[Admin: Originally posted by Trigger Hippie, but I though I deserved a thread of its own] That's not the first time you've said something like this. Your premise that scientists would recklessly endanger the whole planet with geoengineering programs because they disregarded similar world ending scenarios during the H-Bomb tests, falls short of the mark. In 1942 the decision was made to research a fission bomb. However, Edward Teller continued attempts to gain support for creating a much more powerful thermonuclear bomb (fusion bomb). It was during those early years, when fusion was not well understood, before even the first controlled fission reaction, that Teller first speculated about how a fission bomb might ignite the atmosphere with a self-sustaining fusion reaction of Nitrogen nuclei. (Teller developed a track record for overstating the likelihood of fusion reactions. Bethe, a key figure in the bomb's development, recounted how the H-Bomb could have been produced much sooner were it not for Teller miscalculating the likelihood of thermonuclear reactions.) Anyway back to 1942. Upon hearing the prospect of an uncontrolled atmospheric reaction, Oppenheimer set Hans Bethe to look into the matter. Bethe, using early IBM digital computers to achieve his results, calculated that a fission reaction could not induce a thermonuclear reaction in the open atmosphere. Research resumed and the first A-Bomb was constructed. During the Trinity test, Enrico Fermi recalled Teller's idea of igniting the atmosphere. In an attempt to relieve some tension, he started taking bets on whether the test would destroy the world, or merely glass the State of New Mexico. Development of a fusion bomb began after the war. Soon the notion of igniting the atmosphere surfaced once again. Only this time it was speculated that a thermonuclear reaction could trigger the fusion of Nitrogen nuclei in the atmosphere. In 1946, Teller's own Calculations showed that the bomb was not large enough trigger a cascade, and even if it were, other physical phenomenon would disperse the energy required to sustain the reaction. He concluded the prospect was so improbable that it was considered impossible. Oppenheimer agreed. This meme that mad scientists will risk the destruction the world for the sake of their precious experiments persists to this day. A Scientific American article caused a big flap when it speculated the Relativistic Heavy Ion Collider might produce a doomsday scenario. This was seen yet again with The Large Hadron Collider. Scientists were not careless when they evaluated the possibility of global destruction during the first nuclear bomb tests nor are they careless when evaluating geoengineering experiments today. Some are advocating for more research in the subject so that if, at some time in the future, should it be the only card left to play, we could engage in a responsible geoengineering program that would have the highest probability of success with the least damage. As a side note: The author you quoted made some fundamental errors. First of all, The most common element in the world is iron. Next, Teller considered the possibility of self sustaining reaction of Nitrogen, not Hydrogen. Scientists knew that even a 20% increase in yield could not ignite the atmosphere. Finally, the author tries to support his premise with a rumour!