The Demon-Haunted World_ Science as a Candle in the Dark - Carl Sagan [139]
From my point of view, the consequences of global nuclear war became much more dangerous with the invention of the hydrogen bomb, because airbursts of thermonuclear weapons are much more capable of burning cities, generating vast amounts of smoke, cooling and darkening the Earth, and inducing global-scale nuclear winter. This was perhaps the most controversial scientific debate I’ve been involved in (from about 1983-90). Much of the debate was politically driven. The strategic implications of nuclear winter were disquieting to those wedded to a policy of massive retaliation to deter a nuclear attack, or to those wishing to preserve the option of a massive first strike. In either case, the environmental consequences work the self-destruction of any nation launching large numbers of thermonuclear weapons even with no retaliation from the adversary. A major segment of the strategic policy of decades, and the reason for accumulating tens of thousands of nuclear weapons, suddenly became much less credible.
The global temperature declines predicted in the original (1983) nuclear winter scientific paper were 15-20°C; current estimates are 10-15°C. The two values are in good agreement considering the irreducible uncertainties in the calculations. Both temperature declines are much greater than the difference between current global temperatures and those of the last Ice Age. The long-term consequences of global thermonuclear war have been estimated by an international team of 200 scientists, who concluded that through nuclear winter the global civilization and most of the people on Earth, including those far from the northern mid-latitude target zone, would be at risk, mainly from starvation. If large-scale nuclear war ever occurs, with cities targeted, the effort of Edward Teller and his colleagues in the United States (and the counterpart team headed by Andrei Sakharov in the Soviet Union) might be responsible for lowering the curtain on the human future. The hydrogen bomb is by far the most horrific weapon ever invented.
When nuclear winter was discovered in 1983, Teller was quick to argue both (1) that the physics was mistaken, and (2) that the discovery had been made years earlier under his tutelage at the Lawrence Livermore National Laboratory. There is in fact no evidence for such a prior discovery, and considerable evidence that those in every nation charged to inform their national leaders of the effects of nuclear weapons had consistently overlooked nuclear winter. But if Teller is right, then it was unconscionable of him not to have disclosed the purported discovery to the affected parties - the citizens and leaders of his nation and the world. As in the Stanley Kubrick movie Dr Strangelove, classifying the ultimate weapon - so no one knows that it exists or what it can do - is the ultimate absurdity.
It seems to me impossible for any normal human being to be untroubled by helping to make such an invention, even putting nuclear winter aside. The stresses, conscious or unconscious, on those who take credit for the contrivance must be considerable. Whatever his actual contributions, Edward Teller has been widely described as the ‘father’ of the hydrogen bomb. In an admiring 1954 article, Life magazine described his ‘almost fanatic determination’ to build the hydrogen bomb. Much of his subsequent career can, I think, be understood as an attempt to justify what he begat. Teller has contended, not implausibly, that hydrogen bombs keep the peace,