When Nutty Ideas Collide: SDI, Meet Nuclear Winter : Science: Two of the most goofy ideas in recent years combined to create something that benefited all mankind. Could this have been planned?
The year 1993 marks the 10th anniversary of two important ideas about nuclear war--the Strategic Defense Initiative, announced by President Ronald Reagan in a 1983 speech, and the nuclear-winter theory, pronounced a few months later by a group of scientists led by Carl Sagan. The premise of SDI was that nuclear warheads aboard ICBMs could be rendered “impotent and obsolete,” in Reagan’s phrase, by orbital defenses. The premise of nuclear winter was that nuclear warheads are even more potent than previously feared, capable of rendering obsolete all life on Earth.
In their early years, both the SDI and nuclear-winter concepts were passionately believed by some of the country’s most distinguished writers and opinion leaders. Most of the political right was adamant that SDI would work; most of the political left was equally adamant that a world-ending nuclear winter could happen.
A decade later, both SDI and nuclear winter are discredited. Only a handful of people remain true believers in either concept. Defense Secretary Les Aspin has announced a formal end to SDI as a Pentagon objective. The nuclear-winter hypothesis has been widely derided by scientists other than its authors.
Whenever assorted political figures and deep thinkers spout contentions with conviction, it is wise to remember the fates met by the SDI and nuclear-winter concepts: Ideas widely believed may, with amazing speed, be consigned to the discontinued rack of history. Yet, that’s not what is significant about the 10th anniversaries of SDI and nuclear winter.
What is significant is that, flawed and goofy as both ideas were, in the flawed and goofy realm of international events they combined to produce a tremendous benefit for society: nuclear-arms reduction. The START Treaty, signed in 1991 by the United States and the former Soviet Union, which reduces the superpowers’ nuclear weapons inventories by approximately one-third, was very much a product of the invalidated presumptions of SDI and the nuclear winter. This is a strange case where two wrongs actually did make a right.
Both these failed notions arose from interplays between technical discoveries and strong wish-fulfillment mechanisms of competing ideologies. In both cases, the original laboratory finding that made the notions possible were not held in the realm of detached science long enough to be analyzed objectively, but almost immediately transferred to the realm of politics--where they mutated into political instruments with poor technical justifications but, oddly, enhanced power to influence the political question of nuclear-arms reduction.
The SDI idea was given its technical underpinnings by some 1970s engineering work suggesting that, in principle, “directed energy” weapons such as lasers and charged-particle beams could be made powerful enough to destroy nuclear warheads across great distances in seconds or less. No laboratory tests had demonstrated any practical models, much less the network of computers, sensors, rockets and energy sources that would be necessary for a working SDI system. But the idea of beam weapons in space held an irresistible appeal to a broad coalition of technology fanciers, defense-spending advocates and those who, like Reagan, believed it was immoral to accept the idea that if nuclear deterrence failed, nations should allow themselves to be destroyed.
At the same time, an idea was gaining support in right-wing intellectual circles: If the United States, a rich nation, began spending like crazy on defense, the Soviets, a backward nation with the equivalent of medieval basket weavers trying to make supersonic bombers, would ultimately be forced to accept that they could never keep up.
But what to spend on? In the early 1980s, the United States already had so many strategic weapons it seemed insane to advocate building more. Then the conservatives working on the spending-race idea heard about the conservatives working on the SDI idea. It was a perfect fit. SDI could, everyone knew, be astonishingly expensive: Just what was required!
But SDI would be a defensive system--giving it a sheen of ethical virtue. Soon, despite misgivings from such quarters as White House Science Adviser George A. Keyworth, who in the early ‘80s kept trying to point out to Reagan that engineers had nothing remotely resembling a workable directed-energy weapon, SDI was rolling.
A kind of willing suspension of disbelief took hold--we began to assume that the Soviets would soon have space weapons, too, even though we ourselves had no idea how to build them. In 1982, for example, the Pentagon told Congress that the Soviet Union would have functioning laser battle stations in orbit by 1988 at the latest. Of course, no such battle station has ever been built. So far as is known, neither the United States nor the former Soviet Union ever even test-fired a directed-energy weapon capable of knocking down one nuclear warhead, let alone thousands. The closest thing to an actual test--a U.S. laser that heated the skin of an obsolete missile till it burst--was conducted against a non-moving target over less than one-thousandth of the distance that would be required in space-war circumstances.
