Gaian Variations libretto

Act I

Part 1



1. Introduction

Thomas: Prologue on the Moon

Viewed from the distance of the moon, the astonishing thing about the earth, catching the breath, is that it is alive. Aloft, floating free beneath the moist, gleaming membrane of bright blue sky, is the rising earth, the only exuberent thing in this part of the cosmos. If you could look long enough, you would see the swirling of the great drifts of white cloud, covering and uncovering the half-hidden masses of land. If you had been looking for a very long, geologic time, you could have seen the continents themselves in motion, drifting apart on their crustal plates, held aloft by the fire beneath. It has the organized self-contained look of a creature alive.



2. [instrumental - birth of the orchestra]



3. Lovelock: The Idea, with first Chorale

The idea that the Earth is alive is at the outer bounds of scientific credibility, and Gaia theory is as out of tune with the broader humanist world as it is with established science. [chorale:]The idea is probably as old as humankind. But its first expression as a fact of science was by James Hutton. He is rightly remembered as the father of geology, but his idea of a living Earth was forgotten, or denied.



4. Eiseley’s Drama 1

It is an old idea in western thought, that man the microcosm reproduces in miniature the events of the macrocosm. It has been contended that James Hutton, as a medical man, applied this idea to the earth, treating it as a living organism with circulation, metabolism, and other correspondances to the organic world. It has been termed Hutton’s secret.


(see diagram 2)

5. Lovelock: The Secret Aria

Just as we can hear the pulse, the blood pressure, the electrical activity of the heart, without interfering with the normal physiology of a human subject; so can we observe the circulation of the air, the oceans and the rocks. We can measure the seasonal pulsing of the carbon dioxide of the air as the plants breathe it in and the consumers breathe it out. We can follow the course of essential nutrients from the rocks to the ocean to the air and back again, and see how at each step different but interlinked systems are affected.



6. Eiseley’s Drama 2

Time and raindrops! It took enormous effort to discover the potentialities of both those forces. It took centuries before the faint trickling from cottage eaves and gutters caught the ear of some inquiring scholar. Men who could visualize readily the horrors of a universal flood were deaf to the roar of the invisible Niagra falling into the rain barrel outside their window.

Then someone found a shell embedded in rock on a mountain top; someone saw the birth of a new star in the inviolable Empyrean heavens, somone watched a little patch of soil carried by a stream into the valley. Another saw a forest buried under ancient clays and wondered. Some heretical idler observed a fish in stone. Because of these small buried events, a world would eventually die, only to be replaced by another - the world in which we now live.



Part 2



7. Lovelock: What is Gaia?

The name Gaia is not a synonymn for the biosphere. Still less is Gaia the same as the biota, which is simply the collection of all individual living organisms. Just as the shell is part of a snail, so the rocks, the air and the oceans are part of Gaia. There is no clear distinction anywhere on the Earth’s surface between living and nonliving matter. There is merely a heierarchy of intensity going from the ‘material’ environment of the rocks and the atmosphere to the living cells. At some time early in the Earth’s history before life existed, the solid earth, the atmosphere, and the oceans were still evolving by the laws of physics and chemistry alone. It was careering, downhill, to the lifeless steady state of a planet almost at equilibrium. Briefly, in its headlong flight through the ranges of chemical and physical states, it entered a stage favorable for life. At some special time in that stage, the newly formed living cells grew until their presence so affected the Earth’s environment as to halt the headlong dive towards equilibrium. At that instant the living things, the rocks, the air, and the oceans merged to form the new entity, Gaia. Just as when the sperm merges with the egg, new life was conceived. Life is a planetary-scale phenomenon. On this scale it is near immortal and has no need to reproduce.

There can be no partial occupation of a planet by living organisms. It would be as impermanent as half an animal. The presence of sufficient living organisms on a planet is needed for the regulation of the environment. Where there is incomplete occupation, the ineluctable forces of physical and chemical evolution would soon render it uninhabitable.



