Climate change and global warming — Ronald Harriman in his Dec. 29 guest opinion to the Statesman expressed skepticism about the role human activity has in the current trends in global warming. He describes the rather dramatic fluctuations in temperature that our earth has experienced over the past eons, owing to cyclic changes in the direction of the earth’s axis of rotation.
Harriman suggests that human activity is a small perturbation on the overall course of our climate produced by normal factors that occur over thousands of years. Unfortunately, our civilization will not readily accommodate a sea rise of 600m or a temperature rise of 20 degrees. Even the rather small changes attributed to human activity that have occurred during the past 50 years have had rather significant effects.
Human activity has contributed approximately a 22 percent increase on the amount of carbon dioxide during the past 50 years (310 PPM to 400PPM) that resulted in a global temperature increase of about 1 degree Fahrenheit — not much but polar ice and glaciers have receded; the amount of water vapor in the atmosphere has increased; and there has been a noticeable rise in sea level. This is data, not hyperbole. Humankind take notice.
David L. Ederer, Meridian