But as the SDI notion was being advanced, something useful was happening. We knew that SDI might never be practical. But did the Soviets know it? They couldn’t be sure that we might not have a breakthrough they didn’t know about, and so the former Soviet Union began spending like the dickens on space defenses, too. Exactly as the spending-race theorists had predicated, the Soviet economy began to sense that an arms race against a rich adversary was a futile exercise.
Meanwhile, the nuclear-winter theory was budding. Its technical genesis came when Sagan and several other prominent astronomers used one of the then-newfangled computer climate models to estimate what a major nuclear war might do to Earth’s climate. Sagan and his colleagues supposed that the explosion of 5,000 megatons of nuclear bombs, less than the world’s doomsday arsenals, might put so much dust and smoke into the atmosphere that global mean temperatures could fall by up to 45 degrees Fahrenheit for an extended period, killing millions of sick and famished war survivors directly via cold, while destroying at least an entire year’s crops worldwide.
This, the Sagan team thought, might lead to an extinction of human life. Horrible as all-out nuclear war might be, no respectable scientists had previously documented the idea that it might end all human life. Popular culture images of the destruction of life after nuclear war, as in “On the Beach,” never had technical support.
As the SDI idea fell on fertile ground on the right, the nuclear-winter theory found the same on the left. Its premise was completed at a time when the nuclear-freeze movement was gaining in political power nationwide, and when the intermediate-range nuclear missiles, scheduled to be deployed by the North Atlantic Treaty Organization in Europe, seemed to many to be an invitation to begin Armageddon.
Also, development of the idea followed by one year the 1982 publication of Jonathan Schell’s book, “The Fate of the Earth”--a smash hit on the left for asserting that nuclear war would cause the extinction of life, and attacked on the right as an exercise in scientific illiteracy. Now came several famed researchers saying “The Fate of the Earth” might be right--and giving heft to the nuclear-freeze movement.
The catch to the Sagan team’s work was that their computer models were rudimentary. For example, the model essentially assumed away the effects of wind, clouds and other natural influences in moderating post-bomb smoke and dust. Though the model could not be calibrated against any real-world test, later, in 1991, Sagan used some of his 1983 assumptions to predict that smoke from the oil fires in Kuwait would cause falling global temperatures and perhaps “massive agricultural failures in the United States.” Neither happened.
But just as SDI had been rushed into the public arena long before any of it was proven, the same happened with nuclear winter. A technical paper supporting the idea was given accelerated-publication status at the prestige journal, Science. Sagan wrote a popular article on the idea for Parade, and a ponderous version of the same for the intellectual standby, Foreign Affairs. Belief that a nuclear winter had been proven, rather than advanced as a hypothesis, became common.
The idea of a functioning strategic-defense system took a decade to fall into disrepute. The nuclear-winter theory lasted less long. By 1986, climatologist Stephen H. Schneider, now of Stanford University, and his colleague Starley Thompson had shown that when the simplistic terms of the original Sagan team model were replaced with more refined assumptions, the prospects of an extended nuclear winter or human extinction declined to “a vanishingly low level of probability.”
Yet, just as Washington had talked so fervently about SDI that the Soviets believed we really meant it, they believed the nuclear-winter theory, too. After all, it came from the omniscient computers of the West. The notion of nuclear winter caused the Soviet military Establishment to re-examine its assumption that international socialism could survive a nuclear confrontation with the West. If everybody dies in a nuclear war, even the Politburo hard-liners began to think, what’s the point? What, indeed?
And so, by 1991, both U.S. and Soviet military planners, to say nothing of the political systems of each country, agreed to a momentous treaty that reduces the international inventory of nuclear warheads. The START treaty will be considered by history one of the best things that happened in the 20th Century. It is far more sweeping than the nuclear freeze, which seemed both a radical and unattainable idea just eight years before.
But that was before the prospects of SDI and the nuclear winter--two nutty ideas that did the world good--combined to make the arguments for nuclear arms reduction seem overpowering. There may never again be another instance when two unsupported ideas can combine to cause one worthwhile reformation: blending together the two screwiest notions of health-care reform or deficit reduction, for example, surely will not get us out of either of those muddles. But at least once, two wrongs did make a right.
