|A book by|
William H. Calvin
UNIVERSITY OF WASHINGTON
SEATTLE, WASHINGTON 98195-1800 USA
The Ascent of Mind
(Bantam 1990) is my book on the
ice ages and how human intelligence evolved; the
"throwing theory" is one aspect. |
My Scientific American article, "The emergence of intelligence," (October 1994) also discusses ice-age evolution of intelligence. Also see Wallace S. Broecker, "Massive iceberg discharges as triggers for global climate change," Nature 372:421-424 (1 December 1994) and his "Chaotic Climate" Scientific American article (November 1995 issue).
|AVAILABILITY is challenging.
Many libraries have it (try the OCLC on-line listing), but otherwise its strictly used bookstores (and German and Dutch translations).
The Ascent of Mind|
Ice Age Climates and
the Evolution of Intelligence
Copyright ©1990 by William H. Calvin.
You may download this for personal reading but may not redistribute or archive without permission (exception: teachers should feel free to print out a chapter and photocopy it for students).
Has Intelligent Life Evolved Yet?
Nature evolved our sense of purpose blindly, but now we have it. That sense of purpose has given us dominion over the biosphere. We, who were not created, have become creators. We are ignorant and fallible, and like any other animal our minds work best in the short term and the bodily scale. We do not think clearly in megatons or picture generations much beyond our grandchildren. Nonetheless, the earth has become our garden; it behooves us to cultivate it with wisdom.the ethologist Alison Jolly, 1988
The ferry slips through a narrow channel separating Shaw and Crane Island, sailing westward out into San Juan Channel; Orcas Island is now behind us. San Juan Island itself comes into view, a large wooded island with the mountains of Vancouver Island in the background. A dozen sailboats wander about the broad expanse of San Juan Channel, and a commercial fishing boat chugs along. Turn right here, and youll soon cross the international boundary into Canadian waters. We turn left and lose the view of the mountains.
Indians used to live among these islands, mostly fishing but also hunting and gathering. Indian villages hereabouts tend to disappear over the centuries, as theyre usually fishing villages like the one on Whidbey Island that is eroding out of a headland; once a century, a fierce winter storm is likely to sweep such a village away, unless it has been buried in the interim by a landslide.
And outsiders who write history and take photographs of the Indians have only been around here for a little over a century. They did, fortunately, record the words of Chief Seattle (for whom the city is named), who in 1854 was reported to have said:
The air is precious to the red man, for all things share the same breath the beast, the tree, the man, they all share the same breath. The white man does not seem to notice the air he breathes. Like a man dying for many days, he is numb to the stench....
What is man without the beasts? If all the beasts were gone, man would die from a great loneliness of spirit. For whatever happens to the beasts soon happens to man. All things are interconnected.
This we know. The earth does not belong to man, man belongs to the earth. This we know. All things are connected like the blood which unites one family. All things are connected.
The biologists and climatologists have finally discovered just how true that is, but were having trouble selling the stewardship idea to the rest of the world.
American settlement here did not involve great wars with the displaced Indians, so far as I know. Of course, European settlers usually unknowingly spread smallpox to the immunologically defenseless Indians. Since their microbes preceded them, Europeans competed with much-weakened tribes. (Perhaps, in revenge for smallpox, the Indians gave the Europeans tobacco?)
The San Juan Islands are a special place, even in the history of warfare. They are largely inside the United States, though the archipelago extends through Canadian waters alongside Vancouver Island and on up north into the Gulf Islands. The international boundary represents one of the sterling examples of how to resolve international disputes. In the middle of the nineteenth century, when settlers were just starting to farm the islands, both the Americans and the British claimed the islands since nationals of both countries were living here. A dispute over a farmers pig caused settlers to take sides and this led both the British and the American governments to send some troops here. They never fought each other. They merely established garrisons, the English on the north end of San Juan Island on the shores of a pleasant bay, and the Americans on a windswept ridge near Cattle Point at the south end. The English planted an orchard around their little camp; the American soldiers got the view of the Olympic Mountains and the Strait of Juan de Fuca. It is not recorded who won the sporting contests that they organized between the troops during the 12-year occupation.
Eventually the dispute was submitted to arbitration: Kaiser Wilhelm of Germany drew the international boundary line in 1872, which survives to this day. The so-called Pig War could serve as a model to other nations about how bloodlessly to settle disputes.
FROM A FORESTED SHORELINE of nature preserve (with Mount Baker having reappeared on the left side), suddenly one turns right to see a town ahead. "Friday Harbor," announces the disembodied voice. "Friday Harbor," it repeats in that "time to wake up" tone of voice that streetcar conductors use to announce the end of the line.
All along the right shore is the University of Washingtons Friday Harbor Laboratories. My wife did the research for her Ph.D. thesis here, and Ive lots of experience visiting. I look back into the forest along the shoreline at the apartments nestled into the rocks. I well remember the spring of 1980, while we were up for a weekend, sleeping in one of the mobile homes hidden even further back, under the trees. We had gotten used to the sound of pine cones falling on the metal roof during the night. But after daybreak, we were awakened by a boom that shook the room. An earthquake? (We had once had our bed shaken in the middle of the night by a small earthquake while at Friday Harbor.) But this was too noisy for an earthquake: I leapt out of bed, convinced that someone had backed a car into the side of the mobile home.
As I stood in the doorway contemplating the complete lack of candidate cars, several more booms shook the place. But the ground seemed stable and the trees didnt sway. My wife, as puzzled as I was but busy trying out possible explanations, wondered aloud if someone was firing the cannon that they use to start the boat races. I didnt think that the racing committee had recently acquired the guns from a battleship: that was an awfully deep-throated boom. The previous year on sabbatical in Jerusalem, I had developed an ear for judging the sound of explosions most of which turned out to be dynamite explosions for digging basements in the rocky ground, not terrorist bombs. This sounded more like an ammunition dump going up.
