How were the Manhattan Project scientists able to predict the possibility of the atmosphere igniting after using an atomic bomb, and how did they come to the conclusion that the atmosphere wouldn’t ignite?

Question

Did the non-zero risk of the atmosphere igniting increase as nuclear weapon yields got larger and larger?

Obviously a result of watching Oppenheimer.

In: 789

Answer 1

With the data available for the calculations, the risk was 0%.
However, there was a chance the data used was not 100% correct and if certain values woud deviate more than x% from what was assumed, the potential results would be concerning.

The percentage is about the deviation required, not about the risk calculated.

The media explained it wrong and the exciting headlines remained in the peoples memory.