8. Eiseley’s Drama 3

Erosion was beginning to be faintly glimpsed as a power at work in nature, and there was persistent wonder about fossils, which were then called "formed stones." The change which was to pass over human thinking, however, began in the skies -


(see diagram 1
& diagram 5)

9. Lovelock - the Atmosphere Quartet

9a I. Infrared Signal Allegro

The concept that the earth is actively maintained and regulated by life on the surface had its origins in the search for life on mars. The messages Viking returned as radio signals to the earth returned only the chill news of life’s absence. We then looked at the earth with fresh eyes, and found many things, including the radiation from the earth of an infrared signal characteristic of the anomalous chemical composition of its atmosphere. This unceasing song of life is audible to anyone with a receiver, even from outside the solar system.


9b. II. The Chemical Cappella

The least complex and most accessible part of a planet is its atmosphere. Mars’ and Venus’ are dominated by carbon dioxide, with only small proportions of oxygen and nitrogen. More important, both have atmospheres close to the chemical equilibrium state. The Earth, by contrast, has an atmosphere dominated by nitrogen and oxygen. A mere trace of carbon dioxide is present, far below the expectation of planetary chemistry.


9c. III. Stained Glass Aria

We all take our first breath of life sustaining air and from then on take it for granted. We are confident it will be there to breathe as constant in composition as is the Sun is constant in its rising and setting. Air is invisible, almost intangible, but if you look at it from above, from space, you see it as something new, something unexpected. It is the perfect stained glass window of the world, but also it is a strange mixture of unstable, almost combustible gases. My flash of enlightenment was that to keep constant something must be regulating it and that somehow life at the surface was involved.

9d IV. The Cat’s Fur Finale

The chemical composition of the atmosphere bears no relation to the expectations of steady-state chemical equilibrium. Disequilibria on this scale suggest that the atmosphere is not merely a biological product, but more probably a biological construction: not living, but like a cat’s fur, a bird’s feathers, or the paper of a wasp’s nest, an extension of a living system designed to maintain a chosen environment.



10. Eiseley’s Drama 4

Hutton saw a bit of soil carried away by a mountain brook or a spring freshet lodge in and nourish a lower valley; he saw the wind endlessly polishing and eroding stones on the high flanks of the world. If a leaf fell he knew where it was bound, and multiplied it mentally by ten thousand leaves in ten thousand thousand autumns. For him and him alone, the water dripping from the cottagers’ eaves had become Niagaras falling through unplumbed millenia. Every particle in the world was hurrying somewhere. "Nature," he wrote simply, "lives in motion."



11. [invention 1; piano solo]



12. Lovelock: Iodine Particle Fugue

Our uncertainties about the future of our planet and the consequences of pollution stem largely from our ignorance of planetary control systems. If Gaia does indeed exist, then there are associations of species which co-operate to perform some essential regulatory functions. The thyroid gland is present in all mammals and most vertabrates. It harvests the meagre supplies of iodine from the internal bodily environment and converts them into iodine-bearing hormones which regulate our metabolism and without which we cannot live. Certain large marine algae, laminaria, may perform a similar function to the thyroid gland but on a planetary scale. These long straps of seaweed, whose habitat is the inshore waters where the sea always covers them even at the lowest tide, concentrate the element iodine from sea-water and process from their harvest a curious set of iodine-bearing substances. Prominent among them is methyl iodide. Methyl iodide produced by laminaria either escapes eventually into the atmosphere or reacts with sea-water to form a more chemically stable and even more volatile substance, methyl chloride. The methyl iodide which escapes from the sea travels through the air, but in a matter of hours, especially in sunlight, it is decomposed and sets free that life-essential element, iodine. Fortunately, iodine is also a volatile substance and remains in the air long enough to be blown across the continents. Some of it is believed to react with organic components in the air and re-form methyl iodide, but one way or another the iodine of the sea, concentrated by laminaria, is blown through the air to the land surfaces of the Earth and is absorbed by mammals like ourselves, who cannot live without it.



13. Eiseley’s Drama 5

Certainly it was not long before Hutton’s views were utterly at odds with that school known as catastrophism. In it, each cataclysm shut one geological period off almost totally from another. It was one great Biblical event multiplied by a chain of such events extending backward into the past.