While hurriedly getting dressed, I got on the shortwave radio network (the local amateur radio community has situated a repeater atop Mount Constitution over on Orcas Island, and so even the little handheld radio in my briefcase could reach long distances) and asked if anyone else had heard the explosions yes, indeed, people in Victoria had heard them, and in Bellingham too. And then a distinctly Canadian voice came on; he reported talking to an amateur radio operator in Portland, Oregon, who had looked out his window. And observed that Mount St. Helens had blown its top.
Mount St. Helens is 280 kilometers (175 miles) from Friday Harbor, near Washington States southern boundary just as San Juan Island is at its northwest extreme. Could we see the eruption? It seemed unlikely, but we drove to the south end of San Juan Island; from Cattle Point there is often a clear view south into Puget Sound. On the drive down, we stole glimpses of Mount Baker, just to our east no ominous steam plumes, fortunately.
Looking south from Cattle Point, the overcast seemed featureless. Then, between two layers of clouds in the south, we saw a mushroom cloud rising, just when the radio reported another big eruption. It was three times as high off the horizon as the highest mountain peaks; we almost missed seeing it because we were looking lower with the binoculars. That ash was clearly being injected into the stratosphere. The morning blast was 500 times greater than the atomic bomb exploded at Hiroshima (but was small stuff compared to the prehistoric eruptions at places like Oregons Crater Lake or Californias Mono Lake region).
That same spring at Friday Harbor, the throwing theory occurred to me while I was throwing stones at the beach, trying to find excuses for why I was so inaccurate. Its progeny, the Darwin Machine and the cortical consensus, have not been associated with any ominous rumbles or thunderclaps, so far.
Well, a friend reminds me, at least if you dont count Californias 7.1-rated earthquake in 1989. I spoke to a group of computer designers at a summer camp, located in an interesting place: on the San Andreas fault in the mountains between San Jose and Santa Cruz. And on a similarly risktaking topic: How to build a "conscious" computer using Darwin Machine principles. The earthquake was centered only a few miles away but it came three days after my talk. If God was trying to tell me something, her reflexes were a little slow.
WE DONT NEED AN OCCASION to visit Friday Harbor but this time there is one, not Darwin Machines but a gathering of the friends of the late Graham Hoyle at one of Grahams favorite places, the Friday Harbor Laboratories.
Graham, professor of biology at the University of Oregon at the time of his death, firmly believed in studying the nervous system from the vantage of behavior, but also digging deeply into the electrical mechanisms of nerve and muscle. He solved the problem of how insects seemingly manage to violate the sodium-in, potassium-out rule of all nerve cells. He also was probably the first to discover the role of potassium currents in modulating neural excitability during learning, now a hot research area.
Trained in the British tradition of vigorous academic debate, Graham often made those trained in more polite traditions (if you cant say something nice, dont say anything at all) a bit uneasy. Graham could always be counted on, at a scientific meeting, to stand up and ask a pointed question, often softened with self-deprecating humor. Many of us learned to love him; neuroscience meetings just arent the same anymore, without Graham.
The ferryboat cruises past the Labs on the way into Friday Harbor, the only town on San Juan Island, the second-largest of the San Juan archipelago. Here one can see what wasnt evident from that over-the-ice-ages flight from Copenhagen. Though much of the shoreline of the harbor is becoming developed (and the Port of Friday Harbor is always pile-driving to create an endless maze of pleasure-boat moorages obstructing the old harbor), the north shore is largely a nature preserve. In one small part of this preserve is situated the universitys research station, a collection of buildings nestled into the rocks and trees by a sensitive and skillful architect, and a wooden pier extending out into the harbor.
There are a few boats moored on the pier, plus a commercial-sized fishing boat. The motor boats are for collecting animals and algae. The rowboats are available for transportation into town, whenever researchers or students develop an irresistible longing for beer or ice cream. But the days of leaving the rowboat on the town beach are long since gone: no beach remains. These days, you have to consult a map of the maze just to discover the three places where one is allowed to park a rowboat temporarily; if you forget to check the map before departing the Labs, you could row forever around the Port of Friday Harbors moorage maze, seeking a temporary haven.
More frequently, the rowboats are used just to get a little exercise: Graham always used to end a long afternoon at the microscope by launching a rowboat and vigorously rowing across the harbor to Brown Island and back.
THERE IS A DEER nibbling away at some greenery outside the library. I am sitting on the balcony of the library, enjoying the view of the water and Mount Baker and was taken by surprise by the sound of the deer behind me in the trees. One of the charms of working here is that you can look up from peering into a microscope or book, glance out the window to rest your eyes, and find a pair of big brown eyes watching you.
Or a pair of little black eyes. One has to keep the doors to the labs closed, as whole families of raccoons will come in and help themselves to all that live food swimming around in the seawater tanks; they are particularly fond of small crabs. It is a similar fondness for shoreline creatures that probably led some other land mammals back into offshore waters, reinventing some aquatic specializations. When I see these raccoons out on the shore at low tide, poking their paws into the tide pools, I think of seals and aquatic apes.
But deer arent quite as adventuresome as our raccoons deer swim between islands occasionally, as the ferryboat crews can attest (thats probably how the Irish elk arrived in Ireland during the Allerød warming of Europe only to be killed off 1,500 years later by the Younger Dryas cold spike), but deer arent fishing along the way. Swimming is probably a once-in-a-lifetime thing for most deer; without natural selection for daily foraging in the water, the deer arent likely to develop aquatic adaptations very soon.
