Mike Amos, I think I saw that very same television report, and it was full of so impressive images!
No, I understand exactly what you're saying, and you're not "dampening" (does this word exist in English?) the topic at all. A specialist seminar at the beginning of this year, which I assumed would put this topic on a holy throne, dealt with it in a very critical and reflective manner.
I myself also doubt that greening facades is the key to a better urban climate and consider it more of a niche solution that is only appropriate in certain places.
I live in Frankfurt and have observed the efforts being made there to remove sealing materials from large squares and even streets and replace them with green spaces and tree plantings. Even then, I often thought beforehand, βWhat's this going to be like?β but it actually got better. All in all, I think that a lot of trial and error is going on at the moment β which is better than not trying anything at all. Even if something goes wrong, you have gained knowledge and experience.
I am very pleased about all these contributions and comments β especially since this topic started with an amateurish attempt to model and visualise a green wall system in SketchUp 