LETTERS: OZONE, GLOBAL WARMING

To the editor:

The letter from Ray Umbdenstock (Jan. 25) criticizing the EPA demands a response.

The refrigerant known as Freon is a chlorofluorocarbon. There is overwhelming evidence indicating that CFCs rise in the atmosphere and destroy ozone molecules. This is the cause of the so-called hole in the ozone which increases the penetration of ultraviolet light to the earth's surface. This probably increases the frequency of skin cancers among humans and may well be responsible for increased disease, as well as the destruction of simple plants at the base of the food chain of many ecosystems.

Mr. Umbdenstock is sadly confused between this ozone hole problem and global warming, a different, and largely unconnected problem. Global warming is thought to be caused by the increased release into our atmosphere of a number of gases, predominantly oxides of nitrogen, sulfur and carbon, much of which is the product of our burning fossil fuels. CFCs are involved in global warming only because they have the same heat-trapping ability as the oxides.

Should global warming occur at the rate current data and computer models suggest, producing a temperature increase within 200 years equivalent to that which has occurred since the depths of the last Ice Age, lowlands will be flooded, and the agricultural, forestry and marine systems of the planet, the resource base upon which human life depends, will be disrupted or destroyed. This, surely, is no trivial consequence.

Like many uninformed critics, Mr. Umbdenstock seeks proof that these problems are real. Unfortunately, the process of science is incapable of providing such certainty. First, we can never be absolutely certain that relationships studied are real because the best we have available to us are our perceptions (which may be flawed), and our judgment regarding those perceptions. Second, when we are conducting tests of hypotheses and obtain results that are consistent with those hypotheses, we must recognize that the results we obtain could be caused by something other than the cause we hypothesized. Third, we always recognize that the results we obtain may not be obtained in a different place and time. As a result of these limitations, a thoughtful scientist can only summarize the available test results, and state that 'the preponderance of the evidence' argues for a conclusion. And so it is with both ozone hole and global warming. The number of studies implicating CFCs in expanding the ozone hole, and greenhouse gases in promoting global warming is such that reputable scientists agree on the most probable causes for both problems.

These are as close to proven facts as science can get us -- but limited certainty such as this has taken us to the moon.

Umbdenstock's assertion that the air and water are clean so we no longer need an EPA denies the evidence of continued pollution and disregards the problem that without EPA regulations and enforcement, many industries would simply revert to their polluting ways of the 1950s and 1960s.

Despite evidence, we can pretend there is no problem. Alternatively, we can take the prudent, though possibly more costly, approach, and try to minimize through regulations and enforcement the damage we are doing to a planet that future generations will have to inhabit.

Arguing for immigration control is a racist or selfish red herring. The only way that limiting immigration to the U.S. could reduce global environmental problems would be if we controlled entry only from undeveloped nations where per capita environmental damage is less than here. Per capita damage in 'developed' nations is similar enough to that of Americans that limiting migration from such nations to the U.S. would have minimal global impact.

While solutions to these problems may be costly, there is no evidence that the middle class is being bankrupted. When someone argues that they have a simple solution to a complex problem, we should suspect more the presence of a simple mind.

ALAN JOURNET

Cape Girardeau