The Fernald Building at Friday Harbor Labs is a modern two-story wood-and-glass structure tucked into a rocky recess in the waterfront, blending with its natural surroundings in a way that few architects ever attain. I once started describing this building to architecture professor Robert Small as the modern building I most admired in the world and he confessed that he had helped design it back in the fifties, as an assistant to Ralph Anderson. The library on the upper floor is an idyllic place to work. Its carrels run around the windows, big plate-glass walls on the two sides that face the harbor. An exterior walkway balcony runs all around the buildings upper floor, and on the harbor side there is a long bench as part of the balcony. So one moves back and forth from library desk to the long park bench in the course of a day of reading and writing.
And if one wishes to stretch ones legs a little more, the balcony walkway leads off the west end onto a great craggy bluff of bedrock scraped clean by the Puget Lobe and more recently filled in with pads of moss, some soil, and some grass in those natural depressions that tend to hold the rainwater. Multicolored lichens cover the exposed rocks like a patchwork quilt. One sees Mount Baker sitting on the eastern horizon beyond the harbor entrance. The sea gulls often hover over the bluff, flying into a breeze.
Once a great blue heron stood offshore of the bluff for a long time, admired by me but being pestered by the gulls until it finally let out a series of loud complaints and flew away in disgust, settling down again in the little cove of the nature preserve, its feathers still ruffled. Birds have learned that size isnt everything; they often "mob" birds that are much larger than they are. I once saw a lone crow mob a bald eagle, chasing the U.S.s emblematic bird for several minutes reminding me, alas, of the way that the U.S. Congress had once again been frightened away from a rational discussion of population policy by a vocal minority opposed to birth control devices.
Humans have been around here only since the last ice age; western civilizations tenure is a mere one percent postscript to a long succession of Indian tribes. We scientists are intruding on the deer and raccoons that meander among the trees and buildings, the rabbits that (at least this year) render lawn mowers superfluous hereabouts. The birds remind us that small dinosaurs are still with us; the giant Puget Sound octopus reminds us of an entirely different evolutionary route to cleverness.
But our civilization is a startling postscript, if simply because of the accelerated time scale on which our cultural evolution operates and our tendency to remake the land on a scale approaching that of the volcanos and glaciers. Were also likely remaking the weather on a slightly slower time scale my guess is that we just havent noticed the disruptions yet.
THE HOYLE MEMORIAL SYMPOSIUM broke up at five oclock this afternoon, so that its participants could go out for a row, just as Graham always did at that hour. There was even a rowboat race, though not as far as Brown Island (they settled for a buoy in the harbor).
Some people, contemplating evolution and where it is going, suggest that the next stage of evolution is a giant group mind, using the same darwinian principles of shaping up variations on a theme, but with individual humans being the contributors to the larger "organism." Some suggest the economy as a model, having a life of its own. I usually reply that every scientific meeting that I attend seems especially like a superorganism the group mind has already been invented! There is something about meetings of only a few dozen people at Friday Harbor; they seem to resonate somehow.
Science as a whole is much more than any one of its contributors can fathom; it seems to have a life of its own. Lots of variations occur in the individual minds of its contributors, are shaped up there, and are usually shaped up further by checking against nature in experiments. But it is not a finished work, for when a scientist presents a talk on the work at a meeting like this, a lot more shaping up (or throwing out) goes on, since the other scientists have different information in their heads. New variations on a theme occur (sometimes you can even see a wave of them pass through the audience, as various people start to raise their hands to interject comments), and so the concepts get further shaped and refined. Though science is the best example I know, any subject with a marketplace for ideas art, literature, technology works this way too.
Yet in this candidate for a supermind, there is no decision-making apparatus equivalent to clone dominance in a Darwin Machine, nor is there a "super-individual" that lives or dies as a whole depending on how good its collective judgments are. A concept, viruslike, enters into a race for reproduction instead, perhaps being amplified by copying almost like a cancer metastasizing in other scientists heads (Richard Dawkins in The Selfish Gene usefully defined "memes," contributions to culture to be mimicked). There it either grows by additional contributions, or it lingers, or it dies out perhaps to be rediscovered twenty years later in another country when the environment for it is more likely to lead to copying. For better or worse, science is so international these days (thanks to easier travel and better communications linking us together) that national fads are declining, and there is less likely to be a protected niche for a new idea, so that it has a chance to develop before being overexposed to the competition for attention.
Earth system scientists have predicted that, as a direct consequence of increased carbon dioxide levels and the resultant greenhouse effect, storms will become more numerous in the coming decades, and they will be far more severe, with winds in excess of two hundred miles per hour (high atmospheric temperatures will accelerate evaporation, which will speed up atmospheric convection currents). Droughts will become common in the middle latitudes; rivers in the American Southwest, for example, may shrink by as much as forty to seventy-five percent, all but obliterating agriculture. And polar ice will begin melting, causing sea levels to rise by as much as two hundred feet and submerging such highly populated coastal areas as Hong Kong, New York, and Rio de Janeiro. The specter raised by such changes, at least in the minds of some scientists, is that man constitutes a threat to the global processes that, until now, have maintained the conditions necessary for life.Edwin Dobb, senior editor of The Sciences, 1989
WHEN SCIENTISTS GET TOGETHER to hash out recommendations on something such as the greenhouse effect or abrupt climate change, they usually retreat to a conference site and marine labs such as Woods Hole or Friday Harbor are a favorite of the biologists and oceanographers. Someday these very meeting rooms are likely to see a critical meeting in the history of the world, where new knowledge is evaluated, scientific opinion solidifies, and policy-makers pose questions.
