The AGW community would have you believe that the science in favor of AGW is settled. As a professional scientist, a physicist with 40 years experience in aerospace and extensive knowledge of atmospheric physics, I can tell you that, indeed, the science is settled, but not the way the AGW extremists would have you believe. Atmospheric transmission measurements taken in the 1950s demonstrate conclusively that increasing CO2 concentration in the atmosphere cannot be the cause of global warming if global warming even exists.
A basic principle of science is that correlation does not prove causation. Climate scientists are working overtime fudging temperature related data showing global warming over many decades that correlates with the industrial revolution and increasing use of carbon-based fuels. Climate scientists are boldly asserting that this correlation proves global warming is caused by increased CO2 in the atmosphere.
Real scientists would demand to know the physics of how increased CO2 in the atmosphere causes global warming. Is there any real physics behind this unsupported bold assertion? As I am about to explain, based on test data from the 1950s, there is not.
There are three points I want to make that fall in the categories of physics and atmospheric physics. First, molecules in the atmosphere absorb lightwaves over what are called spectral bands. The spectral band can be narrow, as small as a single wavelength, or broad, covering a continuum of wavelengths or frequencies. This molecular absorption causes increased vibration within the molecule exciting certain vibration modes. The physics of each molecule determine which wavelengths can be absorbed to excite internal vibrations. Spectral band absorption in the atmosphere can be quantified based on measurements over a certain distance through the atmosphere such as “90 per cent absorption in this spectral band over a distance of 300 meters at sea level through the atmosphere”.
The second point is not really atmospheric physics, but more fundamental. Objects like the earth emit a spectrum, or wavelength continuum, of radiation that is completely described by “Planck’s Law” of black body radiation, derived in the 1900 by Nobel-winning physicist Max Planck. That curve predicts the peak intensity of light from the sun in the visible spectral band, and the peak intensity of light emitted by the earth in the LWIR spectral band. Planck’s curve has been validated by experimental data for over a hundred years, and was a huge breakthrough for the physics community in the 20th Century.