30 Fairmont Park Lane S
Lethbridge, AB
T1K 7H7
Phone: (403) 328-1804
Tuesday, November 10, 2009
The Editor
The Lethbridge Herald
P.O. Box 670
Lethbridge, AB, T1J 3Z7
Dear Editor,
Neophyte climate hobbyist Gwynne Dyer makes some extravagant claims for CO2 induced climate change in his column of November 1. One could conclude that he has been convinced that changes of CO2 in the atmosphere have been the sole driver of climate change going back millions of years. No doubt his hasty survey, circa 2007-2008, of scientists and other players dedicated to the premise of CO2 induced warming has fostered and reinforced his unquestioning belief in human induced global warming.
Unfortunately the science is not quite that easy. I remind readers that we learned in grade school that climate has changed drastically over the millennia. We were presented with ample evidence of this including the observation that our part of the earth came out of an ice age only a few thousand years ago. I recall that this was attributed to changes in the earth’s orbit around the sun. Those changes, in turn, change the amount of energy from the sun and the parts of the earth that are heated by it.
Superimposed on such changes are many more subtle effects within the atmosphere. These radiative heat transfer properties of gases within it including water vapor and trace quantities of CO2, the formation and dissipation of clouds, dust in the atmosphere, etc.
Some climate scientists have built computer models which attempt to calculate the result of all these complex interactions. The degree of warming to be expected from CO2 changes is still disputed. Many are convinced tiny changes in the earth’s energy balance from CO2 will be amplified by other effects resulting in a substantial warming. Others are doubtful.
For example, Richard Lindzen, a climate scientist of considerable repute has been skeptical of the more extreme warming predictions. He has been evaluating satellite based measurements of radiation from the earth and is coming to the conclusion that the effect of CO2 on warming are much less than commonly predicted. Of course his work is complex and not as easy to follow, or as satisfying to some, as sensational and simplistic assertions that rising CO2 levels spell doom for the planet.
For serious readers, who are open to learning more about climate change I provide a link to Dr. Lindzen’s website. http://www-eaps.mit.edu/faculty/lindzen.htm
Yours truly,
Duane Pendergast