Will new knowledge save us, or will the boom-time-breeders, the know-nothings, and the life-is-a-big-party types bring us down after all? Since no one is in charge here (or rather everyone is in charge and time may be too short for educating enough of us), one is led to hope against hope for a new stewardship force in nature that will protect the planet from the inappropriate ice age psychology and reproductive physiology of five billion humans, the same way that the Gaia system is said to buffer the atmospheric oxygen to keep it in the life-giving range.
Platos solution to such problems would have been a dictatorship of the enlightened, but weve seen what usually happens with rule by the few, even if they start off well-educated and well-motivated. The political arena has its hazards, to be sure: special interests using highly-selected data to confuse and confound the nonscientist, for example. Weve recently seen how someone can ignore millennia of data, concentrating on only the last thirty years, ignore the proxy climate indicators and just concentrate on weather bureau temperature records, ignore the world-wide data and concentrate on only the U.S., to make a headline-grabbing case for "dont worry." The fluctuating nature of the underlying processes makes it inevitable that countertrend periods will exist, as well as periods of confusing data especially when that data is taken in isolation. While we always have to assume that our data is incomplete and new data could arrive tomorrow that would cause us to reconsider, both scientific and political perspectives need to be world-wide, long-term, and sensitive to whole ecosystems.
Most of the climate-change imperatives are identical to those required by depletion of fossil fuels and by famine-producing overpopulation trends; wed need to do most of them even if the greenhouse factors disappeared somehow. Promoting political wisdom in a positive sense in this area is not easy to do. You can see the dilemmas in the greenhouse debates starting to take place, trying to define the choices to be made down the road. And were not even yet discussing long dikes or high technology, just which research opportunities we will chose to emphasize with our limited scientific budgets.
The need to invest in massive studies of the ocean-atmosphere-ice systems, and in the large computers needed to simulate their modes of operation, seems particularly obvious. But the studies of human physiology and psychology are perhaps as important, insofar as they affect our ability to modify overpollution and overpopulation tendencies.
And some such areas have been neglected in a way that will reflect very poorly on us, one of these days. In reproductive physiology the emphasis has been on proximate mechanisms of fertility. Despite the decades of awareness about the population explosion and the repeated examples of the cruel famines that follow runaway population growth, the real action these days is in vitro fertilization augmenting fertility by solving infertility problems.
Why is that? Though worthy of a humane societys concern and certainly making a few couples happier, its probably not what a survey would identify as a high priority among the worlds problems. Rather, we see an example of "thats where the money is," what we can expect more generally if basic research is further "privatized"; public research money has been very thin and unreliable, and a major source of single-issue private funding can redirect a whole area of basic research. The U.S. government, in particular, has often been unwilling to support most basic and applied research in human reproduction and has routinely turned away requests by other countries for aid in reducing birth rates with known techniques.
We can, if we choose to so convince our elected officials, greatly expand our support of research and education about birth control and research on understanding ultimate causation, such as those boom-time shifts that, without higher education and careers for women, induce urban children to hurry up and become 28-year-old grandparents. Understanding boom-time psychology and physiology might provide us with some ways of stabilizing the worlds runaway growth and implementing a "quality not quantity" ideal.
Life must move forward,
but it can only be understood backward.Søren Kierkegaard (1813-1855)
A WALK ON THE EDGE OF THE UNIVERSE is how I used to think of my nocturnal wanderings, when Id stroll out the top of a breakwater projecting one block into Lake Michigan. Id be surrounded by water, set off from the business of the Northwestern University campus, with the night sky overhead and the waves lapping underneath, the breezes whistling past my ears.
That was back in the Sputnik days of the late fifties, when only one artificial satellite at a time circled the Earth, and Id always watch for a slowly moving star. I was of the generation that had gathered on rooftops with binoculars, in the cold of the early winter mornings of 1958. And tried to imagine a lonely dog orbiting overhead, the first animal to leave the Earth. Later I discovered that breakwaters were nicer than the freshman dormitory roof. One could pace, to the rhythm of the waves.
Walking on water while contemplating the heavens, complete with a human addition. Exhilarating stuff, as was what I was learning every day. After several years, in spite of having dutifully read "a little learning is a dangerous thing," I decided that the only two truly fundamental scientific endeavors were cosmology and brain research, those inquiries into how we came to be. I picked brains. Without those breakwaters, I might now be an electrical engineer.
But instead Im a neurobiologist caught up with evolutionary problems, now taking another nocturnal stroll, this time along the breakwaters at the Friday Harbor Labs. They are three concrete floats, each about thirty paces long, that are anchored offshore from the main pier and which protect the plants and animals. Not from the occasional winter storms, as you might initially suspect, but rather protect from the everyday wakes of the passing ferryboats, seaplanes, and speedboats. A series of gangplanks connects the main pier to the breakwaters, and one can walk more than a city block before turning around and retracing ones steps, still surrounded by the open skies, intimate with the talking waves that lap against the floating path.
THE EMERGING VIEW OF HUMANITY is hardly a Garden of Eden. It implies that we humans pretty much invented ourselves, imperfections and all, and are still inventing ourselves. It implies that we are responsible for ourselves and our planet, that we can no longer blunder about like an energetically curious child poking around inside a clock with a screwdriver, confident that everything will be made right by an all-capable parent.
Our ability to modify our environment has gotten considerably ahead of our ability or at least our resolve to look ahead. It took us a little while to understand what fossil fuels do to the atmosphere and what DDT does to bird shells, yet we go right ahead introducing new chemicals in bulk quantities without the slightest idea of what they will do to the natural ecosystems on which our descendants will rely.
