William H. Calvin, "To Make Sure that Things Go On," Whole Earth Review (1998). See also
 Copyright 1998 by William H. Calvin

Webbed Reprint Collection

This 'tree' is really a pyramidal neuron of cerebral cortex.  The axon exiting at bottom goes long distances, eventually splitting up into 10,000 small branchlets to make synapses with other brain cells.
William H. Calvin

University of Washington
Seattle WA 98195-1800 USA

To Make Sure that Things Go On


William H. Calvin


The Red Queen told Alice that, in Wonderland, you had to run, just in order to stay in the same place. This treadmill seems to have shifted gears in the three decades since the WEC, making versatility and foresight even more important. Extrapolate another three decades ahead, to 2030, and the gears may have shifted yet again.

The big problem with speed is that reaction time doesn't increase to match; indeed, it doesn't speed up much at all, except via foresight. When things speed up, you don't have time to simply feel your way into the new situation and do feedback corrections. So anticipation becomes far more important: you now need elaborate tentative plans, compared to when the pace of change was slower and gentler, just to be able to choose the right path as the fog briefly clears. That means you need a spread of plans, an ability to imagine various contingencies.

Foresight is part of a suite of "higher intellectual functions" (including structured language, planning ahead, multistage logical inference, a fondness for games with arbitrary rules, and music) that evolved sometime in the last five million years, since we last shared an ancestor with the chimpanzees and bonobos. It made ethics possible but also warfare (the big difference between raiding and warfare is stockpiling supplies). Foresight may enable us to head off the consequences of climate change, both that caused by industrialization and that which is "natural" but threatening to civilization.

One of the big scientific surprises has been the recent realization that climate change sometimes speeds up. We now know that our ancestors suffered from a series of whiplash climate changes over the last million years or so, ones so abrupt that, within a single generation's lifetime, it was a whole new ball game, worldwide. Imagine daytime temperatures becoming more like nighttime temperatures, even in the tropics. These abrupt coolings happen, not because the sun is flickering like an old fluorescent light tube, but because ocean currents rearrange themselves so that the Gulf Stream doesn't warm Europe and, after a massive wave of forest fires, Europe reverts to being more Canadian in climate. Europe's agriculture would no longer be able to feed 23 times as many people as Canada's, and the rest of the world isn't going to be much better off, as such abrupt coolings affect most of the inhabited portions of the globe. It takes little imagination to imagine a series of wars over dwindling resources as the human population crashes and our civilization disintegrates.

Though it's been 8,200 years since the last abrupt cooling, they usually happen every several thousand years, each lasting for centuries before an equally abrupt rewarming. Some have been associated with instabilities in the ice sheets that covered Canada and Scandinavia. But it is clear that they can happen without them, even in situations like today's; indeed, our gradual global warming could trigger an abrupt cooling in several different ways. Imagine taking a shower where the water is gradually warming up but then someone starts the laundry and the shower abruptly turns cold. They don't balance out.

But a little foresight may well be able to prevent the earth's abrupt coolings, "natural" though they have been. While combating global warming is obviously high on the agenda, the physical principles involved in the abrupt rearrangements are so simple that one can imagine heading off failures with a technological booster for the giant whirlpools in the Labrador and Greenland Seas that flush cold water -- that has already given up its heat to Canadian air bound for Europe -- from the surface to the ocean depth, thus making way for more warm water to flow north. When enough of these whirlpools fail, the climate abruptly cools. Waiting until it starts to happen will be too late. The failure has typically occurred in just a few years. So clearly it's a matter of heading it off, not handling it on the fly.

But can society move quickly enough, given its usual slow reaction times when building an international political consensus is involved? Foresight isn't enough. You also need the initiative to make preemptive moves to head off some of the developments that foresight warns you about. An abrupt cooling won't be the end of humanity, but it would kill billions and destroy much of what we call civilization. To head off such catastrophic backsliding will require some preventive climate medicine.

For more, see my cover story, "The Great Climate Flip-flop," for the January 1998 issue of The Atlantic Monthly, here's the link to the full text and supplementary illustrations. The climate page provides a link-filled bibliography for the article.
And if you wonder why a neurophysiologist is writing about climate, see "Climate Instability and Hominid Brain Evolution," the after-dinner talk for the American Geophysical Union's rapid climate change conference or the longer UCLA geophysics talk. || Home Page || Calvin publication list || The Bookshelf || December 1998