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Trina Hamilton

Pedestrians stroll along the High Line in New York, Wednesday, Sept. 17, 2014, as it winds between two buildings under construction. The last stretch of the elevated walkway opens to the public Sunday, Sept. 21. (AP Photo/Kathy Willens) (AP)

Sustainable cities need more than parks, cafes and a riverwalk

Trina Hamilton, Winifred Curran