This forum is about wrong numbers in science, politics and the media. It respects good science and good English.
Perhaps it could have been done 70 years ago:
We could call it an extra feature. When the attacks start, we let the balloons fly higher.
An alternative and much more predictable solution would be to build a series of wind generation devices on towers. Lets assume windmills with 300ft dia blades , to make the towers at least 600ft tall.
50ft below the blade's lowest point build a roof and below the roof include a climatic system - rain and stuff, that mimics the world outside.
The roof proved much better air flow control for the turbine blades, can be painted white to increase albedo but still allow light in and could be used to control the ground level weather for important events.
Gosh, I can think of so many benefits I am surprised no one has done this already.
A 600 ft tower is gonna be expensive.
We could build the house into it though.
I had this 'vision' of a city-wide infrastructure rather then an individual property.
Indeed the way things are headed in many countries creeping authoritarianism seems to be the future. A life without rights but not without responsibilities. Employees of Governments (all levels) with legal powers available after cursory checks on their probity.
Several local authorities in Sydney, Australia, have even banned helium balloons, or in some cases any balloons. Presumably the voters voted for this attitude. Makes me wonder what IS being added to the water ...
What next - an annually renewable licence to breathe? Remote control cut off if you forget to renew?
My favorite book "Moon is a Harsh Mistress" - Quarterly air charges for all recipients, although you could create O2 excess by growing abundant plants. Course those silly plants require CO2 to grow. Not once in the stories did they ever discuss where the CO2 came from for moon plant growth. Burning stuff wouldn't be a good idea. In the book they searched for Water in the depths of the moon. Perhaps they also searched for Dry Ice?