Green roofing can drastically alter the way buildings function in cities. Installing greenspace on rooftops can prevent water runoff, insulate the building better, create a habitat for wildlife, and cool down the city if implemented in a large-scale way. Attached are several videos of this most excellent concept!
Videos
Green Roof Day: https://www.youtube.com/watch?v=2JCaBo9cuL4&t=9s
Roof Gardens: https://www.youtube.com/watch?v=gWrsdtvUzDA&t=24s