All of this rapid change during our lives has led to a boom-time psychology and physiology that entices us to exploit the opportunities of the moment rather than investing for the future. This opportunistic aspect of our basic biological heritage, shaped by the ice age population explosions, is winning out over the predicting-the-future abilities that might avoid the bust that usually follows the r-shifting boom.
One sometimes hears "the world would be better off if we were all still hunter-gatherers," that civilizations havent really been worth it after all. There is something to be said for that viewpoint, at least as it pertains to the average civilization, as the physiologist Jared Diamond noted:
Archaeologists studying the rise of farming have reconstructed a crucial stage at which we made the worst mistake in human history. Forced to choose between limiting population or trying to increase food production, we chose the latter and ended up with starvation, warfare, and tyranny. Hunter-gatherers practiced the most successful and longest-lasting life style in human history. In contrast, were still struggling with the mess which agriculture has tumbled us, and its unclear whether we can solve it.
Furthermore, civilizations arent as progressive as they usually appear in the history books. Perhaps twenty agricultural societies have, in the history of this world, progressed to the point of building cities (thats the basic definition of a civilization), the first ones about 5,000 years ago. In all but one, innovation toward widespread technologies was a minor thing, occurring early in the civilizations lifetime (if at all) and then reaching a plateau with little further "progress." Even in the Greco-Roman civilization that lasted from 600 B.C. to A.D. 400, most scientific advances and technological innovations occurred before 250 B.C. In terms of improving peoples lives, most agricultural societies were not a clear improvement on the life of the hunter-gatherers. Though, it must be remembered, a half-dozen civilizations did make considerable philosophical-scientific progress, just without translating it into technologies that benefitted people.
In one of the twenty civilizations, during the medieval-to-modern period that followed the Greco-Roman in Europe, technologies became widespread. Even in the "Dark Ages," horse collars and water power became commonplace. And the Renaissance gave birth to a few centuries of intellectual ferment, which led to the Scientific Revolution and the Industrial Revolution. Their products and some of their ways of thinking spread subsequently to the older civilizations of Africa, Asia and the Americas.
Certainly the world since the Renaissance has become a far better place; I cannot but think of how helpless people have felt with toothaches, dying children, mental illness, and starvation and how much sheer knowledge has improved the situation for many of us since the "good old days." But the fact that it only happened to one of those twenty civilizations doesnt give us much reason to assume that the re-emergence of a humanity-benefitting civilization would be inevitable, should we lose our science and technology in the rampages accompanying a collapse of our civilization. We cant count on a future civilization retrieving what we lose through poor stewardship.
That men do not learn very much from the lessons of history is the most important of all the lessons of history.Aldous Huxley (1894-1963)
I WAS PUZZLED by some high thin clouds in the sky tonight above Friday Harbor. They moved around too quickly for a night with only a light breeze. And one "cloud" developed curtain-like folds in a matter of seconds, brightened into a whitish-green of sorts and then stayed bright for several minutes. Whereupon it suddenly faded out, disappearing in less than two seconds.
I finally realized what was happening: those werent clouds but rather the aurora borealis, the northern lights. I havent seen them for three decades, not since my under- graduate years pacing on the shores of Lake Michigan. There must be a great storm in progress on the sun, sending even more charged particles streaming out into space. Those that get trapped by the Earths magnetic field give off light as they slow down, the whitish-green light coming from excited molecules of oxygen, after a solar particle has passed by. As much as two-thirds of the sky is sometimes covered by flickering aurora at one time; you cant miss it.
It is quite a show, those rapid changes in the aurora within seconds. A friend who grew up in Alaska once told me that they used to see bands of light darting across the sky, that some people even claimed to hear it snap and crackle during such whiplash performances. One wonders what the Paleo-Indians, who hunted and fished their way across the Bering Straits, thought of such displays whether they attracted them to the northern latitudes or made them hesitant to venture into such a realm. One can imagine the campfire councils of elders in Siberia, debating whether to retreat south or carry on toward those crazy displays in the northeastern skies.
In less than an hour, the aurora has faded out, the performance over. And I am left contemplating the backdrop: the Universe. The waters along the shore are advancing and retreating, like little fast motion versions of the ice ages. Im thinking about how any educated person can now know things about where humans come from, about how consciousness might arise, about how the heavens work, about how to prevent deadly diseases such as smallpox. Though imperfect descriptions, many a philosopher of the past would have sold his mother into slavery for a glimpse of them, and kings would have coveted a book describing them.
That our brains are capable of comprehending all this seems a result so out of proportion at least, compared with the mundane "causes" that are offered as explanations for the evolution of human consciousness. But then emergent properties are usually a surprise, at least until youve seen a few additional examples. Anatomy may seldom take leaps, but physiology more frequently engages in a "conversion of function in anatomical continuity."
OTHERS HAVE, despairing at what humans are doing to this planet, concluded that the Earth would be better off without us presumably on the assumption that a wiser creature might evolve from other forms of life if we werent filling such a big niche.
But, quite aside from my inherent preferences for human companionship and my ingrained suspicion of any counsel of despair, I think that this attitude is a big mistake. It assumes that what we value intelligence, ethics, creativity, stewardship, alleviation of suffering, whatever is some universal principle of nature that will inevitably rise to the fore again as the mill of evolution grinds finer.
I also think it dangerous to conclude, as some do, that the "infiltration of mind into the universe will not be permanently halted by any catastrophe or by any barrier that I can imagine." It is not merely that one should be skeptical of these on Goulds Principle ("Always be suspicious of conclusions that reinforce uncritical hope and follow comforting traditions of Western thought") but that such pronouncements soothe us exactly when we should be alert. There is some evidence for cleverness and reciprocal altruism as being not-uncommon results of the climate fluctuations that open up new niches but no evidence whatsoever that they regularly lead to intelligence or ethics, much less creativity or stewardship. Or that if they do, that they will be translated into widely beneficial technologies.
