"The Cold and The Dark"

Authors: Paul Ehrlich, Carl Sagan, et al.
Norton & Co, 1984
Apocalypse Type: Nuclear (Non-fiction)
Rating: **** (of 5)


The first major book to really explore the science behind the concept of nuclear winter, this is -- and should be -- disturbing.

In case you're just off the ship from Mars, nuclear winter theory is the idea that a nuclear war over a certain number of warheads will trigger temperatures to plummet, especially in Northern Hemisphere lands distant from the ocean, with drastic consequences to many species including humans. They don't specify what that threshold is because no one knows, but responding to questions at the conference this book records, Carl Sagan said, "I think that to take out all major fixed strategic targets reliably, you have to exceed the nuclear winter threshold" (p33).

Sagan's group, best known as TTAPS#, explored numerous scenarios of various severity including attacks solely on cities (called "countervalue" targeting), attacks solely on military targets (called "counterforce" targeting), and mixed attacks hitting both urban areas and military sites. Based on a wide range of variables -- many of which they admit they couldn't quantify, and simply labeled as "synergisms" -- and atmospheric effects partly modeled on the massive globe-spanning dust storms of Mars, they argued that almost any exchange will exceed this threshold. If that happens, the theory says it will spark average temperatures to fall and stay cold for a time in proportion to the size of the exchange; just a few degrees for small ones down to -47 deg. C for the most severe scenario, taking more than a year to return to normal in some scenarios. They theorize that a major part of the freeze is caused clouds of soot from fires making Earth's surface far darker than normal, possibly too dark for people to see or plants to photosynthesize.

There is good news here (if we can call it that): sparking a new ice age is highly unlikely. Still, "it's very hard to see in any of these scenarios a situation in which the impact on people mediated through the ecological systems would not be at least as severe as the direct effects," Paul Ehrlich writes (p65). (Ehrlich, a biologist, wasn't an original TTAPS member.)

What he means is this: a nuclear war's effects would harm humanity from two different directions. First, millions die from the direct effects -- blast, fire, and fallout. Those effects are fairly short-term. Much longer-lived, and far less predictable, are the climatic changes; the radiation-induced mutations causing new diseases and fertility problems##; increases in ultraviolet sunlight once the skies clear; widespread radiation & other pollution for years; widespread destruction of fertile cropland; loss of vast quantities of fuel, data and technology; and the ripple effects the massacre of large swaths of the world's mammalian, bird and other species we depend on for food and less obvious "environmental services."

"The total number of people afflicted would certainly exceed one billion and might include everyone in the Northern Hemisphere," Ehrlich writes (p52). (For a somewhat technical summary of why environmental services are important, see an article by Thomas Deitz and Eugene Rosa here.)

"The survivors will be back in a kind of hunter and gatherer stage. But hunters and gatherers in the past have always had enormous cultural knowledge of their environments; they knew how to live off the land," Ehrlich writes (p59). Given that most people today in the major target countries are city-dwellers, that kind of knowledge is pretty uncommon, a fact that will certainly result in the starvation of many of those who actually survive the war itself. I suspect, though, that people will cobble together locally-varying kinds of scavenging systems and maybe very basic agriculture once canned goods are depleted.

Obviously, this idea has detractors, some of whom have argued that nuclear winter is more politics than science. One of those detractors hs been author Michael Crichton, who said the following in a Caltech speech in 2003:

What I have been suggesting to you is that nuclear winter was a meaningless formula, tricked out with bad science, for policy ends. It was political from the beginning, promoted in a well-orchestrated media campaign that had to be planned weeks or months in advance.

Further evidence of the political nature of the whole project can be found in the response to criticism. Although Richard Feynman was characteristically blunt, saying, "I really don't think these guys know what they're talking about," other prominent scientists were noticeably reticent. Freeman Dyson was quoted as saying "It's an absolutely atrocious piece of science but…who wants to be accused of being in favor of nuclear war?" And Victor Weisskopf said, "The science is terrible but---perhaps the psychology is good." The nuclear winter team followed up the publication of such comments with letters to the editors denying that these statements were ever made, though the scientists since then have subsequently confirmed their views.

That may be true; in fact, it's quite clear a major goal of the TTAPS group was to influence public perception of nuclear weapons and to express their great dislike of the weapons. As Yevgeniy Velikhov put it, "They are simply tools of suicide."

Brian Martin presents a pretty complete view of the politics behind the debate, but ultimately notes:

Just because 'politics' may be involved with nuclear winter research does not automatically mean that the research is scientifically wrong, tainted or inappropriate for use in policy-making. A straightforward response is to be aware of the political context of the research when evaluating it. For example, if the peace movement has provided the indirect or direct stimulation for doing the research, this may suggest that other social movements (or other strands of the peace movement) might have provided the incentive for different research or different emphases in nuclear winter research. If the background and experiences of key nuclear winter researchers lead them towards certain presuppositions in their model-building, such as an emphasis on worst cases, then this is something to be aware of, not necessarily something to be condemned. If nuclear winter research is defended on the basis of verifications (different scientists finding the same results from similar models) rather than attempted falsifications because verifications are better suited to promoting the theory, the implications of this for policy-making should be discussed.

Personally, I'm inclined to view the whole issue this way: even if the theory is seriously over-representing the consequences, can we afford to ignore it? If it's wrong but we get rid of nuclear weapons assuming it's right, we're in good shape. If it's right and we do the same, we're also in good shape. But we lose if we have a nuclear war whether it's right or wrong; the only difference is in the severity of the subsequent catastrophe. I suspect even the most severe war and its aftermath wouldn't cause our extinction, but would leave enough survivors for human populations to adapt and stabilize long-term at a neolithic subsistence level. What I doubt is whether we'd ever rediscover an industrial society afterward, since we've already used most of the fuel supplies that allowed us to create one this time.

*****

# TTAPS comes from its members' names -- Turco, Toon, Ackerman, Pollack and Sagan -- but is also a pun on the military music for funerals.

## Sloan-Kettering recently developed a drug that prevents this in female mice, although it would be just as hard to find as any other drug after a war.

(entry revised 6/13/05)