It was 150 years ago that John Tyndall, one of history's truly great physicists, published a scientific paper with the far-from-snappy title On the Absorption and Radiation of Heat by Gases and Vapours, and on the Physical Connexion of Radiation, Absorption, and Conduction. BBC News - Tyndall's climate message, 150 years on Tyndall's climate message, 150 years on Comments (22) There's a welter of environmental anniversaries this year, notably the 50th birthday of WWF and the 40th of both Greenpeace and Friends of the Earth International. Much less trumpeted, but in its own way more significant, is one that dates back to the middle of the 19th Century, which is being marked this week by a special conference in Dublin. Not a title to excite the senses at first sight, perhaps; but nowadays, the basis for a vitally important branch of science and a particularly noxious brand of political discourse. What Tyndall had demonstrated for the first time was that gases in the atmosphere absorb heat to very different degrees; he had discovered the molecular basis of the greenhouse effect. Its existence had been surmised by earlier generations of scientists, notably Joseph Fourier, who wrote in 1824: "The temperature [of the Earth] can be augmented by the interposition of the atmosphere, because heat in the state of light finds less resistance in penetrating the air, than in re-passing into the air when converted into non-luminous heat." We're finding out that he may of been wrong because it goes against the law of thermodynamics. You have to ask how great was this man as a physicist? I'm serious, where is the math and data for people trying to defend his theory to win people over to it?