We could not have sustainable ecosystem with humans included. But we could leave some space for greens and vegetation. What I meant is - if you want a tree at

We could not have sustainable ecosystem with humans included. But we could leave some space for greens and vegetation. What I meant is - if you want a tree at floor X, you also need to have soil, worms, grass, bushes, spiders, beetles around it. Of course this is the icky stuff that people in the high rises don't want to deal with too much. But it is definitely doable with some nice mirror play, rain collectors, windbreakers (for the higher floors) and leaving some floors empty to have high rise gardens. But you cannot just lift a tree with roots - you must put up soil and plant stuff and wait. It could be nice places for socializing. So we turn the trees from gimmick into something that creates value.