As part of background research for a blog entry I'm working on, I went looking for the name of the Manhattan Project scientist who was tasked with calculating whether an atomic detonation could ignite the Earth's atmosphere and burn everyone on the planet to cinders. His name was Hans Bethe and he apparently concluded the bomb would not ignite the atmosphere. But according to the Wikipedia article on the Manhattan Project, Edward Teller co-authored a paper that also examined this question.
That paper, Ignition of the Atmosphere with Nuclear Bombs, was declassified in the 1970s and it is available as a PDF for your perusal here. I recommend reading the Abstract on Page 3 and the three concluding paragraphs on Page 18. The final paragraph, which I hereby nominate as a monumental
understatement, reads as follows:
"One may conclude that the arguments of this paper make it unreasonable to expect that the N + N reaction could propagate. An unlimited propagation is even less likely. However, the complexity of the argument and the absence of satisfactory experimental foundations makes further work on the subject highly desirable."
Apparently, the "satisfactory experimental foundations" were achieved at Trinity site. Had that gone wrong, it would have brought an entirely new meaning to the term "test coverage."
[This just gets worse: As my friend Monty points out, the paper is dated August 1946. The Trinity detonation occurred a year earlier, in July 1945.]