The Nuclear-Winter Debate
Jill Lepore’s article about the history of climate science and nuclear-winter theory is important, but her story is incomplete (“Autumn of the Atom,” January 30th). Although Lepore states that the nuclear-winter debate has “long since been forgotten,” research done in the past ten years, using modern climate models, has shown that the theory of nuclear winter—which says that smoke from fires started by nuclear detonation will block sunlight, causing the Earth to become drastically colder—was correct. Lepore also refers to Stephen Schneider’s alternate theory of nuclear “autumn,” from the nineteen-eighties, as if it refuted the nuclear-winter theory. But it failed to take into account the Earth’s stratosphere, was never published in a scientific journal, and was certainly not accepted by the scientific community. It was, however, used by supporters of nuclear weapons to try to discredit nuclear winter.
Despite the over-all decrease in Russia and the U.S.’s nuclear arsenals, the two countries still have the capability to produce a nuclear winter: a nuclear war that used less than one per cent of the current global arsenal would cause a climate change unprecedented in recorded human history. Let us hope that this summer’s U.N. negotiations to ban nuclear weapons will make it clear that a nation threatening retaliation or a first strike would be acting as a suicide bomber.
Alan Robock, Rutgers University
New Brunswick, N.J.