This is an interesting question, since we cannot know precisely what cause the nuclear destruction in "If I Forget Thee, O Earth" by Arthur C. Clarke. This story is set in some future time in a lunar colony, probably the moon. A ten-year-old boy, Marvin, has never been outside the colony, but today his father takes him in a lunar scout car to the other side of the planet so he can show his son the earth--or what is left of it.
What Marvin sees takes his breath away, as he recognizes water and continents he had studied but never seen.
Then Marvin, his eyes no longer blinded by the glare, saw that the portion of the disk that should have been in darkness was gleaming faintly with an evil phosphorescence: and he remembered. He was looking upon the funeral pyre of a world—upon the radioactive aftermath of Armageddon. Across a quarter of a million miles of space, the glow of dying atoms was still visible, a perennial reminder of the ruinous past. It would be centuries yet before that...
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