14. Lovelock: The Chain of Events

The early reaction, soon after the Gaia hypothesis was introduced in the early 1970s, was ignorance in the literal sense. For the most part the Gaian idea was ignored by professional scientists. Gaia had first been seen from space and the arguments used were from thermodynamics. To me it was obvious that the Earth was alive in the sense that it was a self-organizing and self-regulating system. To Ford Doolittle, from his world of molecular biology, it was equally obvious that evolution by natural selection could never lead to "altruism" on a global scale. To many scientists Gaia was a teleological concept, one that required foresight by the biota. This was a final condemnation. Teleological explanations, in academe, are a sin against the holy spirit of scientific rationality.



15. Eiseley’s Drama 6

When the Divine Maker was retired from the earthly scene by science, leaving only secondary causes to operate nature for him, men, animals, and the celestial machine were no longer to be quite what they had been in the days of supernatural intrusion. The Microcosm would no longer repeat the Macrocosm. The celestial clocks would no longer chime in perfect order.



16. Lovelock: The Colligative Chorale

All collections of living things show properties unexpected from a knowledge of a single one of them. Homeostasis is a colligative property of life. All life forms incessantly modify the physical and chemical environment. Gaia is forever changing as life and the Earth evolve together.




[intermission 1]






Act II

Part 3


(see diagram 3)

17. Lovelock: Top Secret Instincts

The concept of Gaia is entirely linked with the concept of life. I have long thought that the answer to the question "What is life?" was deemed so important to our survival that it was classified "top secret" and kept locked up as an instinct in the automatic levels of the mind.



18. Eiseley’s Drama 7

Man, even primitive man, has tended to take life for granted. Death is the unnatural thing, the after-message of the gods, or, in the Christian world, the result of the Fall from the Garden. In the development of a scientific approach to life on this planet the recognition of death - species death, phylogenetic death - had to precede the rise of serious evolutionary thought. It may be asked, as fossils slowly became accepted as the remains of creatures once living, how men were for so long able to evade the question of extinction - the existence of death before the Garden. The problem which caused such hesitation, was how to explain the apparent irrationality and waste involved in the discovery of extinction. But a world view does not dissolve overnight. Rather, like one of Hutton’s mountain ranges, it erodes through long centuries. The hint of extinction in the geological past was like a wind out of a dark cellar. It chilled men’s souls. A vast and shadowy history loomed in the rocks.


(see diagram 9
diagram 10

diagram 13
diagram 17
diagram 18)

19. Lovelock - The Baby Bio

We know from the record of the sedimentary rocks that for the past three and a half billion years the climate has never been, even for a short period, wholly unfavorable for life. Indeed, subtle evidence from the ratio of the different forms of oxygen atoms laid down in the rocks over the course of time strongly suggest that the climate has always been much as it is now, except during glacial periods or near the beginning of life when it was somewhat warmer.

The history of the Earth’s climate is one of the more compelling arguments in favor of Gaia’s existence. Our sun, being a typical star, has evolved according to a standard and well established pattern. A consequence of this is that during the three and a half aeons of life’s existence on the Earth, the sun’s output of energy will have increased by 30 per cent. Thirty per cent less heat from the sun would imply a temperature for the Earth well below the freezing point of water. We know from the record of the rocks that no such adverse conditions existed.

Our planet may have been for a while as bare as the moon is now. Later, the pressure of the Earth’s own mass and the pent-up energy of its highly radioactive contents heated up the interior until gases and water vapour escaped to form the air and the oceans. We surmise that at the time when life began the gases from the interior were richer in hydrogen than those which now vent from volcanoes. Although we have very little direct evidence about the chemistry of the Earth when life began, we do know that the atmosphere was not oxidizing like now. It seems probable that aeons ago Mars, Venus and the Earth had similar surface compositions, rich in carbon dioxide and water and with traces of the reducing gases hydrogen, methane and ammonia. The Earth must have had a slightly reducing atmosphere and strongly reducing oceans at the time when life began. The flux of reducing materials from the Earth’s interior, like the ferrous form of iron and sulfur, were vast and kept free oxygen from appearing in the air for more than a billion years.

