The Future of Everything: The Science of Prediction
Page 31
One feature of such feedback loops is that they combine living and non-living components; another is that they make the climate extremely hard to model. No perturbation has a straightforward, linear effect; the response is always crooked. The regulatory systems that Lovelock and Margulis saw as a sign of life are also a sign of unpredictability when viewed by a mathematical modeller. The multiple non-linear feedback loops create sensitivity to errors in parameterization (see figure A.5 in Appendix III, page 359). A corollary to the Gaia hypothesis could state that the robustness of the earth system is inversely related to our ability to predict its future.
IS THE EARTH ALIVE?
Does it make sense to view the world as a living organism? One can argue that the planet is only a physical system with biological components; it has no mind, soul, free will, or DNA, so it can’t be alive. But on the other hand, plants don’t have minds, animals aren’t supposed to have souls, not everyone believes we have free will, and the earth has plenty of the rather inert substance known as DNA, including our own. There are many definitions of what constitutes life, and some would include the earth system.
One useful definition, proposed by the Chilean neuroscientists Humberto Maturana and Francisco Varela in 1987, states that a being is alive if it is autopoietic, or self-making— it produces the components that define it as a unit. What is important in this definition is not so much the material structure of life but the process, organization, and relationships of the components. For something to be alive by this definition, there is no requirement that it grow or reproduce or pass on DNA.
Other definitions assume that organisms reproduce and don’t recycle their own waste, so the earth system would not be alive. Perhaps the earth can be viewed as the opposite end of the spectrum from viruses: the latter cannot reproduce except through a host body; the earth is a host body that cannot reproduce (except perhaps through colonization). You can argue about their status as living beings, but to make predictions you have to take them both into account.
TELLING STORIES
The idea that the earth is a kind of super-organism is a very old one. As Leonardo da Vinci wrote, “By the ancients man has been called the world in miniature; and certainly this name is well bestowed, because, inasmuch as man is composed of earth, water, air and fire, his body resembles that of the earth; and as man has in him bones the supports and frameworks of his flesh, the world has its rocks the supports of the earth; as man has in him a pool of blood in which the lungs rise and fall in breathing, so the body of the earth has its ocean tide which likewise rises and falls every six hours, as if the world breathed; as in that pool of blood veins have their origin, which ramify all over the human body, so likewise the ocean sea fills the body of the earth with infinite springs of water.”32 This ancient idea gained special resonance in December 1968, with Apollo 8: that space mission allowed the earth to be viewed for the first time as a complete entity from outer space, so obviously alive in comparison with its barren neighbours, the moon and the other planets.
While Gaia theory is now well established in ecological science, and has helped spawn interdisciplinary fields such as earth system science (a kind of planetary-scale systems biology), it has sometimes been seen as bad or even “dangerous” science.33 Part of the reason may be its overt use of metaphor: we can’t prove objectively that the earth is alive; it is just a useful way of seeing things. As Lovelock wrote, metaphor is seen by scientists “as a pejorative, something inexact and therefore unscientific.”34 Aristotle said that “metaphor is a poetic device, but it does not advance our knowledge of nature.” Scientists like to chastise the media for caring only about catchy stories (at least, those the scientists don’t agree with). But models, in the end, are always stories, metaphors for the real world. They explain a sequence of events; they are products of the mind. The only way to avoid metaphor is to limit oneself to the pure forms of mathematical abstraction.
Science is therefore charged through with metaphor and mythology. The clockwork universe is a metaphor, and so are the butterfly effect, the selfish gene, and the efficient market. Compare, for example, the latter’s deification of the marketplace, with its ability to look far into the future to calculate value,35 with the psychologist James Hillman’s definition of the “archetypal premise in Apollo” as “detachment, dispassion, exclusive masculinity, clarity, formal beauty, farsighted aim and elitism.”36 Perhaps the efficient market hypothesis should be renamed the Apollo hypothesis. Most of the early opposition to Gaia theory came from proponents of the selfish gene theory, which managed to ascribe Apollonic properties to a section of chemical code. The butterfly effect allows all short-term error to be ascribed to chaos, leaving the GCMs untouched as the paragons of reason and far-sighted accuracy. Like the clockwork universe, these catchy metaphors all enforce a vision of the world as a rational, computable machine; they emphasize one side of the story. They encourage a kind of resignation in the face of determinism, as if we live in a world without choices: we are the victims of the initial condition/our genes/the market.37 The danger occurs when practitioners adopt these stories unconsciously and are unaware of their subtext.