On present evidence (which is approximately sufficient to suggest that weve still got a lot to learn), Id have to conclude that intelligence, ethics, creativity, and stewardship are chance developments in just one side branch of the great bush of species that our ancestors invented them, that they could be easily lost by happenstance, that the chance of their ever being re-invented during the lifetime of our sun is nil. We humans invented them and we can, through poor stewardship, destroy them permanently.
The conservative assumption is that "we are it" that there is no backup intelligence who will conserve what we value if we ourselves let it slip. This is not a counsel of despair an avowal that the heavens are lifeless and empty, and humans ephemeral but a stratagem of "God looks after those who look after themselves" while we further explore the universe of mind and matter, acting as responsibly as if we were gods ourselves.
Disturbing thoughts one hazard of taking a long walk at the seashore under the starry skies.
And so as we go whirling and twisting into the future, which by God we could swear we did not make....Norman Mailer, 1969
LOOK-AHEAD SCENARIO-SPINNING is one of those uniquely-human characteristics such as music and dance, such as our versatile language. While chimpanzees may occasionally plan ahead a few minutes, as in the chimp who deceived his companions with a false food-cry, we humans are always planning ahead to tomorrow.
While the ice ages gave us the brains with which to plan ahead, we havent in fact planned very far ahead in the past, not much further than providing for our children over the next decade. Weve recently begun to plan centuries ahead, but only because we know the half-lives of our radioactive waste. Coping with a Dryas-like abrupt climate change, a frigid or arid millennium arriving within a few short years, may be the biggest challenge we have ever faced, and it remains to be seen if we have a brain capable of coping with the situation engendered by our overpollution and overpopulation.
For the last quarter-century or more, we have had the computing power to make working models of the atmosphere, one reason we can now estimate how long it will take for Arrheniuss greenhouse catastrophe to come true if we continue cutting down the forests and burning both them and the fossil fuels. Though a half-life only requires a simple calculation, other predictions are more complicated, as we have to make a working model of the processes involved. This use of simulation is unlike the familiar cockpit simulations for airplanes, which give pilots-in-training the ability to make mistakes harmlessly in real time. Instead we try to speed up time, so as to see what will happen to the system, but in a fraction of the time that the real thing takes to occur. That way we can observe the stabilities and dangerous oscillations after the computer crunches away for hours and days, simulating the complicated mix of processes. In physics, it was once thought that the important processes of the universe could be captured in a series of equations: Maxwells equations, Einsteins, or those of quantum mechanics. Now we think in terms of simulating the processes, as only simple ones can be captured in equations.
Fast-motion simulation is augmented look-ahead, expanded consciousness. For the greenhouse warming, weve simulated fifty years ahead and not liked the prognosis. The 12°C (22° F) heating of the high Canadian latitudes suggested by the simulations so far is particularly worrisome, as this seems liable to rearrange the jet stream across the U.S., which in turn affects the movement of humid Gulf of Mexico air up into the agricultural Midwest, etc. And to release the tundras huge quantities of methane (natural gas) upon thawing, thereby augmenting a greenhouse effect even more. From greenhouse to more greenhouse.
Good old positive feedback or so it would seem. But qualitative arguments are always a little iffy, because words can be slippery. They serve to alert you to the need for a quantitative argument, and therefore massive simulations, collapsing decades of real time into months of computer time.
The records of the last 150,000 years... scream at us that the earths climate system is highly sensitive to nudges... By adding infrared-absorbing gases to the atmosphere, we are effectively playing Russian roulette with our climate.the geophysicist Wallace S. Broecker, 1989
Ice core data of Dansgaard et al Nature 1993. Younger Dryas shown in red. Note the two episodes during the warm period 130,000 years ago.
THE ABRUPT CLIMATE CHANGE in the relatively recent past, merely 11,500 years ago, leads one to ask how often these things normally occur, even without a greenhouse warming. My count of the published records from the Greenland ice cores is roughly 20 cold spikes in the last 120,000 years for the North Atlantic region. And so that is 40 sudden changes, either sudden cooling or sudden warming, every 3,000 years on the average. It seems urgent that we use simulation to help figure out whether we might accelerate mode-switching behavior with our rapid forcing of the climate (via greenhouse gases), whether we might (as the first round of such simulations of the North Atlantic Current suggests) trip one of those abrupt climate changes.
I fear that what were currently doing is the equivalent of one of those Hollywood depictions of a test pilot climbing into the brand-new experimental plane, revving it up, zooming off the runway, doing a few barrel rolls and screaming dives, and then landing to the adulation of television cameras. No test pilot (or employer thereof) would dream of doing such a thing. They would slowly drive down the runway, observing how the plane handled at taxiway speeds. Then a week later they would run the plane up to takeoff speed but abort the takeoff. After eventually taking off and flying around a little, theyd try slow turns, working up to higher accelerations in slow steps, looking carefully for any signs of instability and backing off from it. They know perfectly well, as does anyone experienced with nonlinear systems, that the surest way to discover something that you wont like say, a tail spin or the airplane shaking itself apart is to make changes quickly, to do something equivalent to those screaming dives or steep climbs.
Any sensible approach to changing the Earths climate would emphasize very slow changes, retaining the ability to back off from any sign of an instability. Our present changes are rapid, almost abrupt. And our ability to back off is limited by the population boom: Humanity seems to take immediate advantage of any little improvement in living conditions by creating more mouths to feed and so makes it very hard to back off on our carbon dioxide and methane production.
