Milan has the ambitious plan to plant 3 million new trees by 2030, a move experts say that could offer relief from the city’s muggy, sometimes tropical weather. Some projects have already contributed to environmental improvements: architect Stefano Boeri’s striking Vertical Forest residential towers, completed in 2014, aims to improve air quality so the quality of life for Milan residents. The project to make Milan greener includes another plan meant to transform a disused freight railway network into a series of seven parks, with new trees planted every year. It also includes planting greenery on flat rooftops and in many school courtyards. By 2030, Milan hopes to become a model for the big cities of the future.