Column: Climate change science and politics
I very recently read another letter to the Daily Courier editor about climate change that questions the importance of CO2 in our atmosphere. These letters correctly point out that CO2 is a very, very, very small component of our earth's atmosphere. So small, in fact, that if it didn't play such an important role in warming our planet it surely would not be missed.
As a lifelong atmospheric scientist I understand how strange - even unbelievable - the behavior of this remarkable atmospheric gas can seem. CO2 is just one of several gases in our atmosphere that are known as greenhouse gases. These gases earned this name because they act in our earth's atmosphere almost exactly like an ordinary greenhouse acts.
Here's how they do it. Atmospheric greenhouse gases like CO2 act to permit our sun's short-wavelength radiation to pass through our atmosphere (like sunlight passes freely through the glass roof of a greenhouse) - the sun's radiant energy then serves to warm the surface of our planet. At the same time, these greenhouse gases act to trap the long-wavelength (infrared) radiation that wells up from the warmed earth's surface within the atmosphere itself (like the heat that wells up from a greenhouse floor is trapped in the greenhouse). This radiant energy from the earth's surface then serves to warm the lower layers of our atmosphere! This process in our earth's atmosphere is known by atmospheric scientists as our atmosphere's Greenhouse Effect.
We are very fortunate these greenhouse gases behave the way they do - because their behavior causes the average surface temperatures of our planet to be about 50 degrees C warmer than it would be otherwise. Which makes our planet warm enough for us to live on.
Someone could argue that something other than our atmosphere is responsible for the livable temperatures of our planet. Before they do, I hope they would consider the fact that while our Earth and our moon receive about the same amount of radiant energy (per square meter) from our sun, the average surface temperature of the moon is about minus 36 degrees C. This observation shows how fortunate we are that Earth has an atmosphere - and that it contains greenhouse gases like CO2 (too much CO2 in our atmosphere is bad for our planet and us. But this is another story - which I hope someone who is familiar with its many science complexities will tell it here).
Finally, I'd like to express my hope that future discussions of our planet's changing climate in this newspaper will avoid mixing scientific and political aspects of this incredibly complex and important issue in their remarks.
W. Dale Meyer, Ph.D., a retired meteorologist, has been a Prescott resident for 16 years.