You Might Want to Know: Are They Useless? XVII-Nuclear Winter? Really?
This is the last entry on this question
Some very large explosive volcanic eruptions—like the Samalas eruption in Indonesia in 1257 and, in more recent times, the eruption of Mount Pinatubo in the Philippines in 1991—had propelled enough material up through the atmosphere and into the stratosphere to cause significant cooling in some areas of the earth. Large areas. For long enough sometimes to cause crop failures and famines.
The atmosphere—where our weather happens—is not as thick as we may think. Sixty miles. You could drive that far in less than an hour without speeding.
In the early 80’s, some scientists here in the U.S. and in the Soviet Union realized that an exchange of nuclear weapons might cause something similar to what the volcanic eruptions had caused, but worse—an effect they called “nuclear winter.”
For decades after the invention of nuclear weapons in 1945, the possibility of nuclear winter had gone unrecognized. For most Americans, the possibility of nuclear winter was first brought to notice by two articles published in 1983 in Foreign Affairs and Science, journals whose intended readers were not scientific experts but the educated general public.
Nuclear winter wouldn’t be a direct effect like blast, heat and ionizing radiation. Nuclear winter would be an indirect effect.
It was a significant drop in temperature on earth caused by particles that had been driven up through the earth’s atmosphere into the stratosphere by nuclear detonations. And, more significantly, by the firestorms that would result from those detonations.
The particles—soot, mostly—that reached the stratosphere would be above the weather that might bring them back down to earth. They would linger up there. Estimates differed for how long.
While there, the particles would prevent the sun’s energy from reaching the surface of the earth. Not all of the sun’s energy, but a enough to make a difference.
Those who called it “nuclear winter” believed the cooling would be severe enough to create winter conditions around the world for at least a year, maybe even for a decade. Those who called it “nuclear autumn” had decided that the cooling wouldn’t be that bad or last that long. Still bad, just not that bad.
Winter or autumn conditions lasting for a decade, or even for a year, would be not just uncomfortable. If they lasted for only a year, the world’s food supply would be destroyed, first plants then animals. We’d starve. Some of us. Maybe a lot us. Maybe all of us.
When nuclear winter was finally recognized by scientists as something that could happen, discussions began about how many nuclear weapons would be needed to make it happen, how likely it was to happen, and how damaging it would be. If it happened, it would be widely damaging. That wasn’t debated, though exactly how widely was.
There still isn’t solid agreement among scientists about any of these matters. But no one has been able to show that something like nuclear winter wouldn’t happen.
How many nuclear weapons could make it happen? Detonated in what places?
Today, the most likely scenario for a nuclear exchange between countries is widely thought to be one that would take place between India and Pakistan. In 1991, Michael Mills, a researcher at the US National Center for Atmospheric Research, told Business Insider that 50 Hiroshima-sized weapons from each country would trigger nuclear winter.
An earlier calculation was that an exchange of 100 nuclear weapons with the medium-sized yields of the weapons both countries are known to have, 50 to 100 kilotons, 4 to 7 times the size of the Hiroshima bomb, would cause 2 billion people to starve. And not just in India and Pakistan.
How does that compare to what could happen if there were a larger nuclear exchange?
A study published in April 2022 claims that the winter resulting from a general nuclear war between the United States and Russia would kill 5 billion people worldwide. Leaving about 3 billion of us. Here and there. To make our way in the new world.
Where would the weapons have to be detonated? In Mills’ scenario, it was assumed each warhead or bomb would strike a different city. It didn’t matter which cities or in which countries, as long as the cities were as big as, say, Hiroshima, about 250,000 people at the time.
The firestorms are the key. Cities wouldn’t have to be the targets. Forests could do in a pinch.
If we aren’t inclined to engage in the specific details of the scientific debate about nuclear winter, what do we need to know?
That the risk of nuclear winter is real. No study I know has shown that that the risk of nuclear winter is not high, and from a nuclear exchange far smaller than we might think.
Nuclear winter is another effect that makes nuclear weapons useless for military purposes:
Nuclear winter also makes it impossible to distinguish between military and civilian targets.
Nuclear winter would result from enough detonations on enough cities, no matter what countries those cities were in. Even if they were all in the same country.
Like the fallout nukes produce, nuclear winter makes it impossible to confine the effects of the weapon to particular countries. The harm nuclear winter would cause would, however, be much more widespread and quicker acting than that caused by fallout.
The United States now has fourteen Trident submarines. Each can carry 24 missiles. Each missile can carry as many as 12 warheads. Each warhead is capable of yielding more than 400 kilotons, 26 times Hiroshima. Each can be sent to a different target. That means every Trident submarine can yield 8700 times more than Mills was imagining.
How many nuclear winters would the firepower of one Trident submarine cause?
No one knows of course.
One would do the trick.
National sovereignty and national borders are a political obsession in some quarters. “Secure borders” are viewed as absolute and inviolable, a sine qua non of national identity.
Nuclear winter is another effect of nuclear weapons that makes the most simple-minded versions of these ideas…what…quaint?
Needing thoughtful revision, at least.
With the next posting, we will begin another series on Presidential Predicaments produced by the nuclear arms race, this time those experienced by President Eisenhower.