As a result of your Link T i wondered what effect Airplanes have on our ozone. That then led me to a few different reports that all inferred or clearly state that there is sizable atmospheric mixing between Strato and Tropo. All be it in the tropical and sub tropical lattitudes
I also learnt that the Troposhere holds about 20% of all ozone.
So i am of the opinion that low grade volcanoes must be having an effect on our climate. Both by cooling via the aerosols and to a lesser extent indirect heating by depletion of the ozone
Now this is not dig at either of you two. it is just a suggestion that i find it difficult to believe that there has been increased volcanic activity and it is not having an effect on our climate.
