Weather balloons could take very high altitude air samples.
But you must remember that despite what the modelers assume the atmosphere is not a homogeneous mixture and sampling methods, efficiencies of detection and numbers of samples taken are drastically different 50 years hence.
“drastically different 50 years hence.”
There’s no question about that. I was just trying to figure out how they arrived at their figures for 1960s. It seems that whenever you see anything about weather balloons, they’re always being released in fairly unpopulated areas. I would think one wouldn’t want to release them near airline routes, etc. So, considering that. their figures might be extremely low. A higher figure would show a much slower than predicted rise in atmospheric chlorine, ozone, whatever!
The high altitude weather balloons sampling the 50’s and 60’s were almost all done by (or for) the DOD nuclear testing programs, and to test for enemy nuclear weapon explosions. To see what we were releasing (and how to cover it up, clean it up) and what they were releasing - to see how powerful their bombs were and how well we could detect bomb blasts.
Very, very little was openly released then (particularly then) and now? If you get data, how relevant it is (in the hands of today's propagandists?