Upper Ozone Depletion Declining
Silas writes "This SF Chronicle article (and many others) reports that destruction of the upper part of Earth's ozone layer has slowed because of the international effort more than a decade ago to ban ozone-damaging aerosols. More about the study and techniques used is here. We're still a long way away from recovery, but it's a nice example of humans taking an active role in reversing some of the damage we've done."
Ozone created from lightning is different from the ozone in the ozone layer. How? Well, it's not in the ozone layer (nor would it really make its way there). Having ozone at ground level is a problem--particularly for asthma sufferers and the like--so ozone from lightning (or arc welding, for that matter) isn't going to help.
Of course, if one were to arc weld while riding an SR-71...
This side up.