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."

Comments

OR....

[Picass0]

Could it just be that with our very limited (~40 years worth) sample of scientific data that we just do not have a very good understanding of how the cycles of the Ozone Layer work? Perhaps ozone holes occur and disappear naturally, and we are only beginning to learn this. Ozone is created every time lighting strikes the earth (about 100 time every second) so ozone is not something that goes away forever.

Re:OR....

[drlock]

I have the same question.
According to this article, "Since ozone is created and destroyed by solar UV radiation, there is some correlation of ozone concentration with 11-year sunspot cycles." (article also give a number of other natural causes of ozone layer change). The SF Chronicle said, "Between 1997 and 2000, the average growth rate of the ozone hole has slowed by approximately 7 percent per decade" That was the exact period of a spike in sunspot activity.
So how can we prove that it was the meager efforts of us humans that made the change, and not just a natural cycle?

Different ozone

[hcetSJ]

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...