James Lovelock, Gaia: A New Look at Life on Earth, New York: Oxford University PRess, 1979, pp. vvi-12.
We all know of “Mother Earth” – even the Greeks called her Gaia. She, as a concept, has been the basis of a belief that lasts the length of recorded history. Recently, as a result of the accumulation of evidence about the natual environment and the growth of the science of ecology, there have been speculations that the biosphere may be more that just the complete range of all living things within their natal habitat of soil, sea, and air.
The hypothesis of Gaia is that:
The Earth’s living matter, air, oceans, and land surface form a complex system which can be seen a a single organism and which has the capacity to keep our planet a fit place for life.
James Lovelock takes us through his personal account of a journey through space and time in search of evidence that substantiates this model of the earth. His quest ranged through many territories of different scientific disciplines – from astronomy to zoology. Each territory is “jealously guarded” by their Professors, and within each territory is different arcane language to be learnt.
For a chemist to travel through distant disciplines, he needs something to barter: a piece of hardware of a technique. Luckily for Lovelock, he was able to work with A.J.P. Martin in developing the important chemical analytical technique of gas chromatography. Lovelock added embellishments to extend the range of Martin’s invention: the device called the electron capture detector. Notable for exquisite sensitivity in detecting traces of certain chemical substances, it first made possible the discovery that pesticide residues were present in all creatures of Earth: from Penguins in Antarctica to nursing mothers in the U.S.. It has also detected minute but significant quantities of other toxic chemicals in places where they ought not to be: PAN (peroxyacetyl nitrate), a toxin in L.A. smog, PCBs (polychlorobiphenyls), in the remote natal environment, and chlorofluorocarbons and nitrous oxide – substances which are thought to deplete the strength of ozone in the stratosphere.
In Lovelocks quest for Gaia, the electron capture detectors was a valued trade good, and helped him to literally travel around the Earth. But, in his interdisciplinary nature, he also witnessed plenty of turmoil in the life sciences, especially in areas where science has been drawn into the processes of power politics.
When making us aware of the dangers of the mass application of toxic chemicals (pesticides and DDT), Rachel Carson presented her arguments as an advocate rather than that of a scientist: selecting evidence to prove her case. The chemical industry responded in the same way. And this may be a good way to achieve justice for the benefit of the community at large, and in her instance was perhaps scientifically excusable, but it has established a pattern. Science concerning the environment is presented as if in a court-room or public inquiry – not necessarily with scientific truth as the goal. Unfortunately, on environmental matters the scientific community seems to have been divided into collectivized warring groups.
Truth is said to be the first casualty of war. It is also weakened by being used selectively in evidence to prove a case in law.
Lovelocks hypothesis, often simply using the term Gaia as a shorthand, is: the biosphere is a self-regulating entity with the capacity to keep our planet healthy by controlling the chemical and physical environment. He often finds it difficult to avoid talking of Gaia as if she were known to be sentient – like men of the sea, speaking of their vessel, constructed of pieces of wood and metal, giving her the appellation “she” by those who sail in her.
Lovelock begins his first chapter with mentioning the Viking spacecraft, their encircling the planet Mars, with a mission to search for life, or evidence of life, as he writing his book. In the same way his book is a search for life: for the largest living creature on Earth.
“If Gaia does exist, then we may find ourselves and all other living things to be parts and partners of a vast being who in her entirety has the power to maintain our planet as a fit and comfortable habitat for life.”
In 1961, Lovelock was asked by NASA to help in their search for life on Mars, specifically to devisee ways and means of detecting life on Mars and other planets. At that time, he describes that their experiments were based on the assumption that life on Mars would be much the same as life on Earth, i.e. looking at soil for proteins and amino-acids.
A year later, eureka struck his mind, “How can we be sure that the Martian way of life, if any will reveal itself to tests based on Earth’s life style?” and “What is life, and how should it be recognized?” Some of his sanguine colleagues mistook his skepticism for cynicism, asking what he’d do instead, and the only answer he could give was, “I’d look for an entropy reduction.”
Entropy, a confused word to be sure, considering its a synonym for disorder, is a measure of the rate of dissipation of a system’s thermal energy.
Lovelocks idea of looking for a reduction or reversal of entropy as a sign of life was implanted in his head even though it was rejected as a tentative suggestion. After leaving the laboratories, he spent time thinking and reading about the character of life and how one might recognize it anywhere. Data galore had been accumulated on every conceivable aspect of living species, physicists looked at the heat and light that life created, chemists talked about what it was made out of, and engineers said the supporting wheels were too small and in the wrong place for it to move smoothly, — but nowhere was a comprehensive definition of life as a physical process on which one could base the design of life-detection experiments, very little was written, indeed almost ignored, about the nature of life itself.
The division of science into separate disciplines has left each member thinking the other has done the job.
Our recognition of living things, both animal and vegetable, is instant and automatic, and our fellow-creatures in the animal world appear to have the same facility. This powerful and effective but unconscious process of recognition no doubt originally evolved as a survival factor. Anything living may be edible, lethal, friendly, aggressive, or a potential mate, all question of prime significance for our welfare and continued existence.
This ability has rendered us unable to consciously define life.
Definitions by physicists have been attempted:
“Life is a member of the class of phenomena which are open or continuous systems able to decrease their internal entropy at the expense of substances or free energy taken in from the environment and subsequently rejected in a degraded form.”
