There's a 75-ft. tree coming to a neighborhood near me. Actually it's a 75-ft cell-phone tower that will be disguised as pine tree. Chances are, there's one near you too.

Conventional wisdom seems to be that sprawl is bad for the planet and density is good. Does that automatically mean living in a city is better for the environment than living in a suburban or rural area? Not necessarily. How environmentally sound your lifestyle is depends less on where you live than how you live.

'Urbs

Manhattan, in many ways, is green. Most people use mass transit or walk, rather than drive. Most also live in apartments, which can be heated and cooled more efficiently than houses. Virtually no one has lawns, so there's little need for fertilizers and pesticides. "By the most significant measures, New York is the greenest community in the United States, and one of the greenest cities in the world," David Owen wrote in the New Yorker, in a story extolling the enviro virtues of living in New York City, specifically in Manhattan. "The true challenge," the article said, "is how to make other settled places more like Manhattan." Because what's true about Manhattan is not necessarily true about urban areas in general.

If you're debating between living a life in the city or the suburbs, consider this new research from the American Geophysical Union: Scientists reported their findings