Don't confuse global warming with atmospheric ozone depletion.

It's hard to talk to people without someone bringing up environmental pollution, global warming and destruction of the earth's protective ozone layer.

Global warming has little or nothing to do with atmospheric ozone depletion. But since both ideas were heavily suggested during the same decade (1970s-1980s), most people think that global warming is caused by ozone depletion. It isn't. Here's why:

Ozone depletion is the reported thinning of the layer of stratospheric ozone that protects the earth from hard ultraviolet radiation which comes from the sun. The risk there has to do with killing sensitive life forms and causing high rates of skin cancer among humans, but it doesn't cause the earth to get warmer.

Global warming is said to be caused by the release of heavy gases and vapors into the atmosphere by industrialization and the growing number of internal-combustion engines. These heavy gases retain more heat because of their dense structure, and if they don't break down in the atmosphere easily, they can cause some warming effect.

So what tie is there between global warming and destruction of earth's ozone layer? It is said that both problems are the result of pollution and the creation (and release) of synthetic gases - such as what most people have come to call "freon." Freon is just a DuPont trade name for any of its full line of chlorinated refrigerants. There are many other trade names for the same substances manufactured by other companies, but at least here in North America, the freon name has stuck.

I did a lot of research on this subject back in the late 1980s when I accepted a commission from the Air Conditioning Contractors of America (ACCA) to look into the effect that the release of refrigerants was having on our environment and how that would impact our industry. I attended several important environmental conferences and was given access to many key environmentalists from DuPont, the EPA, and even NASA. I wrote a series of articles on the subject that was groundbreaking for our industry and which won me the business press' most prestigious journalism award in 1990.

The theory of global warming certainly has its proponents. Every time we read a piece on glacier melting or about an iceberg floating in the mid Atlantic, the news media is quick to proclaim this as proof of global warming. Yet other scientists claim that the earth is headed toward a period of global cooling. Who is right?

Well, I'm not going to pretend to be the final authoritative source on this subject. However, I doubt that the earth is warming. Why? Because any so-called proof isn't supported by global weather statistics. A change in the average temperature that is just a couple-tenths of a degree from the norm isn't enough data to come to such a conclusion. And if you compare today's air-pollution levels to the smoke and pollution from factories and the deforestation experienced at the turn of the 1900s, I think we're better off today.

However, what effect does the release of refrigerants have on global warming? The amount of refrigerants that has been released into the air over the past 60 years (since "freon" was invented around 1940) is minutely small when compared to its use in cooling by individuals worldwide. All the "global warming" gases released by refrigerating and air-conditioning systems worldwide doesn't amount to the global warming gas (carbon dioxide) which a globe full of people and animals exhale in a single day. Yet, heavy refrigerating gases can add to the problem.

The history of the earth shows at least one past period of major global warming that wasn't caused by man. The huge petroleum reserves found in northern Alaska and in Siberia prove that the earth's climate was once much warmer than it is today - and life not only survived, it thrived.

I'm sorry if my pooh-poohing of the global-warming theory may upset you. I may be wrong. However, it's a fact that the release of our industry's refrigerants hasn't been a significant factor in such warming to date. On the other hand, I strongly believe that refrigerant releases are causing depletion of earth's protective ozone layer, and that will be the subject of a future article.