An important gas for the early atmosphere was carbon dioxide. Scientists now think that its presence as the dominant atmospheric gas acted as a blanket that kept our planet warm at a time when the sun was less radiant than it is now. Like the nutrients in a hen’s egg, the abundant organic chemicals from which life first evolved would have supplied the infant creature with the food needed for its early growth. Unlike the chick, however, for life there was only a limited supply of food beyond the ‘egg.’ As soon as vital key compounds grew scarce, the infant would have been faced with the choice of starving or learning to synthesize its own building blocks from the more basic raw materials of the environment, using sunlight as the driving force. As we have seen, the early environment of the first photosynthesizers, the cyanobacteria, is likely to have been a reducing one. The geological record shows that vast quantities of crustal rock containing the ferrous or more reduced form of iron were oxidized during the early stages of life. Eventually, perhaps two aeons ago, all the reducing materials of the crust were oxidized more rapidly than they were exposed geologically, and the continued activity of aerobic photosynthesizers led to the accumulation of oxygen in the air. This was probably the most critical period of all in the history of life on Earth. Oxygen gas in the air of an anaerobic world must have been the worst atmospheric pollution incident that this planet has known. The event would have led to a decline of methane gas to near its contemporary abundance, thereby removing its greenhouse effect. In this model of the early history of Gaia, the successful evolution of the photosynthesizers could have led to the first environmental crisis on Earth, and I like to think the first evidence of Gaia’s awakening. The model matches the Earth’s early history. There is no evidence of unusual temperature change during the Archean, and there was a cold glacial period 2.3 aeons ago that may have coincided with the appearance of free oxygen and the corresponding disappearance of methane, marking the end of the epoch.



20. Eiseley’s Drama 8

In the years following Hutton’s death, the slow alteration of earth’s features postulated by him and Lamarck gave way before the widespread popularity of catastrophism. But linked with it, there appeared a new and popular theory in which extinction was finally recognized by science. It was generally conceived that the lower and earlier forms of life pointed on directly to man, who had been ordained to appear since the time of the first creation. Now, in late catastrophism, taking extinction into account, whole orders of life are swept out of existence in the great march to man. From the idea that one lost link in the chain of life might cause the whole creation to vanish, man had passed, in little more than a generation, to the notion that the entire world was periodically swept clean of living things. Vertebrate paleontology seemed to illuminate, in lightning flashes, a universe that progressed in leaps amidst colossal destruction. Still, there was a pattern amidst the chaos. While strange animals arose and perished, it was observed that the great patterns of life, the divine blueprints, persisted from one age to another.



21. [invention 2; violin & piano]


(see diagram 15
& see diagram 16)

22. Lovelock Interlude: to Emily, a love song

One critic referred to my first book scathingly as a fairy story about a Greek goddess. In a way he was right. It was also a long letter to a yet unkown love.............

Emiliana huxleyii, known by her friends as Emily, is one of the more important parts of the biota. Blooms of these phytoplankton cover parts of the sea; their presence powerfully affects the environment, through their capacity to facilitate the removal of carbon dioxide from the air, and their production of dimethyl sulfide, which acts to nucleate clouds on the sea. Anything affecting the cloud cover over the seas could powerfully affect the climate of the Earth. Calculations to estimate the effect that the present natural emissions of dimethyl sulfide could have suggest that it is comparable in magnitude with that of the whole carbon dioxide greenhouse, but in opposition to it. Dimethyl sulfide [made by Emily] is also now known to be the major bearer of the element sulfur from the sea to the land. [Emiliana - Emily - Emily, my love!]



