How come all the bad ozone that shows up during pollution alerts doesn’t float up to replenish the good ozone that’s disappearing from the ozone layer? Where does the bad ozone go? If we sawed off LA and floated it down to the antarctic would we solve all our problems? Conversely, during the next ozone alert, could we break into a warehouse full of old chlorofluorocarbon-laden hairspray and clear the air? –Russ and Larry, Chicago
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Someday I’m going to call up some famous scientist with one of these brainstorms and he’s going to say, “Damn, why didn’t I think of that?” Unfortunately, it hasn’t happened yet. The problem with ozone is that it’s unstable–it breaks down in a few minutes, long before it can float much of anywhere. Ozone is created and destroyed continuously as a result of the sun acting on oxygen in the presence of pollution (in the lower atmosphere) or on oxygen alone (in the upper atmosphere). Lower-atmosphere ozone, hereinafter called local ozone, decomposes once it gets beyond the cities that spawn it and never reaches the upper atmosphere.
Now for your last question. Suppose we decided to take our chances with UV and get rid of excess local ozone instead. Could we do it by spraying the air with chlorofluorocarbons (CFCs), the leading cause of ozone depletion in the upper atmosphere? Nice try, but no. CFCs as such don’t destroy ozone; the dirty work is done by chlorine, a CFC breakdown product. CFCs don’t break down until they reach the stratosphere (unlike ozone, they’re quite durable), where ultraviolet radiation causes them to release the fatal gas.
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