As I remember it from Richard Rhodes' superb, Pulitzer-winning _The Making of the Atomic Bomb_ [1] (highly recommended for anyone interested in science), it was

As I remember it from Richard Rhodes' superb, Pulitzer-winning _The Making of the Atomic Bomb_ [1] (highly recommended for anyone interested in science), it was Edward Teller who had the sudden fear that a fission bomb might result in a fusion chain reaction that would ignite the atmosphere and boil the oceans (page 418). Hans Bethe did the calculations and determined it was not possible. However, the notion was disturbing enough that a formal report was requested. I believe this was later, in 1945 or 1946, during the development of the hydrogen bomb, but I'm not sure. The report [2], co-authored by Teller, is dated 1946. It was declassified in 1973. On the night of the Trinity test, apparently with the notion of calming people down, Fermi (to the annoyance of Maj. General Leslie Groves) humorously started taking bets on whether the test would ignite the atmosphere or merely destroy the state of Mexico (page 664). [1] http://www.amazon.com/Making-Atomic-Bomb-Richard-Rhodes/dp/0684813785 http://www.amazon.com/Making-Atomic-Bomb-Richard-Rhodes/dp/0... [2] http://www.fas.org/sgp/othergov/doe/lanl/docs1/00329010.pdf http://www.fas.org/sgp/othergov/doe/lanl/docs1/00329010.pdf