Todd Whitcombe is quite correct when he says the science of climate is complex. He's also correct in saying the infrared absorptive nature of CO2 is not logarithmic. Yet the greenhouse effect of CO2 on the earth's atmosphere most certainly is. As Dr. Whitcombe said, only narrow bands of infrared radiation are absorbed by CO2, and they are not present in the infrared radiated from the sun. Only when the heat has been re-radiated from the earth's surface are the absorbable bands available for CO2 to absorb, and then only in small amounts with the result that adding more CO2 to the atmosphere will have almost no warming effect because there's almost nothing for it to absorb. This is well established in science, acknowledged by the IPCC and is the reason they use feedbacks in their models to get the warming projection that they can't get with CO2 alone (which explains why their projections are so spectacularly wrong.)
Dr. Whitcombe neglected to mention that the atmosphere of Mars is also in the neighbourhood of 96% CO2 and on a hot summer day at the equator, the temperature might reach as high as -40. Clearly there's more involved in planetary temperature than CO2. There are extensive studies that indicate that fluctuations in solar activity are the main drivers of climate change on the earth and that CO2 plays a minor role. The multi-billion dollar global warming industry ignores this science and one can only assume it's because it could bring about an end to the global warming gravy train.
Climate change is something we should be concerned about, but not the warming. We know that humanity made some of its greatest advances during past warming events (warmer than at present) and that past coolings were hard on us. Some scientists who study the sun are predicting that we are on the cusp of a major cooling. If true that could mean the failure of northern grain production and world-wide hunger. That is a real threat that needs to be addressed.
Art Betke
Prince George