23. Eiseley’s Drama 9 & Eiseley’s Song I; The Singing Mammal

Catastrophism may be said to have died of common sense. Slowly the accumulation of geological information began to lead back toward the pathway pursued earlier by James Hutton. Sir Charles Lyell, who was born the year of Hutton’s death, reapproached the whole problem of uniformitarian geology. He, like Hutton, had an eye for the common observable workings of sunshine and water drops. He was one of the first who saw that the eyes of fossil trilobites showed light falling upon the earth many millions of years ago as it falls today. He saw local disconformities of strata, and the rise and fall of coast lines. He observed that the long course of geological change was bound to effect the life upon the planet’s surface. If species perish, somewhere there must be creation. Could there be individual point emergences as well as vanishings? He hesitated. He had reintroduced into geology the lengthier time span of Hutton, and Hutton’s devotion to purely natural forces. It was, however, difficult to see how those forces applied to the single great mystery - life. Lyell stood, actually, on the verge of Darwin’s discovery. Hutton had taken life for granted because almost nothing was known in his day of the antediluvian world of fossils. Lyell, by contrast, was confronted by a perverse, unexplainable force that crawled and changed through the strata - life. He made death natural, but it could be said that life defeated his efforts to understand it.

Eiseley’s Song I [attacca]

Into this world of the celestial machine, a ghost has come, a ghost whose step must have been as light and imperceptible as the first scurry of a mouse in Cheop’s tomb. Musing over the archean strata, one can hear it and see it in the subcellars of the mind itself, a little green in a fulminating spring, some strange objects, floundering and helpless in the ooze on the tide line, something beating, beating, like a heart until a thundering goes up through the towering strata, until no drum that ever was can produce its rhythm, until no mind can contain it, until it rises, wet and seaweed-crowned, an apparition from marsh and tide pool, gross with matter, gurggling and inarticulate, ape and man-ape, until the thunder is in oneself and is passing - to the ages beyond - to a world unknown, yet forever being born. "It is carbon," says one, as the music fades within his ear. "It is done with the amino acids," contributes another. "It rots and ebbs into the ground," growls a realist. "It began in the mud," criticizes a dreamer.

Since the first human eye saw a leaf in Devonian sandstone and a puzzled finger reached to touch it, sadness has lain over the heart of man. By this tenuous thread of living protoplasm, strectching backward into time, we are linked forever to lost beaches whose sands are long since turned to stone. The stars that caught our blind amphibian stare have shifted far, but still that naked glistening thread winds onward. Its forms are phantoms. The thread alone is real. "Nevertheless, there is a goal," we seek to console ourselves. "The thread runs to a goal." If you look closely, you can see the singing reptile in the bird.



24. Lovelock; Following the thread

If Gaia exists, the relationship between her and man, a dominant animal species, and the possibly shifting balance of power between them, are questions of obvious importance. But this is written more to stimulate. Gaia theory is for those who like to walk or simply stand and stare, to wonder about the Earth and the life it bears, and speculate about the consequences of our own presence here.

