The Big Squeeze: Can Cities Save The Earth? : Krulwich Wonders... : NPR

So, you think that "low rise" is eco-friendly - it is actually eco-selfish since land is a finite resource.  Click title for link to an illuminating article with some real scary pictures for the "Yes" crowd.  From the article:

Because cities, even the ugliest ones, have an obvious efficiency. After all, if all 7 billion of us had to live side-by-side in two story ranch houses, or yurts — no towers allowed — we'd overrun the planet; we'd strangle the forests, the meadows, the plains. So until we learn to have fewer babies, cities may be our salvation, no?

Also take a look at the Per Square Mile blog, very minimalist but has some enlightening information.