The real issue, then, is not so much that Gaia is a metaphor, but that it is the wrong kind of metaphor. The science writer Margaret Wertheim compares the Pythagorean philosophy to a mythological Earth Mother/Sky Father polarity: “In seeking to free the immaterial psyche from the material body, the Pythagoreans were seeking to escape from the realm of the Earth Mother (in their mathematical mythology, this being represented by the number 2), and to ascend into the realm of the Sky Father (represented by the number 1).”38 From this point of view, Gaia theory will only hinder union with the divine harmony. Climate modellers probably don’t think about their jobs in quite those terms, but stories, myths, and metaphors can be as powerful and enduring as mathematical theorems. Like any mental model, they affect what we allow ourselves to see and the problems we attempt to solve.39
If the earth is more like a self-regulating organism than a piece of rock floating through space, then that is important information that has implications for our future.40 The questions we ask, and the kind of predictions we make, must change completely. The biosphere has evolved in a way that makes it hard to predict.41 That mix of gases that has been in the atmosphere since pre-industrial times isn’t there by accident; it’s part of a biological system, and that affects what will happen if we perturb it. And as environmentalists have often pointed out, our species may resemble nothing so much as a bad infection or a cancer.42. The main distinction between diseased and healthy states is a degree of excess, and our population has expanded until it has taken over much of the planet, with its impact on the environment multiplied many times by technology. We have commandeered natural systems, turning forests and rivers to our own use the way a tumour takes over blood supplies. Our economy’s toxic waste is poisoning the planet and upsetting the very regulatory networks that sustain its homeostasis. Our growth is out of control.
When any organism is threatened, it fights back. Robustness does not imply passive tolerance. Our bodies combat infection by raising the temperature, and global warming might also turn into something akin to a fever. Epidemics might similarly be seen as an antibody-like defence mechanism designed to keep us in check. As Lovelock warned, “We are at war with the Earth itself.”43 Viewed in this way, climatological, biological, and economic prediction must be seen as three aspects of the same thing. This explains why it’s so difficult to make long-term predictions of our future weather, health, and wealth: they all depend on the reaction of a robust, living planet under serious assault. This isn’t a calculation; it’s a medical crisis.
THE CASSANDRA COMPLEX
Of course, the idea that mankind is a disease on the planet is just another story. We are always reassessing our role: we used to be the apple of our creator’s eye, then we were another ape, and now we’re a disease. It is also unnecessarily fatalistic: we have choices and can control
our future. Our nature is not fixed, and disaster is not in our genes. However, if we accept that our actions are affecting key regulatory networks in the earth system, then any prognostication about the future becomes—metaphorically—like a prognosis for a patient. Medics can cover the earth with instruments and stick thermometers in every orifice and monitor each subtle symptom as it appears, but it’s hard to work out from any of these what the future holds. The normal procedure is to check medical history to identify the disease and discover its usual course; but in this case, it’s a new condition. The earth is like the first victim to stumble into a hospital emergency room. We’ve never seen Homo sapiens on this scale before. How to respond? An overly technical doctor might want to order up new scans using the latest equipment; a penny-pinching hospital administrator might say it’s all in the patient’s mind.
The current debate about global warming—between scientists who believe that global warming is an important issue and “skeptics” who don’t want to make large economic sacrifices for a problem that might not exist—resembles the argument between the technician and the administrator squabbling in the E.R. corridor. The technician has the scientific expertise and the support of most of the staff, but he is still not winning. The administrator has all the good lines, his arguments are well organized, and he’s louder. It’s an entertaining debate, and the other staff members gather round to watch. In the room behind the door, though, the patient is feeling worse—there are complications.
As is often the case in debates between people holding two extreme positions, they are both right, and they are both wrong. The technician is right to say that he believes the planet’s life systems are under threat; he is wrong to believe he can predict the outcome using technology. The administrator is right to insist that the technician’s analyses have been inaccurate in the past and are not a reliable guide to the future; he is wrong to insist on absolute proof when it is clearly impossible. They both view the patient as an object, either medical or economic.
Most people, including most politicians, are neither climate scientists nor global-warming skeptics; yet we in the industrialized world still tend to see the world in objective terms, as something to be manipulated and controlled, slave to the laws of cause and effect. This is the shadow side of our great inheritance from two millennia of science. Those predictive models of the world not only looked into the future but, in many respects, helped define it. By turning the world into an object that we can control, however, we also deny it life. And by closing off our emotional involvement with nature, we become unable to take the necessary decisions to protect it. We might be willing to buy the environmental argument intellectually, and it does seem to be getting warmer out. But as any good consumer knows, decisions are driven less by logic than by feeling. There is an intense drama going on (Who’s Afraid of the Planet Earth?), but we are looking for the light switch. We tend to get more emotional about the killing of baby seals in the Canadian North than the melting of the Canadian North; more worked up about second-hand smoke from cigarettes than that from the exhaust pipes of cars; more worried about risk factors for disease than the health of the planet. A Gallup poll in April 2006, for example, concluded that Americans are “still not highly concerned about global warming,” with no increase since the question was first surveyed in 1989, even though more agree that it is happening.44
The failure of our forecasting models, and the ancient dream to mathematically predict and control the future, grows out of this confusion between objects and living things. The authors of the Club of Rome’s World3 program, for example, say that formulating their ensemble predictions for the planet’s future is like throwing a ball up into the air. “To predict exactly how high the ball will rise or precisely where and when it will hit the ground, you would need precise information. . . . Therefore we put into World3 the kinds of information one uses to understand the generic behaviour modes of thrown balls, not the kinds of information one would need to describe the exact trajectory of one particular throw of one specific ball.”45 But the world is not an inert ball, and there is no generic response. Perhaps that is why, like Cassandra, such models so often fail to convince or to move.
