...does not prove what the cultists say it proves. Let's look at Tyndall's paper. Tyndall (1861) De Saussure, Fourier, M. Pouillet, and Mr. Hopkins regard this interception of terrestrial rays as exercising the most important influence on climate. Now if, as the above experiments indicate, the chief influence be exercised by the aqueous vapour, every variation of this constituent must produce a change of climate. Similar remarks would apply to the carbonic acid diffused through the air, while an almost inappreciable admixture of any of the hydrocarbon vapours would produce great effects on the terrestrial rays and produce corresponding changes of climate. It is not, therefore, necessary to assume alterations in the density and height of the atmosphere to account for different amounts of heat being preserved to the earth at different times; a slight change in its variable constituents would suffice for this; Such changes in fact may have produced all the mutations of climate which the researches of geologists reveal. However this may be, the facts above cited remain; they constitute true causes, the extent alone of the operation remaining doubtful.Carbonic acid refers to CO2. He says it happens, but he doesn't know how much. Now let's look at this, from the site's author: I have included the full text of Tyndall's 1861 dissertation on the opacity and radiative emission of gases because it would seem that those citing Tyndall have not bothered to read his work. It is immediately apparent that Tyndall did, at no time during his research, measure any radiative absorption. Tyndall's "absorption" measurements are revealed, by his method, to actually be measurements of opacity. I refer you to the Frontispiece of the article reproduced here. Nowhere does Tyndall account for the proportion of opacity due to reflection, nor is any attempt made to simultaneously measure both opacity and emission in order to determine what proportion of opacity is due to absorption, in spite of the significant reflection of visible radiation by chlorine gas, which Tyndall actually handled. This is probably a fundamental misunderstanding on Tyndall's part because he uses the terms "opacity" and "absorbing power" interchangably throughout his work. For more information concerning why I've included Tyndall (1861) among the most misquoted and abused papers in the public domain, see Most Misquoted and Most Misunderstood Science Papers in the Public Domain..In short: It doesn't prove what the cultists claim it proves.