Intermezzo (25.)

~~~ "Hymn to Rosa Valado’s Dying Earth" ~~~

an instrumental movement for strings



Part 4




26. Eiseley’s Song II; In the Willow Thicket

Species died irregularly like individual men over the long and scattered waste of eons. And they must be replaced in as scattered a fashion as their deaths. Creation and its mystery could no longer safely be relegated to the past. It might now reveal itself to man at any moment in a farmer’s pasture, or a willow thicket. By the comprehension of death man was now beginning to glimpse another secret. The common day had turned marvelous. Creation - whether seen or unseen -must be even now about us in the prosaic world of the present.



27. Eiseley’s Drama 10

Now it was not really new facts that were needed so much as a new way of looking at the world from an old set of data. The individual variation which all organisms revealed, the hereditary alterations produced by the breeder’s art, the unreturning fossils in the rocks, were finally combined in the minds of Charles Darwin and Alfred Wallace with the world of competitive struggle, with that concept of adaptation and plenitude which was now seen to eternally jostle the living in and out of existence.



28. Lovelock’s Variation: Adapting Darwin

Evidence shows the earth’s crust, oceans, and air to be either directly the product of living things or else massively modified by their presence. Consider how the oxygen and nitrogen of the air come directly from plants and microorganisms, and how the chalk and limestone rocks are the shells of living things once floating in the sea. Life has not adapted to an inert world determined by the dead hand of chemistry and physics. We live in a world that has been built by our ancestors, ancient and modern, and which is continuously maintained by all things alive today. Organisms are adapting in a world whose material state is determined by the activities of their neighbors. On a planetary scale, the coupling between life and its environment is so tight that the tautologous notion of adaptation is squeezed from existence. Our interpretration of Darwin is altered.



29. [invention 3; string quartet]


(see diagram 7
diagram 8
& diagram 19)

30. Lovelock Scherzo: The Dance of Daisyworld

Picture a planet about the same size as the Earth, spinning on its axis and orbiting, at the same distance as the Earth, a star of the same mass and luminosity as the sun. This is the planet Daisyworld, so called because the principal plant species are daisies of different shades of color: some dark, some light, and some neutral colors in between. The star that warms and illuminates Daisyworld shares with our Sun the property of increasing its output of heat as it ages.

Daisyworld is simplified in the following ways. The environment is reduced to a single variable, temperature, and the biota to a single species, daisies. If too cold, below 5 degrees C, daisies will not grow; they do best at a temperature near 20 degrees. If the temperature exceeds 40, they will wilt and die. The mean temperature of the planet is a simple balance between the heat received from the star and the heat lost to the cold depths of space. Daisyworld is assumed to have a constant amount of carbon dioxide, enough for daisies to grow but not so much as to complicate the climate. Similarly, there are no clouds to mar the simplicity of the model. The mean temperature of Daisyworld is simply determined by the average shade of the color of the planet, or albedo. Albedos range from 0 to 1. The bare ground of Daisyworld is usually taken to have an albedo of .4 so that it absorbs 40 percent of the sunlight that falls upon it. Daisies range from albedo .2 - dark- to albedo .7 - light.

Imagine a time in the distant past of daisyworld. The star that warms it was less luminous, so that only in the equatorial region was the mean temperature of bare ground warm enough for growth. Here daisies would slowly germinate and flower. Let us assume that in the first crop multicolored, light and dark species were equally represented. Even before the first season’s growth was over, the dark daisies would have been favored. Their greater absorption of sunlight in the localities where they grew would have warmed them above 5 degrees. The lighter colored daisies would be at a disadvantage. Their white flowers would have faded and died because, reflecting the sunlight as they do, they would have cooled below the critical 5 degrees.

The next season would see the dark daisies off to a head start, for their seeds would be the most abundant. Soon their presence would warm not just the plants themselves, but, as they grew and spread across the ground, would increase the temperature of the soil and the air, at first locally and then regionally. With this rise in temperature, the rate of growth, the length of the warm season, and the spread of dark daisies would all exert a positive feedback and lead to the colonization of most of the planet by dark daisies. The spread of dark daisies would eventually be limited by a rise of global temperature to levels above the optimum for growth. Any further spread of dark daisies would lead to a decline in seed production. In addition, when the global temperature is high, white daisies will grow and spread in competition with the dark ones. The growth and spread of white daisies is favored then because of their natural ability to keep cool. As the star that shines on Daisyworld grows older and hotter, the proportion of dark to light daisies changes until, finally, the heat flux is so great that even the whitest daisy crop cannot keep the planet below the critical 40 degrees limit for growth. At this time flower power is not enough. The planet becomes barren again, and so hot that there is no way for daisy life to start again.