I have difficulty grasping this too, but also far too general to apply to the specific detection of life. Essentially, there is abundant flow of energy and it is shaped as its consumed, and it excretes low-grade products to its surroundings. But this definition applies to a stream, or hurricanes, or refrigerators.
For life, there is a boundary, between where the flow of energy is put to work and entropy is consequently reduced, and the surrounding environment which receives the discarded waste products. A flux of energy above some minimal value in order to get going and keep going is what’s being suggested. Turbulent eddies in gasses and liquids can only form if the rate of flow was above some critical value in relation to local conditions. For example:
If the sun’s surface temperature were 500 degrees instead of 5000 and the Earth were correspondingly closer, so that we received the same amount of warmth, there would be little difference in climate, but life would never had got going.
Life needs energy potent enough to sever chemical bonds; mere warmth is not enough.
Looking for a universal experiment on entropy reduction seemed to be somewhat unpromising at the time, but assuming that life on any planet would be bound to use fluid media – oceans, atmosphere, or both – as conveyor belts for raw materials and waste products, Lovelock figured that some of the activities associated with concentrated entropy reduction within a living system might spill over into the conveyor belt-regions and alter their composition. Therefore, atmosphere must be distinct on a life-bearing planet compared to a dead planet.
In looking at the Earth’s atmosphere with Dian Hitchcock of Jet Propulsion Labratories, their results convinced them that the only feasible explanation of the Earth’s highly improbably atmosphere was that it was being manipulated on a day-to-day basis from the surface, and that the manipulator was life itself. Here’s why:
In sunlight, methane and oxygen react chemically to give carbon dioxide and water vapour; to sustain the amount of methane in the air due to losses in the reaction requires 1000 million tons of it be introduced yearly. The simultaneous presence of methane and oxygen in the atmosphere at Earth’s extraordinary constant levels was improbably on an biological basis by at least 100 order of magnitude. Even nitrogen in a gaseous form is out of place – with Earth’s abundant and neutral oceans, nitrogen should be found in the chemically stable form of the nitrate ion dissolved in the sea.
Essentially, atmosphere is a dynamic extension of the biosphere itself.
Mars would easily fail this test – unwelcome news to people searching for life on it. Worse yet, the government cut funding in 1965.
Luckily for Lovelock, with the lack of a space program, Shell Research Limited invited him to consider possible global consequences of air pollution from such causes as the ever-increasing rate of combustion of fossil fuels. With his knowledge of the atmosphere as an extension of the biosphere, Lovelock figured that any attempt to understand the consequences of air pollution would be incomplete and probably ineffectual if the possibility of a response or an adaptation by the biosphere was overlooked.
In this new environment, Lovelock focus was solely on the Earth, and the result of this was the development of his hypothesis regarding that the entire range of living matter on Earth, form whales to viruses, and from oaks to algae, could be regarded as constituting a single living entity, capable of manipulating the Earth’s atmosphere to suit its overall needs and endowed with faculties and powers far beyond those of its constituent parts.
In 1967, his hypothesis was making strides because in his research of the first 3500 million years of earth Earth’s climate has changed very little – yet the output heat of the sun, the surface properties of the earth, and the composition of the atmosphere have varied greatly over the same period. The previous mentioned presence of methane, nitrous oxide, and even nitrogen in our present oxidizing atmosphere is a violation of the rules of chemistry to be measured in tens of orders of magnitude.
These things, on such a scale, suggest:
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 wasps’s nest, an extension of a living system designed to maintain a chosen environment.
In this, an albeit hypothetical, planet-sized entity was born. In giving it a name, one of Lovelocks fellow villagers, William Golding, suggest Gaia, after the Greek Earth goddess also known as Ge. Lovelock was rather happy with his fellow’s suggestion, as Lovelock was thinking of creating an acronym for his Biocybernetic Universal System Tendency/Homeostasis.
This proposition, when Lovelock talks with country folk (since scientists are often confined to urban living), they seemed puzzled that such a formal proposition needs to be created – because of how obvious the Gaia hypothesis is, – for them it is true and always has been.
Lovelocks admits that his first presentation about the origins of life on Earth, in 1969 at Princeton, may have been poorly presented, because it only appealed to two audience members – a Swedish chemist named Lars Gunnar Sillen and Lynn Margulis of Boston University. Lynn went about editing various contributions, and her insight as a life scientist added substance to Gaia.
Gaia has now (1979) been defined as:
A complex entity involving the Earth’s biosphere, atmosphere, oceans, and soil; the totality constituting a feedback or cybernetic system which seeks an optimal physical and chemical environment for life on this planet. The maintenance of relatively constant condition by active control may be conveniently describe by the term ‘homeostasis’.
She, as a hypothesis has proved her theoretical value, giving rise to experimental questions and answers which were profitable exercises in themselves, i.e. the atmosphere as a conveyor belt for raw materials to and from the biosphere (finding that iodine and sulphur are conveyed from the oceans to the air to land surfaces).
If Gaia exists, our relationship to her, as a dominant animal species in her living system, and the possibly shifting balance of power between them, are questions of obvious importance.
The Gaia hypothesis is for those who like to walk or simply stand and start, to wonder about the Earth and the life it bears, and to speculate about the consequences of our own presence here. It is an alternative to that pessimistic view which sees nature as a primitive force to be subdued and conquered. It is also an alternative to that equally depressing picture of our planet as a demented spaceship, forever travelling, driverless and purposeless, around an inner cycle of the sun.