To the editor:

Having read some of the semi-popular scientific literature regarding global climate change/warming, Lee Gerhard’s statements certainly raise some questions. He talks of depending on the data in contrast to the results of computer programs. I wish he had cited some of his sources of data. For example, he says, “The greenhouse effect of carbon dioxide logarithmically declines with increasing concentration.” I’d like to go to the science library to read articles supporting this finding.

He also writes, “but carbon dioxide concentrations at present are near the lowest in geologic history.” When I read Science News, Scientific American, etc., that is not what I find there. Professor Gerhard, do you fault the scientific methodology of these scientists, including some at KU? They have examined ice cores going back 800,000 years, more or less — several ice ages and interglacial periods.

According to their findings carbon dioxide during glaciation was usually around 180 parts per million, and around 280 ppm during warm intervals, such as the present age. Other scientific observers in mountaintop locations, taking readings of CO2 in the stratosphere, report that CO2 levels are presently 385 ppm.

I hope Gerhard will write again, explaining these apparent contradictions, and give some citations to the scientific literature.