But they're not alone: roughly half the nation lives with unhealthy concentrations of ozone or particulate pollution.
Paradise really doesn't come cheap.
Our brains evolved to work most efficiently in natural environments.
The people and ideas reshaping urban life
The financial benefit of moving for a new job has been cut nearly in half over the past few decades.
A Silicon Valley start-up has invented an energy storage device that could take an entire neighborhood off the grid.
When it comes to getting a visa approved, it helps if you work in the finance sector.
Does that urban sibling connection mean anything at all?
Salt Lake businesses are booming as they find international markets for their goods.
A new film makes the case that the city's at risk of losing the very urban vitality that attracts visitors there in the first place.
A comprehensive look at which parts of the world have suffered historically large quakes.
Cities stand at the very center of each and every one of the biggest challenges the world now faces.
"Our customers don't anticipate drinking water that's been contaminated by some yahoo who decided to pee into a reservoir."
The eastern part, anyway; in the West it will be hotter and drier, predict scientists.
Those cold snaps helped spawn an intense outbreak of pollen.
The Indian city is finding a path out of an urban trash crisis by bringing dignity to workers who once were ostracized.
There's never been a better time to be a consumer. But it's not such a happy story for the people behind the counters.
This week's Cosmos explained how plants produce clean energy, and how our inferior energy technologies produce climate change.