‘The Dark Nuclear Winter’: Suicide of the Species

The Scene was a large Washington hotel conference room. There were very few empty chairs and very many television cameras. Scientists were making a two day presentation on “the world after nuclear war” — namely the long-term worldwide biological consequences of nuclear war after the half a billion people have died by the initial blasts and firestorms from the initial major weapons exchange.

Professors Carl Sagan and Paul Ehrlich made the summary reports on the first day and more specific analyses were conducted in panels on the second day. Many in the audience got the message on day one and did riot return.

It is a shocking message, made possible by new research using conservative computer models of what happens when massive tonnage of dust and smoke clouds moves into the atmosphere. The research involved dozens of leading scientists who did the basic work or checked their colleagues findings. In short there was extensive peer review at an earlier meeting this year in Cambridge, Massachusetts. There was very little disagreement among the physicists, climatologists and biologists regarding the general devastation.

The world’s nuclear arsenal today amounts to over 12,000 megatons (MT), which is enough to destroy one million Hiroshima-size cities. A one megaton nuclear weapon has the explosive power of one million tons of TNT. Scientists ran computer models of different nuclear war scenarios, including a 5,000 MT exchange and a 100 to 1000 MT war. Urban and industrial areas were among the hypothetical sites struck, along with hardened missile bases.

They calculated how much dust and smoke was generated; how much sunlight was absorbed by the dust and smoke; how much the temperature changed; how the dust and smoke spread, and how long before it all fell back to the surface; the extent of radioactive fallout over time; and how much ultraviolet light reached the surface after the soot and dust fell out.

From the-se calculations came the conclusions about “the dark nuclear winter.” Here are the biologists words: “The below-freezing temperatures, low light levels, and high doses of ionizing and ultraviolet radiation extending for many months after a large-scale nuclear war could destroy the biological support systems of civilization, at least in the Northern Hemisphere. Productivity in natural and agricultural ecosystems could be severely restricted for a year or more. Postwar survivors would face starvation as well as freezing conditions in the dark and be exposed to near-lethal doses of radiation. If, as now seems possible, the Southern Hemisphere were affected also, global disruption of the biosphere could ensue. In either case, the extinction of a large fraction of the earth’s animals, plants, and microorganisms seems inevitable. The population size of Homo sapiens conceivably could be reduced to prehistoric levels or below, and the extinction of the human species itself cannot be excluded.”

Freezing temperatures and a reduction of sunlight at ground level to a few percent of normal would destroy most cultivated food sources and farm animals. Surface fresh water would be frozen, available food supplies would be rapidly depleted and most of the human survivors would starve. Add the radiation, the waves of- fire, the epidemics, the near total breakdown of society, medical care, transportation and communications, and you can imagine the horrors the scientists are projecting.

Does all of this information add anything new? Yes. If these scientists are correct, and they hasten to add that the global effects may be much worse when more knowledge comes in, then various options become less likely. The Southern Hemisphere can riot be seen as an escape haven. Civil defense shelters become a cruel hoax. And the biggest strategic policy consequence from these studies is that even a “successful” major first-strike aggressor country, receiving not a single missile in retaliation, would be committing suicide from the boomerang atmospheric effects of their own nuclear weapons.

I asked Professor Sagan what minimum level of weaponry would generate this dark, cold “nuclear winter,” as he described it. He said the explosion of 1000 one hundred kiloton weapons or the equivalent of 100 megatons could launch the process. Even if the threshold level were 1000 megatons, that would amount to less than ten percent of the nuclear weapons of the Soviet Union andthe U.S.A.

Professor Ehrlich, on ABC’s Nightline program, said that all these years during which both superpowers were stockpiling nuclear weapons, these countries’ rulers were operating in ignorance of the global effects of a major nuclear war. In a word, the effect would be omnicide.

If the American scientists and Soviet scientists, who came to a similar conclusion, are accurate, there would be no such thing as a successful major nuclear aggressor even were the other adversaries Unable to respond to a major nuclear strike at all.