Like I always think that people don’t get one thing about trees in a city. There purpose is is not about co2. The co2 reduction of city trees is neglectable. The reason you need them in a city is temperature regulation, shade, air quality, mood, the local eco system and maybe solidifying unsealed ground. Putting these tanks in a city is laughably inefficient w.r.t. co2 conversion if you compare this to any effort to do this in instustrial capacity ( which is is also still laughably inefficient)
I think there is a difference between air quality (pollution) and co2 levels.