Ummm, I am no chemist, but your reasoning and the reasoning of the columnist sounds very faulty.

First, its the emission of 'free' singleton Cl in the upper atmosphere, which then acts as a catalyst...

Free Cl is, well, very rare as it is *highly* reactive with organic molecules (thats what makes it a good cleaning agent). Fluorocarbons are in a nice gasseous form to deliver Cl right up to the upper atmosphere.

Look, there is nothing unique to Cl, or ANY element or compound, that makes it necessarily "bad" for the enviornment. its How much stuff, where and when.

HCl is a deadly acid, but you can't eat or live without it...Arsenic is a needed trace element for most multicellular life. In the right doses in the right context, it too can kill-off the environment. The same thing can be said for Salt, Phosphorous and magnesium. Heck, even enough water can kill an organism...

The medievalsts used to endorse this sort of reasoning that "likes" were harmless and "opposites" of a good thing was bad. In fact it dates back to Pholgiston chemistry. I don't think you should try to employ this reasoning in the modern era...

Davin L.