Fire and Ice: The Greenhouse Effect, Ozone Depletion, and Nuclear Winter.

DAVID FISHER, a Floridian professor of cosmochemistry," has produced a trendy introduction to the "greenhouse effect" and ozone depletion, but also addresses a third topic, one intermediate in its relevance and credibility between cold fusion an core, unreconstructed nuclear winter. The effect is like that of pouring a fine bottle of wine only to discover a dead mouse at the bottom, an effect considerably compounded if some of the wine has already been drunk with approbation, and has come from your own vineyard.

Fisher is certainly long on sour grapes where NATIONAL REVIEW iS concerned. The object of his wrath is Brad Sparks's polemic "The Scandal of Nuclear Winter" [Nov.15, 1985] an odd blend of expose and solecism that caused at least as much vexation to those of us trying to unravel the bag of worms Carl Sagan dumped into the pages of Science in 1983 as to Sagan himself

But just as Sparks's troubles stemmed from an inadequate familiarity with the scientific underpinnings of the debate, Fisher's reliance on dated, secondary, and often partisan sources has 149d him into a time warp populated only by a dwindling and increasingly incestuous band of nuclear winterists. With luck, he'll find his way in from the cold-even Senator Proxmire and the New York Times editorial notebook eventually caught on.

And, quantitatively, nuclear winter has suffered quite a crackup. Despite some heroic stonewalling by Sagan, the last remake of Gotterdammerung has turned out to be a very wee specimen of an apocalypse indeed. Here are the hard data-now that we've got some. (See graph.)

In 1983, Sagan & Co. told a systems programmer to turn the sun down or off on a computer model by opacifying its "sky." The posited cause of such a shift in what is termed "optical depth" was the presence of dust, smoke, and soot from a nuclear holocaust. The assumed amounts of dust and soot proved to be exaggerated, as was the clouds' lifetime in the air. In the case considered in the companion piece to Sagan & Co.'s "Nuclear Winter" article-"long-term Biological Consequences of Nuclear War" the optical depth was so great (more than twenty powers of e) that the solar flux at the earth's surface virtually disappeared for a Biblical forty days and forty nights. With the sun magically turned off, the temperature on earth then sank to 53'F. In Sagan's model, the earth then took over a year to thaw out. Of the resulting "biological consequences" it was written: "The extinction of homo sapiens cannot be excluded."

The direct and graphic comparison of these old predictions with those of newer and more elegant computer models is startling. They're now talking 50' above zero, on average, for weeks rather than a range of around the freezing point to 50' below zero for months or years. The numbers talk: it's the area between the old time/temperature curves and the new that counts, and nowhere this side of Palm Beach do just a few hundred heating degree-days constitute winter.

How has Fisher reacted to this 100 degree misunderstanding.? By pretending that non-scientist Sparks's effort at criticizing the theory was the final word. Also, by describing the editors of this journal as "charlatans" and "creationists"; to round out his voice of moderation, he says: "like the Nazis, they lie." Along the way he makes a number of order-of-magnitude substantive errors of fact. And trusting in Britain's left-wing Popular Science clone, The New Scientist, Fisher repeats a demonstrable falsehood of his own: that physicist Freeman Dyson's criticism of the nuclear-winter theory was never made. In reality, such a criticism was made, in 1985. To his credit as a scientific professional, Fisher retracted this allegation when informed of the facts, but, alas, it was too late for the falsehood to be omitted from the first printing of Fire and Ice.

In the seven years since the nuclear winter theory was first formulated, there have been as many variations on that theme as media for conveying it. One of its earliest renditions was a luridly eschatological television movie in the mid Eighties. And in this connection, some moments of candor by the theory's authors have later returned to haunt them.

For while scientific theories evolve, videotape does not; it has captured their apocalyptic rhetoric like a fly in amber. Some amazing things were said and, courtesy of the special-effects departments and animators of Hollywood, illustrated more vividly than they ever could be in the scientific literature. What the public was shown on television was the antithesis of the cautionary prose of the published scientific paper, with its confession of the underlying uncertainty of the data and the need for further study. And it was not in defending the theory's uncontroversial central premise (it does tend to be cooler in the shade), but in consenting to lurid (snow on the palm trees, ice floes in the Amazon) video effects that Sagan and others earned the censure of their colleagues.

Science was but the medium; the message came first. And it is important to consider the context of what grew into an object of dogma. Nuclear winter became a virtual sacrament in the secular religion of disarmament, something mentioned to this day with reverence and superstitious awe in the pages of The Humanist. Sagan and the rest of the elders of that curious sect, the Fellows of the Academy of Humanism, are a canny lot. Imagine their response on flipping the TV dial late one night to discovering a host of televangelists raking in the green while intoning that Armageddon and rapture are right around the corner as the millennium turns.

The end of the world is big at the box office, no matter how long the list of prophets of doom who have failed to deliver. But we needed a remake. And in one-upping St. John the Divine, the neo-fundamentalists' first step was to forget that the concept wasn't novel to begin with. Cooling due to dust and soot first materialized in John von Neumann's 1954 Senate testimony and Christopher Anvil's short story "Torch" (recently reprinted in After Armageddon, an anthology edited by Dr. J. E. Pournelle for Tor Books). Grandmal nuclear winter made its debut in the April 1957 issue of Astounding Science Fiction.

While Fisher has swallowed Sagan's bait and been dragged off behind the nuclear-winter bandwagon, he displays a commendable lucidity in wrestling with the dilemma of policy response to carbon-dioxide buildup. He affords the reader a painless introduction to the world of computer climate models along with some interesting examples of their use and abuse. (In the Seventies, global cooling was as fashionable as the greenhouse effect is today.) And unlike most of the organizations, environmental and otherwise, that Fire and Ice commends to the reader, Fisher clearly acknowledges the virtues of intelligently designed and competently run nuclear power plants. The environmental and human cost of mining and burning coal has clearly had a sobering effect on him.

Likewise, his chronicle of the ozone wars has the ring of truth-of science as it is, rather than as it is idealized. He chronicles the unsuccessful campaign to maintain that nitrogen oxides from the Concorde would lead to the collapse of the stratosphere's ultraviolet shield. There follows a clear exposition of the disturbing discovery of the ferocious efficiency of chlorofluorocarbons (CFCS, let loose as freon) in destroying stratospheric ozone by catalytic attack. For unlike the surreal soot-clouds of Sagan's ersatz apocalypse, some things that go up are a long time coming down.

Fisher falls short, barely, of joining the true believers who would declare an ad hoe atmospheric crisis and clap industry in macroeconomic chains before the scientific jury has delivered an indictment, let alone tried the case of Earth v. the Greenhouse Gasses. As well he might: until the role of the great-granddaddy of them all-water vapor-is better understood, the riddle of global climate change may go unsolved.

For many and subtle are the spirits of the air, hard to summon, harder still to exorcise. Thrift, in the form of market-driven improvements in fuel and energy efficiency, has few enemies, and CFCS in the high atmosphere have even fewer thoughtful friends. But we have already unleashed on the fragile stratosphere things that go bump in the night.

Fisher does fine when atoms and molecules are concerned, but he has a lot to learn about aerosols. We may hope that his next book will reflect progress along the learning curve, and an apprehension of the ultimate lesson of nuclear winter's rise and fall: having known sin at Hiroshima, physics was bound to run into advertising sooner or later.

Perhaps the shock of the collision will lead to more vigilance by science journalists and TV producers, but I'm not betting on it-not until political polarization of the environmental sciences fades away will there re-appear in the minds of the scientists a once and future thought: Science politicized is science betrayed.