The Devastation of ‘Nuclear Winter’
The dreadful wildfires that ravaged the forests in California and other parts of the West, while causing much devastation, managed to serve science. They have yielded information concerning a scientific controversy that may be of the greatest importance to the survival of humanity.
The controversy had its beginnings in 1980, when it was first suggested that an asteroid or comet, 10 miles across, may have struck the Earth 65 million years ago and produced a disaster that destroyed much of life on Earth, including all the dinosaurs.
As the years have passed, evidence in favor of such a strike has accumulated, and while there are still questions and disagreements, most scientists seem to have accepted this explanation of the dinosaurs’ demise.
Naturally, the question arose as to why such a strike, formidable though it may have been, should have killed all the dinosaurs. If the collision took place at a particular spot, why should life have been destroyed on the other side of the world, too?
The answer is that such a strike would have produced results that would have affected the whole world. If the asteroid had plunged into the ocean, there would have been tidal waves that would have ravaged all the coastlines of the world. If it had punctured the Earth’s crust, the vastness of the volcanolike eruption would have started forest fires that would have spread over much of the world. And there are indications of such tidal waves and widespread fires having taken place at the time.
Moreover, there would have been so much dust thrown up into the upper atmosphere by the strike, and smoke from the forest fires as well, that the sun’s light would have been prevented from reaching the Earth’s surface for a period of time. The cold and dark that would then have prevailed (an “asteroid winter”) would have killed most of Earth’s vegetation and the animals that depended upon it.
Then, beginning in 1982, some people began to wonder whether an all-out nuclear war might not produce similar effects. Imagine thousands of nuclear bombs being exploded on Earth. Each one would create a fireball that would start a conflagration. Each one would cast tons of soil into the air. No one of them would do the damage of a single asteroid strike, but all of them together, striking in different areas of the Earth, might do so. The dust and smoke in the upper atmosphere might start a “nuclear winter” that would kill vegetation and starve animal life--and then we would go the way of the dinosaurs, quite literally.
If this scenario is true, then the tens of thousands of nuclear bombs accumulated by the superpowers can never be used. Even if one side managed to carry through a sneak first attack that crippled the other side and prevented retaliation, there would be no victory. The nuclear winter would then destroy the untouched power as well--and all the neutrals.
The question is, though, would a “nuclear winter” really result? Those people who fear a nuclear war naturally think it would. Those people, on the other hand, who feel that the threat of a nuclear war must be maintained for defense, think it wouldn’t and that the fears are being deliberately exaggerated by soft-headed pacifists.
Nor is there any good way of testing the matter. You can’t explode a vast number of nuclear bombs just to see what would happen. And you can’t argue just from theory since that wouldn’t be convincing to those who refuse to believe.
But now Alan Robock, a meteorologist of the University of Maryland, has reported on the effects of the Western wildfires of the summer of 1988. Smoke emitted from those fires was trapped over some valleys in Northern California and Southern Oregon by an inversion layer. Smoke accumulated there for three weeks.
Naturally, this created respiratory problems for people, so that more than 400 persons had to be treated each day.
More important, however, was that there was a cooling effect. Daily maximum temperatures on the valley floors were lower than normal by more than 9 degrees Fahrenheit over that three-week period. During the worst week of the interval, temperatures were down by nearly 30 degrees Fahrenheit.
The cause of this phenomenon was the burning over the period of a month of 80 squares miles of forest. There have been estimates that in a nuclear war more than 80,000 square miles of forest would burn. The burning of industrial plants, oil refineries and so on would add additional smoke of a worse type.
This careful study of day-to-day temperatures in the case of ordinary forest fires certainly makes it seem that a “nuclear winter” cannot be ruled out. In addition to the immediate deaths by the explosive blasts of a nuclear war, and the slower, more agonizing deaths caused by radioactive fallout, there would be almost universal starvation as a cold darkness fell across the world.
My feeling is that we face a clear choice. The world must live in peace, or it won’t live at all.
