European cities, led by Frankfurt and London, account for seven of the top 10 most sustainable cities while the other three are the well-heeled Asian tigers of Seoul, Singapore and Hong Kong, according to a new ranking of 50 major metro areas.

The rankings are hardly a surprise to anyone, including me, who’s spent time recently in the fast-growing metropolises of Jakarta, the world’s most congested city, or New Delhi, its smoggiest. I spent hours last week sitting in Jakarta’s traffic and had a difficult time breathing the December air of India’s capital. So the latest rankings, released this week, are perhaps a cautionary tale of what it takes to make a city