Mr. Elowsky was right in his letter of May 20 in that there have been many different concentrations of carbon dioxide in the earth's atmosphere over the last billion years. And, yes, carbon dioxide does greatly affect plants and animals of the earth. Some species benefit from high concentrations and some from low.
However, paleoclimatologists correlate the various climates of the last five hundred thousand years with carbon dioxide concentrations in the atmosphere. High concentrations of CO2 equals warm temperatures and low concentratigns equals cool temperatures. Each of these climate changes has resulted in either the extinction or the advance of various species. We have had mastadons and camels in Michigan in the past and now we have rabbits and deer. We Homo sapiens are part of this environment. Might climate have played a part in our ancestors' ability to migrate out of Africa and bring about the extinction ofthe Neandertal "people" of Europe? Changes have consequences.
There is an old saying "Don't mess with Mother Nature," and we are messing with her big time by the unleashing of massive amounts of carbon dioxide into our atmosphere. How will people 50, 100, or 1,000 years from now be able to handle these changes we are bringing about?
There hasn't been enough outcry about carbon dioxide levels. We have to think beyond the end of our nose and do our part to keep it from getting worse.