A lecture given to undergraduates at St. John’s College, Annapolis, on March 27, 2019.

The End of the World

The Easy Part and the Hard Part

Half a century ago, and a bit more, there were events called teach-ins, informal lectures by experts on the then present emergencies, the name a play on that of the sit-ins by which the dispossessed were claiming their rights. You may, if you like, think of this as such an occasion, even though it does not displace a regular class. Nor am I an expert; rather, in good local style, I will be talking about some things I don’t know well, and may in consequence commit errors; but I will try to be accurate.

I am going to speak about the end of the world, the easy part and the hard part. I’ll start with the easy part, which is description, and even prediction; although, as they say, it is always very difficult to predict, especially the future.

What is “the world”? The wide world, the familiar world,—the world of children’s books, to begin with: it contains plants and animals large and small, water and land, ice and lava; there are the seasons, and there is the weather that belongs to them. Speaking for children, or of them, a poet wrote, “The world is so full of a number of things, / I’m sure we should all be as happy as kings.” In this full world people work, play, and struggle, live and die. That’s the world I mean, in space and time: familiar beings of all kinds are in their familiar places, and vary in their accustomed periods; as in the house of Gimme the Ax, “where everything is the same as it always was.” Now if everything is the same as it always was, then even though everything is always in flux, still what has been is what will be, and there is nothing new under the sun.

To the contrary, some of this world is gone; more is going; and what is not yet on the way may pass in a moment or gradually. My interest here is in human causes for this disappearance, so let me first set aside a number of others, which belong purely to fate.

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The universe, now almost 14 billion years old, keeps expanding, and ever more rapidly. If it does so forever, it may tear apart, and will get cold. But maybe it will collapse instead, or do something else altogether. —Oh, never mind the universe, whose life history remains quite obscure.

In a few billion years the Andromeda galaxy will run into the Milky Way, changing the sky, but perhaps not what is left of the solar system.

Eventually the sun, obedient to its nature, will incinerate the earth; and long before that, its slowly increasing luminosity will have done away with life. But not for some hundreds of millions of years.

Meanwhile, the earth’s hot core, whose energetic activity does much to distinguish our planet from a dull place like Mars, is very slowly cooling.

One day a supernova may perturb the earth, or a black hole swallow it; but none of these are presently noticed nearby. At one time it was feared that a powerful accelerator, such as the one at CERN, might create a hungry little black hole, into which the world would vanish; but the physicists argued that collisions in the accelerator would be weaker than the natural ones of cosmic rays with the atmosphere, and further, that little holes don’t last. Trusting argument, they went ahead to build and run the machines.

A large asteroid, or even some body from outside the solar system, may at any time devastate the earth, as has happened before. If its approach is noticed soon enough, it may be possible to deflect it, by applying a small nudge—if, that is, humans with high technology still exist.

From time to time the earth’s protective magnetic field weakens significantly, exposing life to dangerous radiation. Occasionally it falls to near zero, and reverses its polarity. The field has been weakening for some millennia; but how far and how fast it will fall, and whether other processes may mitigate the effects, is unknown.

Volcanoes now and then take out parts of the earth. Our Yellowstone, for example, promises to eliminate perhaps a third of the United States one of these years—a concern merely parochial. But extensive volcanic activity happening in a short period can darken skies and poison land and water, causing mass death worldwide, as seems to have happened in the past.

Enough of fate, let me turn to responsibility.

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1

The ever-present immediate danger is the one the prominent physicist Steven Weinberg spoke of a few years ago. “About the future,” he said, “my views are old-fashioned. I think the greatest threat to humanity is the enormous arsenal of nuclear weapons maintained by Russia and the U.S.” A nuclear war, if large enough, would kill an appreciable fraction of the world’s living things quickly, and not a few others more slowly, by sickness and in other ways—perhaps by damage to the ozone layer, or somewhat in the manner of volcanism, by throwing up so much smoke and soot so high as to produce nuclear winter, a darkness—so far merely conjectural—that would last long enough to kill the plants, and hence the animals, including humans. So-called low-yield weapons have recently come into favor; these are as powerful as the Hiroshima bomb, concerning which one may read John Hersey’s unforgettable little book; they beg to be used, because they are relatively small, and the strategic thinkers can find no persuasive reason why an adversary would respond to small nukes with much bigger ones. Many years ago a certain one of these opined soothingly that the chance of nuclear war in any given year was a mere 2%. Assuming, as this thinker did, that the chance in one year is independent of the chance in another, it would follow that the likelihood of war in 35 years is more than 50%, and in 70 years is more than 75%.

Cousin to the bomb is the nuclear power plant, which arouses much concern. Like an isolated volcano, it can do harm that is severe and long-lasting, although most deadly only nearby. In contrast to such a device, the vast nuclear arsenal is protective—so we are assured.

