On Oct. 16, in your paper, FP Jordan stated that “Only .04 of one percent of the atmosphere is CO2. How can any reasonable person argue that CO2 is the primary driver of climate change.”
The .04 per cent number is correct; the CO2 levels have risen from 250 ppm pre-industrial to 400 ppm today, with ppm being “parts per million.” But, let’s examine his ‘reasonable person’ conclusion.
Small concentrations of chemicals can cause big impacts.
Sarin gas for example is lethal in parts per million. How?
CFCs, which were just invented in the 1920s as a refrigerant, caused a giant ozone hole to appear over the Antarctic. This destruction occurred based on miniscule CFC chemical levels, on a percentage basis.
Under a stream of ultraviolet radiation, a chlorine molecule (CL) would break off from the CFC chain, attaching to an ozone (O3) molecule to produce CLO and O2. The CLO then quickly breaks down again to chlorine and oxygen. As this cycle repeats thousands of times, a single CL molecule can destroy many ozone molecules.
This science is known. After a rapid growth in the Antarctic ozone hole between 1980 and 1995, a ban on CFCs resulted in a stabilization and small reduction in the size of the hole.
CO2 operates in much the same way. Visible light from the sun, at a wavelength of under 4,000 nanometers, passes directly through a CO2 molecule on its way to earth. Heat then radiates back to space as infrared radiation, at wavelengths well over 4,000 nanometers, exciting the CO2 molecules, which capture and radiate the heat, in endless cycles from a single molecule. A significant portion of this recycled heat goes back to earth rather than escape to space. The science of this activity has been known since the 1850s.
How can .04 per cent of the atmosphere have a big impact?
Mr. Jordan could have added to his argument by stating that molecules are physically separated from each other by large distances on an atomic scale, thus harder yet to ‘hit’ with radiation.
An analogy might be this:
Shoot a bullet through one billion layers of molecular thickness. What are the odds that this bullet will hit an object that occupies one billionth of the space in each layer? In fact, pretty good.
It’s not simple to understand global warming, but that doesn’t mean it isn’t happening.
The world is complex; that’s why we rely on scientists. Anybody out there who can explain how trillions of bits of movie downloads move through wires or space?
Dave G. Smith
Coldstream
