HIGHLANDS RANCH, CO—North American cities lag their counterparts in Europe and Asia when it comes to sustainability, Arcadis said Monday. The inaugural Sustainable Cities Index from the locally based design and consultancy firm found that while New York City, Los Angeles and Chicago generate strong financial returns, they're hampered by poor transportation infrastructure, lack of green spaces and diminishing affordable housing.

The index, conducted by the UK-based Centre for Economics and Business Research, used the “triple bottom line” of people, planet and profit to develop a ranking of 50 of the world's leading cities based on 20 key indicators. Among the North American cities covered in the study, none was found sustainable enough to crack the global top 10.

At number 15, Boston ranks as the most sustainable US city covered in the study. The others ranked as follows: Chicago in 19th place; New York City, #20; Houston, #21; Philadelphia, #22; Washington, DC, #25; San Francisco, #27, Los Angeles, #28; and Dallas, #29.

The most sustainable North American city ranked by Arcadis was Toronto, which came in at #12 on the global list. Frankfurt, London and Copenhagen comprised the top three worldwide.

All of the US cities ranked in the bottom half of the list when it came to carbon emissions, a trait they shared with cities in the Middle East. Similarly, New York City, Hong Kong and Seoul all are marked by a trade-off between strong education and poor work-life balance.

Arcadis' study found that city leaders are faced with a complex balancing act of generating strong financial returns and maintaining an attractive place for people to live and work while limiting damage to the environment. “To truly understand how sustainable a city is, we must understand how well it balances the triple bottom line of people, planet and profit,” says John Batten, global cities director with Arcadis. “Only then can city leaders determine their priorities and develop a roadmap to urban sustainability, for the good of this generation and the next.”