2

It is more fashionable these days to fear what the spin doctors call climate change, and I call climate ruin (see my post of Dec. 10, 2018). The cause is simple: the sun sends us light in short waves, which pass through the air and warm the earth; it then emits heat in long waves, which cannot readily pass through certain gases in the air, notably carbon dioxide and methane. When enough heat can escape, a steady state of average Earth temperature is possible; but humans have been doing much burning, and burning makes carbon dioxide, so its concentration in the air is increasing, and therefore more heat is trapped within the atmosphere; as a result, rather than a steady state, we have increasing temperature on Earth. To make matters worse, thawing the permafrost (naïve name!) releases methane, which traps still more heat, which causes more thawing, and so on. This is an example of a feedback loop, in which the effect of a cause strengthens the cause and so magnifies the effect.

The increase in temperature has a great variety of consequences, of which only some are recognized, partly because the energy called heat may transform unexpectedly into other forms, such as the kinetic energy of wind, and partly because feedback loops are hard to foresee. A goal has been proposed, to limit heating to 1.5° Celsius, which is 2.7° Fahrenheit; but it is unknown whether the climate can stabilize at that level. There may occur what is called a runaway, uncontrolled feedback leading to extreme conditions. If the heating is not limited, the runaway becomes all but certain. One way in which this is predicted to happen is by the loss of clouds, which now cover about two-thirds of the planet at any time, and reflect sunlight back to space. Heating seems likely to reduce this cloud cover, hence less light will be reflected, heating will increase, and so on, producing perhaps another 8° C.

Ice too reflects, and is melting; although the reduction in its brightness will be less noticeable than other consequences, especially the sea level rise that will drown our cities, among other places, and the shrinking of glacier-fed rivers, particularly those that flow from the Himalayas. These water some two billion people in Asia; as they dry up, those people will move, or die—no doubt both. A recent UN estimate was that to have a hope of staying at 1.5° C, drastic action must be taken over the next 12 years, no more. (Of the 12 there now remain 11 1/2.) With such action, still a third of the Himalayan glaciers will be gone in 80 years. With moderate action, half; with no action, two thirds.

And it should be noted quite generally that every new investigation of a process of climate ruin seems to find that it is happening faster than previous investigation had led us to believe.

3

Both of these dangers, war and heat, threaten to make the earth uninhabitable—to destroy our habitat, and that of the other creatures too. But even apart from either one, habitat loss is proceeding apace, driven especially by agriculture in the broadest sense, whose increase is demanded by a growing human population. Land and water are contaminated with human debris; living things are killed outright or driven into confines where they cannot survive. An example that has received some attention is called the windshield phenomenon. When I was a boy, on a long summer vacation drive along the highway one had to clean the windshield from time to time, to remove the flying insects that it had met. But when I took a long summer drive recently on the Eastern Shore of Maryland, my windshield killed no insects—they were dead already, prey to chemicals and to the replacement by human monoculture of the various plants that had supported their lives. I need hardly speak of other cases, such as that of the microplastics most creatures now carry within them, or of the thin floating continents of plastic that have become established in the oceans, like sterile Sargasso Seas; while those oceans themselves are becoming more inimical to life, not only on account of contamination, but also because warm water holds less oxygen than cold.

4

In connection with war, heat, and habitat loss, the possibility of widespread disease should be acknowledged. For humans, at any rate, as long as there is high technology, disease may be suppressed; at the same time, that very technology bids fair to produce diseases specifically designed to resist suppression. Another kind of feedback loop can be envisioned: disease severe enough reduces the forces that can control disease, and so on.

5

Lastly, I will mention the potential exhaustion of mineral resources, which are squandered without a thought for time to come. There is helium, for example, the second element in the periodic table; a finite quantity of it exists underground; released, it is gone forever, lost high in the atmosphere. Its value for science, and for technology, is great now, and could be greater in the future. It is used to fill party balloons. And there are very rare elements, of which more than a dozen are being distributed into smartphones, because they have not yet run out.

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The once and briefly famous Secretary of Defense, so-called, Donald Rumsfeld is remembered for these remarks: “As we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns—the ones we don’t know we don’t know.” The last of these, he thought, are the difficult ones. Well, we knew that. But he left out the case by which our weakness condemns us: the unknown knowns. These are things we know, but don’t know we know, because we avoid the pain of knowing them. So we go about our lives, acting in ignorance of the things we know.

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Now for the hard part. Can something be done?

