to scare people into doing what they "feel" is the right thing to do.

Granted resource management is very important and pollution management is a good thing, but people jumped in the 70's and 80's because of places like L.A. and their smog issue. Of course nobody thinks that maybe the concentration of people and the fact that it is in a valley may just have had something to do with their smog issues.