Various business-as-usual pundits have been heard to say that we should wait before taking action against greenhouse gases, until scientists are "more certain." They fail to recognize that scientists are typically uncertain: like the "But on the other hand" of ordinary discourse, scientific uncertainty is a mental technique that we use to make progress, constantly questioning the adequacy of any explanation that hasnt already survived a few decades; such uncertainty has to be distinguished from the broad scientific consensus that we are seriously polluting the atmosphere and modifying climate. Dont rock the boat of economic boom times, the pundits say, totally missing the point: Continuing the way we are heading is simply reckless; it means that those leaders are quite willing, in order to maintain present comforts a few more years, to take irresponsible risks with our childrens future. It is our present course and speed that deserves the pundits skepticism; with a serious warning of shoals ahead, one slows down the ship rather than waiting for the first sighting. Or impact.
I do not believe in a fate that falls on men however they act; but I do believe in a fate that falls on men unless they act.G. K. Chesterton (1874-1936)
THIS AFTERNOON I heard several commonplace examples of mode-switching behavior as I was reading in the library. First, because the sailboats tend to turn around when they get close to this shore, I heard sails flapping and looked up to see a large sailboat as it was turned into the wind. Anytime a sailor tries to sail too close to the winds direction, the sails start flapping from one position to another ("luffing"). Sometimes the boom even swings across the centerline when you dont want it to, heading toward a new stable position (and trying to take your head with it).
Then later while I was typing up some notes, I heard an outboard motor being shut down after one of the collecting boats came back to the Labs dock. I didnt have to look up: I know that engine! The motor wouldnt die: it kept restarting itself after coughing to a near-standstill. Auto mechanics call it "run on" and readjust the carburetor so that the engine dies immediately after you turn the key off. Neuro- physiologists who study epileptic seizures comment on "motorboating" too: the tonic phase of a seizure runs down the "batteries" of the nerve cells to the marginal point and so they stop firing, then suddenly resume, then stop again. This is what produces the clonic phase of a tonic-clonic seizure: the patient may first be rigid, and then begins jerking spasmodically. His brain is motorboating (among other things).
Whenever a nonlinear system is changing from one stable state to another, it may go through a transition zone where it chatters back and forth, something like a faulty light switch that cannot decide whether to stay on or off. Chatter can be avoided by good design, as has happened with the most reliable of bistable devices, the flip-flop of digital circuits (which constitutes the basis of modern computer memories). But for most of evolution, including human brains and planetary climate, the good-enough solution hasnt eliminated a chattering zone.
Such may explain the European transition from full glacial times 20,000 years ago to the ice-free conditions of 8,000 years ago: Europe was lagging behind the Southern Hemisphere in warming up during the 15,000 to 13,000 year period. Then, within only a fraction of a century, Europe warmed a few degrees as if catching up: this "warming spike" is what is called the Allerød event at 13,000 years ago. Then, of course, at about 11,500 years, Europe flipped back to cold for 800 years (the Younger Dryas "cold spike"), then suddenly warmed (and continued warming more gradually into the interglacial). So the complete flip up-and-back-and-up again took 2,300 years. [1994 Update: The current dating of the Younger Dryas onset is 13,000 years ago rather than the 11,500 mentioned in this 1990 manuscript. And the abrupt climate changes are even more frequent than then appeared: see Wallace S. Broecker, "Massive iceberg discharges as triggers for global climate change." Nature 372:421-424 (1 December 1994). For updates on El Nino, see El Nino tuitorial from NOAA.]
Most of the cold spikes in the last 120,000 years in the North Atlantic have probably lasted several centuries, rather than the eight centuries of the Younger Dryas. And even more rapid ones could have occurred without our knowing about it yet. Really rapid spikes are something that researchers will be looking for, as they analyze cores with newer techniques. Some didnt take Dryas-like flips seriously for decades ("Just noise in those pollen records") because such layers didnt show up in all the various kinds of cores; spurious readings are one of the things that scientists have to guard against. But the seafloor (and likely some lake-bottom) layers had, alas, been smoothed out by the worms; their churning of the ocean floor served to smear together the sediments from over 6,000 years, obscuring any rapid fluctuations.
Worms are the original time-averaging machines. While the ice layers and the tree rings havent been similarly stirred, they too tend to "average" adjacent years, as the layering isnt watertight. And scientists often ignore the rapid change that gets through, if it doesnt fit their notions of slow trends (the most notorious example is when the Nimbus satellite program missed detecting the dramatic "ozone hole" that developed near the South Pole in the early eighties; in analyzing the data radioed down, its scientists programmed their computers to disregard as spurious any departures from the norm of more than a few percent). For many reasons, records of sudden change were likely lost; we have to assume that abrupt shifts are even more frequent, that weve seen only the more dramatic ones.
If we gradually change the parameters in the equations, the behaviour of [a typical nonlinear living] system will also change gradually; for example, if the behaviour is to oscillate, then the period and amplitude of the oscillation will change gradually. But ultimately, as we continue to change the parameters, we reach a threshold, or "bifurcation", at which the behaviour changes dramatically: for example, the system may cease to oscillate, and start to grow exponentially [or vice versa]. This, I take it, is a mathematical description of the change from quantity into quality. When one has played with a few systems of this kind, one has a better feel for how things are likely to behave.the mathematical biologist John Maynard Smith, 1988
FLIPS ARE THE FOREMOST REASON why I worry about the rapid warming of today: we have no information about what modes lie ahead, how our climate might jump. The Earth on its own has never explored the region into which were heading, at least not in a comparable way, and we have no idea what strange chattering is likely to develop on the way there. Judging from the history of the last ice age, Europe is particularly prone to mode-switching but then the North Atlantic is far better studied via ocean-bottom cores than oceans elsewhere, and it has the worm-free Greenland ice sheets to provide a second glimpse of its history. The Pacific Ocean might well have such mode-switching too, perhaps an exaggerated version of El Niño-to-La Niña cycling.
