92nd American Meteorological Society Annual Meeting (January 22-26, 2012)

Monday, 23 January 2012
Tyndall Gases
Hall E (New Orleans Convention Center )
John Nielsen-Gammon, Texas A&M Univ., College Station, TX

Climate change is quite complicated for the layman to understand. The matter is made worse by the use of a term, the "greenhouse effect", that refers to a physical system quite unlike the climate system. Communication is not well served by the use of a term that means something different from what it seems to mean.

I propose that the term "greenhouse gases" be avoided entirely, since such gases are either not found in a greenhouse in special abundance or do not serve to warm the greenhouse to an appreciable extent. Instead, with respect to the scientist, John Tyndall, who first demonstrated that many trace atmospheric gases have powerful infrared absorption properties and thus may play an important role in Earth's climate, I propose that gases with strong infrared absorptive/emissive properties be dubbed "Tyndall gases".

With Tyndall gases thus identified in a manner that does not mislead as to their role in the climate system, the primary effect of such gases on the Earth's climate system may naturally be dubbed the "Tyndall gas effect". This is distinct from what is called the "Tyndall effect", the wavelength-dependent scattering of light by suspended particles whose size is comparable to the wavelength of light. The effect of Tyndall gases is to intercept outgoing longwave radiation from the Earth's surface and emit it at a higher, colder altitude, thereby raising the surface temperature needed to achieve energy balance. The limited extent to which this process resembles energy exchange in a greenhouse becomes irrelevant.

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