Viable careers in city planning/related fields?

[Pinion]

As the constant rain continues to beat down my morale I am thinking more and more about getting out of blue collar work and using my brain to make money again. Obviously I have an interest in city planning and other similar fields that posters here are probably doing right now. Are there any suggestions on what to study or what fields to go into for an in-demand, intellectually stimulating career?

I'm willing to go back to school for four years if I have to.