Even with ideal light conditions, there's still more to consider.

I lived in Louisville for many years. It's fairly green as cities go. In older parts of the city, trees had been planted between the streets and sidewalks ... definitely a long time ago, maybe 30 to 50 years? Maybe longer?

Every spring, we lost a number of those trees to thunderstorms. Enough rain, followed by strong winds, would topple multiple trees. Every single one that I saw had a root ball that was exactly the size of the opening where it had been planted, so maybe two square meters and maybe a meter or two deep. (For those keeping score at home, that's not enough root volume to support a full-sized tree.)

So we'd lose those lovely trees and on a good day, we'd lose the use of the street for a while. On a bad day, someone would lose a car or a chunk of their house.

"Just plant more trees in the middle of the city" is not the brilliant fix that many people seem to think it is.