Will technology save us? Not from the other human evils, surely, but from climate ruin, at least? I can’t say that this is impossible, but in the time available, it looks unlikely. How ironical, that many of the very people who disbelieve the conclusions of scientific research harbor a deep belief that technology can be relied on to solve all problems. —To be sure, would-be geoengineers are offering proposals, such as imitating perpetual volcanoes by continually spraying large quantities of sulfur dioxide into the atmosphere to darken the world, and hoping that there will be no dreadful side effects. Can we rally behind that? Then too, something not yet dreamt of in our philosophy can never be ruled out; but to expect better dreams is idle.

Will God save us? No, for against our petition he puts forward an unanswerable defense: he pleads nonexistence.

So we can’t hope to make it up to heaven; can we at all events do as the dinosaurs did, and take to the air, so to speak? They left the earth’s surface to become birds. Having spoiled Earth, can we—a few of us—fly away to another world? Even if we wanted to—even if we cared only to save our own species—it is doubtful that we could, for a multitude of reasons, of which it is enough to mention, besides the vast distances, the deadly radiation that suffuses space, which might well render survival impossible for any travel long enough to get anywhere desirable.

If civilization should collapse, could it be rebuilt? Not to its present level; you get only one shot at that. To say nothing of worse obstacles, there is the simple fact that once the necessary minerals have been dispersed, they cannot readily be found again.

So the human evils I have discussed have to be fought. Had we but world enough, and time, the battle would not have to be joined here and now; we have not. It is necessary to act, before “The cloud-capp’d towers, the gorgeous palaces, / The solemn temples, the great globe itself, / Yea, all which it inherit, shall dissolve.”

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Now here you are, at a school where your elders tell you what to do and when to do it; so it would be natural for you to expect direction at this point. But I cannot provide it: this is your fight. Half a century ago and more the principal fights were over the war in Vietnam, and civil rights—which many of us regarded as a single movement—with, of course, the bomb waving its dark wings over all. Back then there was a slogan, “Don’t trust anyone over 30.” I didn’t care for that slogan even then, when I wasn’t over 30; but it had a point. I hope you can trust old folks for various purposes; but they can’t tell you how to save your world, or do it for you. —You are wondering, what did I do, back then? I didn’t do very much, but I didn’t do nothing, either. One time I was begging money from faculty members at my university for some worthy action or other, I forget what, and I was not having much luck, until I asked a certain professor, John Ward by name (a British physicist of distinction, and a character); he gave me $10, which would be $80 now, saying, “Always glad to support anything subversive.” Indeed, I could trust him to support us, but not to direct us. It was our fight.

Your fight is harder and more desperate. The stakes are higher, and at least for climate ruin, time is short. Governments must act; for individual action in isolation, admirable as it may be, hardly begins the work. Recycle all your plastic every day, the world will still go to hell. Persuasion via the usual channels has its fundamental place, but will not be enough; one has to make trouble, too. All kinds of action are called for, action that can compel the needed response; and governments will resist any move that threatens them, resist it fiercely. As a rule, those in power are interested primarily in their own continuance, to which end they are wonderfully resourceful. They are practiced in rationally justified resistance, in passive resistance, in pure deception, in every tactic; their resistance knows no bounds, and they are always ready to turn to violent repression.

For example, at the reasoned end of the scale comes the kind of thing the American government kept repeating long ago, that citizens should not presume to urge withdrawal from Vietnam, because the situation was far too complicated for ordinary people to understand, so that policy had to be left to the experts; to which a sufficient reply was, we may be unqualified to determine whether it is better to leave on a Tuesday or a Friday, but we are quite competent to judge that we ought to get out forthwith. A nice recent local example of resistance was this: a few years ago many tutors signed a petition requesting the Board, which is ultimately our government, to divest of fossil-fuel stocks; in answer it was politely explained that the college was but a small investor in a great conglomerate, so insignificant there as to have no influence over its investment decisions, hence nothing could be done. On with business as usual. —As for governmental violence, examples are all around us; I need give none.

What is before you is as hard as can be. If you strive, as you must, you will not at first succeed; you will fail, and lose, again and again: we drove out Lyndon Johnson, hero of civil rights, but villain of Vietnam—“Hey, hey, LBJ, how many kids did you kill today?”—only to get Richard Nixon. Yet the war did end, civil rights did advance, treaties reduced nuclear weapons (though not nearly enough) and, incredible as it may seem, four countries that had the weapons actually gave them up. So there is hope in rising, and rising again, to fight, as only you can know how.

“We shall nobly save, or meanly lose, the last best hope of earth,” said Abraham Lincoln, as if in prophecy for these times, which are yours. And for the life-and-death struggle now underway, no less than for those of the past, it is godlike Sarpedon who offers the best encouragement, free of all illusion: “Ah friend, if once escaped from this battle we were for ever to be ageless and immortal, neither should I fight myself amid the foremost, nor should I send thee into battle where men win glory; but now—for in any case fates of death beset us, fates past counting, which no mortal may escape or avoid—now let us go forward … .”