Would an SSBN carrying an extreme load of 100-megaton warheads qualify as a planet killer?
Short answerIt could make Earth uninhabitable for civilization without literally destroying the planet, although the panel disputes the precise physical effects.
NotesThe hypothetical gives an SSBN unlimited-range missiles and an enormous number of 100-megaton warheads, then asks whether that makes it a planet killer. The panel broadly agrees that such an arsenal would be catastrophic for human civilization and much of the biosphere, but it disagrees over how much physical damage the Earth itself would sustain. Participants also contrast distributing detonations around the world with concentrating them in one location and mention the added consequences of ground bursts. The exchange is best understood as a speculative debate about scale and terminology, not as a settled weapons-effects calculation.