Three of England's cities have been ranked ahead of New York, Tokyo and Rome in a list of the world's most sustainable cities.
Research by Arcadis into the 50 most sustainable urban areas named London in second place, Manchester in 14th and Birmingham in 18th.
The Sustainable Cities Index ranked metropolitan areas on how well they met social, environmental and economic demands.
Birmingham was said to have benefitted from a rise in local young professionals and anticipated connectivity gains associated with HS2.
Frankfurt was named the world's most sustainable city, being praised by judges for its low levels of air pollution and waste management.
John Batten, global cities director at Arcadis, said: 'City leaders need to find ways to balance the demands of generating strong financial returns, being an attractive place for people to live and work in, whilst also limiting their damage to the environment.
'To truly understand how sustainable a city is, we must understand how it ranks in People, Planet and Profit. Only then can city leaders act to assess their priorities, and the pathway to urban sustainability - for the good of all.'