In Daisyworld, one property of the global environment, temperature, was shown to be regulated effectively, over a wide range of solar luminosity, by an imaginary planetary biota without invoking foresight or planning [ - this is a definitive rebuttal of the accusation that the Gaia hypothesis is teleological, and so far it remains unchallenged].


(see diagram 4)

31. Lovelock: The Redwood Chorale

You may find it hard to swallow the notion that anything as large and apparently inanimate as the Earth is alive. Surely, you may say, the Earth is almost wholly rock and nearly all incandescent with heat.

Let the image of a giant redwood tree enter your mind. Surely alive, yet 99 percent dead. The great tree is an ancient spire of dead wood, made of lignin and cellulose by the ancestors of the thin layer of living cells that go to constitute its bark. How like the earth, and more so when we realize that many of the atoms of the rocks far down into the magna were once part of the ancestral life from which we all have come.




[intermission 2]








Part 5



32. Lovelock: Gaian Variations [or, Divisions of the Ground]

It took the view of the earth from space to give us the personal sense of a real live planet on which the living things, the air, the oceans and the rocks all combine in one as Gaia.

As we move in towards the earth from space, first we see the atmospheric boundary that encloses Gaia; then the borders of an ecosystem such as the forests; then the skin or bark of living animals or plants; further in are the cell membranes; and finally the nucleus of the cell and its DNA. If life is defined as a self-organizing system characterized by an actively sustained low entropy, then, viewed from outside each of these boundaries, what lies within is alive.



Part 6



33. Eiseley’s Drama 11

It was not natural selection that was born in 1859, as the world believes. It was natural selection without balance. Bruckner’s "impetuous torrent," which he visualized as beating against its safe restraining dikes, is loose and rolling. The violence of Hutton’s raindrop is equaled, if not surpassed, by the violence contained in a tiny microscopic genetic particle. The world of geological prophecy has vanished. There is only this vast uneasy river of life spreading into every possible niche, dreaming its way toward every possible form. Since the beginning there have been no breaks in that river. The immaterial blueprints were an illusion generated by physical descent. The lime in our bones, the salt in our blood were not from the direct hand of the Craftsman. They were, instead, part of our heritage from an ancient and forgotten sea.


(see diagram 6
& diagram 11)

34. Lovelock: Why is the Sea Salt?

Why is the sea salt? It is often stated that the preferred internal saline medium of living things, one that is astonishingly similar over a wide range of organisms, reflects the composition of the oceans when life started. It is true that the salinity of the blood of whales, humans, mice and of most fish, whether dwelling in the ocean or in fresh water, is the same. But to my mind this is no more evidence of the salinity of the Archean ocean than are the oxygen levels now breathed by these organisms evidence of the oxygen abundance at the start of life.

Why is the sea salt? The answer that was once confidently given ran something like this: the sea became salt because rain and rivers constantly washed small amounts of salt from the land into the sea. The surface waters of the seas may evaporate, but salt is always left behind. This theory should enable us to calculate the age of the oceans. There is no difficulty estimating their total salt content at the present time. The input of salt into the sea is 540 megatons each year; the total volume of sea water is 1.2 thousand million cubic kilometers; the average salinity is 3.4 percent. Therefore the time taken to reach the present level of salinity is about 80 million years. However, this answer is manifestly out of step with all of palaeontology. It seems reasonably certain that life began in the sea and geologists have evidence of simple organisms from three and a half aeons ago. The oceans must be at least as old. And evidence shows that the salt of the sea has not changed much since oceans started and life began; not enough, in any event, to account for the difference between the present salinity of the sea and that of our blood.

We are forced by discrepencies of this kind to rethink why the sea is salt. The average sample of sea-water contains 3.4 percent inorganic salts, of which 90 percent is sodium chloride. This statement is not strictly accurate, because when salts dissolve in water they split into two separate sets of atom-sized particles with opposite charges. These particles are known as ions. One of the lesser known requirements for a living cell is that, with rare exceptions, the salinity of either its internal fluids or its external environment must never exceed for more than a few seconds a value of 6 percent. The thin film that encapsulates every living cell contains ion-pumps which selectively exchange internal for external ions according to the cell’s needs. Electrical forces ensure that the cell-membrane has the strength and flexibility for these operations. If the concentration of salt on either side of the membrane exceeds the critical level of 6 percent, the screening effect of the salt-derived ions clustered around the electrical charges is too strong. The tension is lost, the weakened membrane disintegrates, and the cell falls apart.