If climate change happens gradually over a centurys time, we can imagine coping but if it keeps flipping back and forth, well be like a country fighting a war on two fronts, frantically shuttling troops back and forth and generally disrupting civilization at the same time. Except well be trying to build new dams and pipelines, grow new forests, build new cities a centurys tasks compressed into a decade, all while combatting famines and the political instability that goes with them. And then the climate flips again (probably without warning), and everything has to shift to another front, such mammoth tasks being repeated elsewhere if we are able to muster the efforts required (a 99 percent decrease in population might be more likely).
About the only way out of the Dryas-style threats to humanity that I can see is if we become considerably more conversant with boom-time reproductive physiology and psychology. And considerably smarter through the use of computers, coming to understand the coupling between the ocean currents and the regional climates well enough to simulate them. Occasionally there is a bonus from predictive simulations: Sometimes you also learn how to give the system a little push in a desired direction. Even in simple systems, such as when pushing a child on a playground swing, there is a right time and place to apply an effective push.
For nonlinear systems such as ocean currents with all their eddies, it is harder to know when and where to push. But modeling may show how to try, suggest the amount of power needed. As chaos studies have illustrated, little changes can sometimes have big effects down the road. Perhaps by heating up an island-sized patch of ocean surface at the critical place and creating some more space-occupying back-eddies, a mode-switch will be prevented by plugging the alternative path. Seeding the clouds, in the manner we try to clear the December fog off of airport runways in Seattle, might allow the sunlight to heat up the ocean beneath. Or we might station satellites in space, big mirrors that reflect sunlight down on that patch of ocean. Or we might cool or warm the ocean by managing the planktons productivity in the surface layers.
If the deep-water production off Iceland became marginal, we might encourage the evaporative losses that create the hypersaline sinking (and so attracts even more North Atlantic Current up from the tropics) via spreading chemicals on the surface. Augmenting the evaporation rate is what the Israelis do in their southwest corner of the Dead Sea, to speed potash production. If modeling could tell us where and when to spread the surfactants, such a maneuver in the North Atlantic might help stabilize a shaky system, stave off a revisitation of the Younger Dryas.
Via some such maneuver, we could conceivably get ourselves out of this mess, at least for a little while. If we succeed, it will be because weve made a good working model of the system and played around with scenarios for the future, seeing which is best, and figuring out how to implement it. Thats the exact same procedure, on a larger scale, as a college student goes through when trying to select a suitable career. Its what family planning attempts to do. Its the business plan that the bank wants to see before lending money.
It is not what the apes do; like people who "live from hand to mouth," apes may plan an hour ahead but seldom organize for tomorrow. These computer models will again extend the time scale of human consciousness: from decades to centuries, perhaps even to millennia. They will get us into the alternative-futures business in a big way. Conceivably this next step in human evolution will also save our civilization.
Abrupt climate change could happen tomorrow, at the rate were jostling the system via burning fossil fuels, cutting forests, producing methane and refrigerator gases (most of which are secondary consequences of more mouths to feed, not inadvertent technology). So I dont mean to sound optimistic. The state of the modeling art, and the size of computers, is still a generation or more away from this kind of detailed knowledge.
And science itself is far too small an enterprise, given the size of the population and pollution challenges, plus the chattering climatic ones. The allowances that parents give their children for spending on candy and popular music are likely more than governments provide for all of basic science. To combat the problems that overpopulation and overpollution are earning us will probably require a quadrupling of the scientific enterprise, at the least. Plus the kind of public planning that, heretofore, has only occurred in time of war: its only a little matter of overhauling our entire agricultural-industrial-transportation system, worldwide.
DESPITE OUR PROFESSED CONCERN with the value of human life, we seem to be asking for really serious trouble, of the sort that causes famines and revolutions and, at the same time, prevents effective technological response by destroying economies and the scientific enterprise. Humanity has greatly overextended itself in the last few decades, largely via population growth and its associated cutting and burning of the forests.
Foresight used to be a frill, a spare-time use of the neural machinery for throwing or language, something our ancestors would occasionally use instead of a traditional, gene-encouraged behavior. Then foresight made possible our plan-ahead consciousness; it greatly expanded our niche and evolved our technological, science-based culture (not to mention greatly expanding worry and suffering). But now an augmented version of foresight has become essential, if we are to extract ourselves from this mess weve made of the earth and its climate. That we should need major climatic plan-ahead to get ourselves out of the situation created by the minor plan-ahead abilities arising from climate fluctuations thats the great irony.
The fickle climate giveth, and the fickle climate taketh away. I somehow doubt that we will appreciate the poetic quality of "our just desserts," should we not meet the challenge. The earths ocean-atmosphere-biosphere system is reminiscent of an Old Testament god lots of rules and no mercy.
To go along complacently in the face of greenhouse and population developments recalls "Typhoon," the Joseph Conrad story that tells of the imperturbable Captain MacWhirr. He was at sea and in more ways than one in the Indian Ocean. This leader of men lacked the wit to imagine the force and ferocity of cyclonic winds. Despite a falling barometer and other ominous portents of a typhoon that would all but sink his ship, MacWhirr kept steady to his course, occasionally murmuring, "Theres some dirty weather knocking about."
Here on the level sand
Between the sea and land,
What shall I build or write
Against the fall of night?
Tell me of runes to grave
That hold the bursting wave,
Or bastions to design
For longer date than mine.
A. E. Housman (1859-1936)