Lack of predictability is a deep property of life. Any organism that is too predictable in its behaviour will die. And in an unpredictable environment, the ability to act creatively, while maintaining a kind of dynamic internal order, is a prerequisite. The balance of positive and negative feedback loops, when combined with the computational irreducibility of life processes, makes the behaviour of complex life forms impossible to accurately model. The problem is not that such organisms are erratic, but that they combine creativity with control. House plants are quite stable (they tend to stay in their pots and don’t suddenly walk off to join the forest), but it would still be impossible to predict the exact effect of moving a single plant from a shaded spot to a warm greenhouse, based only on a detailed understanding of its biochemistry. If we can’t do it for a plant, we can’t do it for a planet. Life, it seems, evolves towards rich, complex structures, which defy simplistic analysis.
Acknowledging the liveliness of the earth’s response changes the questions we ask. While we once wanted to know when our needs would be met, we now ask, Is this working out? Are we doing our part? Are we close to crossing a line? And how do we feel about that? To answer these questions, we need better metaphors, better stories.46 Like an overly formulaic Hollywood film, our current oracles are a bit corny and a bit fake, and they act mainly to distract us. To quote the Buddhist philosopher D. T. Suzuki, speaking on the subject of Zen and archery, “The arrow is off the string but does not fly straight to the target, nor does the target stand where it is. Calculation which is miscalculation sets in. The whole business of archery goes the wrong way. The archer’s confused mind betrays itself in every direction and every field of activity.”47 The archer stands square: he shoots straight, but still he misses.
9 CONSULTING THE CRYSTAL BALL
OUR WORLD IN 2100
But what have been thy answers, what but dark
Ambiguous, and with double sense deluding,
Which they who asked have seldom understood . . .
No more shalt thou by oracling abuse
The Gentiles; henceforth oracles are ceased,
And thou no more with pomp and sacrifice
Shalt be enquired at Delphos or elsewhere,
At least in vain, for they shall find thee mute.
—John Milton, Paradise Regained
Let now the astrologers, the star-gazers, the monthly
prognosticators, stand up and save thee from these things that
shall come upon thee.
—Isaiah, 47:13
FORECAST 2100
So now that we have all those theoretical points and disclaimers out of the way, we can ask how things will really look in the year 2100. While researching this book, I came across a variety of ideas, scenarios, predictions, and concerns. Most are based on the output of GCMs, coupled in some cases with models of physical, biological or economic systems. Others are speculations based on what appear to be credible scenarios. The most plausible are listed below.
The average global temperature will rise by about five degrees(C or F).
Droughts in places such as Spain, Australia, New Zealand, the Middle East, and parts of the United States will make it difficult to grow traditional crops.
Wheat yields will improve in Canada and Russia.
Sea levels will rise by a metre or more.
Summer monsoons in Asia will be more variable, with increased risks of floods or droughts.
Three million cubic kilometres of ice in the Greenland ice sheet will begin a long and unstoppable melting process.1
The West Antarctic ice sheet will also begin to melt.2
Glaciers worldwide will continue to recede.
The Arctic will have ice–free summers, impacting on ice–living animals, birds, and northern indigenous peoples.3
&nb
sp; Much of the tundra in northern countries will disappear,releasing its stores of carbon.
A combination of fires and pest outbreaks will severely damage boreal forests in China and other countries.4
Huge dust storms in the Gobi and Sahara deserts will cause respiratory problems worldwide.5
Local warming and rainfall reduction will cause parts of the Amazonian rainforest to collapse and die, releasing their stores of carbon.
Wetlands such as South America’s Pantanal will dry out, impacting species such as migratory birds.
Storms and hurricanes will dramatically intensify.6
Areas including France, Germany, and the northwest United States will experience increased heat waves, like the one that hit Paris in the summer of 2003. 7
Coastal erosion will displace hundreds of millions of people, destroy prime farmland, flood entire island nations, and result in huge costs for cities such as Alexandria, Amsterdam, Manila, Calcutta, and London.
The thermohaline ocean circulation will slow or stop, causing the U.K. winter to go Canadian.8
Warmer oceans will result in quasi–permanent El Niňo conditions.
Exhausted fisheries will not recover.9