We can now see why living organisms, deeply dependent on the operation of electrical forces, can survive only if the salinity of the environment is held within safe limits, and particularly within the critical limit of 6 percent. In light of this knowledge, we begin to lose interest in the original question: ‘Why is the sea salt’ The more important question is: ‘Why isn’t the sea more salt?’ Catching a glimpse of Gaia, I would answer: ‘Because since life began, the salinity of the sea has reflected the presence of marine organisms’ The next question is obviously: ‘But how?’ Which brings us to the crux of the matter, for what we really need to know and think about is not how salt is added to the sea but how it is removed.


(see diagram 14)

35. Lovelock: The Fire’s Balance

A model of the evolution of oxygen and carbon dioxide regulation can be extended from the Archean to the present day. But it is unable to account for the precise regulation of oxygen observed for the past several hundred million years. It has been shown that fires cannot be started, even in dry twigs, when oxygen is below 15 percent. The probability of a forest fire being started by a lightening flash increases 70 percent for each 1 percent rise in oxygen concentration above the present level. Above 25 percent oxygen, fires are so fierce that even the damp wood of a tropical rain forest would burn in an awesome conflagration. Oxygen is 21 percent, close to the mean between these limits. It might even be that fires themselves are the regulator of oxygen.



36. Eiseley’s Drama 12: The Bone Assembly

Three years before Darwin gave to the world his theory, two German quarrymen were digging in a small cave along a gorge of the Neander. In a dark interior chamber the workmen stumbled upon some strange bones. As the deposit of clay and stones was removed, lying near the entrance of the grotto, the men first came upon a skull. Today we know that this low-browed, thick-walled vault of skull belongs to an era far more remote than anyone dreamed. When this dead man had been interred in the little cave, all the enormous triumphs of humanity, the piled wealth of our great cities, still lay tens of thousands of years in the future. These creatures were an odd and unimagined link with the past. Their skulls held brains as large or larger than our own. Bone by bone, flint by flint, man has been traced back into the night of time.

On the glacial uplands of Europe, winds had howled and dust had swirled over naked grasslands. This man had fought a battle for survival, and cold and the prowling beasts pushed south by the long inexorable advance of the ice. Now we know that these supposed brutes had laid down their dead in grief. Worked flints had been poured lovingly into their graves. It has become more clear with the passing years that the place of the human emergence lies much farther back. The nature of the original animal-man is still a matter of debate. But perhaps, there too, some bit of the same message has come down all those eons that we have, without words, from the Neanderthal: ‘We too were human, we too suffered, we too believed that the grave is not the end. We too, whose faces affright you now, knew human agony and human love.’

Man has, in scientific terms, become natural, but the nature of his "naturalness" escapes him. A curious twofold interpretation of the psyche has descended from Darwin to modern science: man the weak-bodied unarmed primate, and man the warrior - the product of ruthless, competitive forces. Perhaps the two sides of Darwin’s dark question were only an evolutionary version of man’s ancient warfare with himself - a drama as great in its hidden fashion as the story of the Garden and the Fall.


(see diagram 20
& see diagram 21)

37. Lovelock’s Hidden Drama

It is almost automatic to assume that early man was in total harmony with the rest of Gaia. Perhaps we were indeed expelled from the Garden of Eden, but Biblical teaching that the Fall was from a state of bliss, into the sorrowful world of flesh, is hard to accept in our current culture. Nowadays it is more fashionable to attribute our fall to man’s insatiable curiosity and his urge to experiment and interfere with the natural order of things. One of the few certainties about the Earth is that we have changed the atmosphere and the land more than it has changed by itself in a million years. Like it or not, however - and whatever we may do to the total system- we shall continue to be drawn, unawares, into the Gaian process of regulation.



38. Lovelock’s Declaration

In Gaia we are just another species, neither the owners nor the stewards of this planet. Our future depends much more upon a right relationship with Gaia than with the never-ending drama of human interest.



(see diagram 21)

39. Lovelock’s Last Warning

A frequent misunderstanding of my vision of Gaia is that I champion complacance, that I claim feedback will always protect the environment from any serious harm that humans might do. Gaia is no doting mother tolerant of misdemeanors. She is stern and tough, always keeping the world warm and comfortable for those who obey the rules, but ruthless in her destruction of those who transgress. Her unconscious goal is a planet fit for life. If humans stand in the way of this, we shall be eliminated with as little pity as would be shown by the micro-brain of a nuclear missile in full flight to its target.



40. Fact Finale



The Earth is alive!