Liquid Trees

Also really really hard to keep trees alive on the sides of buildings where these units could conceivably be used. Modular trees plus trees where we can fit them.

But the shade of a tree is far superior and reduces the overall temperature around them if many are planted, so overall much better.

Also certain trees dont need deep roots and can grow without neccessairliy damaging the pavement.

You can take trees and replant them in the city, you don't have to grow it there. There are tree farms.