Life in control of environment?

Press, 6 September 1980, Page 17

Life in control of environment?

Gala: A New Look at Life on Earth. By J. E. Lovelock. Oxford University Press, 1980. 154 pp. $16.50.

(Reviewed by

Ralf Unger)

The Gaia hypothesis abandons the usual supposition that life adapts .to the planetary-conditions as it and they evolve their , separate ways, end instead postulates that the physical and chemical condition of the. surface of the earth, of the atmosphere, and of the oceans has been, and is, actively made fit and comfortable by the pre-, sence of life itself. It- is therefore proposed that the biosphere is a. selfregulating entity with its bwn capacity to keep healthy by controlling'the chemical and physical environment “Gaia” is Greek for the concept of Mother Earth .and the author, who in r vented the Electron Capture Detector, pursues his hypothesis through various scientific ..disciplines and readings in. inter-planetary travel.- He. has produced a book that is challenging to various of our present day functions, but complex to follow in its logic. “Life” is defined as a process found wherever there is an abundant flow of energy, characterised by a tendency to shape or form itself as it consumes,, but in doing so always excreting low grade products to the y surroundings. It can immediately be seen from this hbw the concept of natural energy can be fitted into the framework. Thus, for example, Earth’s atmosphere is seen to be manipulated on a day-to-day.? basis from the surface and that the manipulator is life itself.

By travelling into space we have had a chance for the first time to look at Earth, giving rise to a new set of questions and answers regarding the concept of the relationship between Earth and its biosphere. The continual feedback, or cybernetic system, which seeks an optimal physical ahd'chemical environment? for life on this, planet under relatively constant conditions, may be described by the term “homeostasis.”- This! is an alternative to. the pessimistic view which sees Nature as a primitive force to be subdued and conquered. It is, also an option to that equally depressing picture.. of our planet as a demented spaceship for-, ever travelling driverless and purposeless around the-inner circle of the sum For example,- there is the alleged threat posed by aerosols to the ozone layer which, if depleted, would allow a flood of lethal ultraviolet radiation from the sun to “destroy all life on Earth.” It is doubtful, says the author, that although larger animals and plants might be seriously affected, that the unicellular life would, for the most part, even notice such an event. There are elements within the Earth whichaffect the ozone layer to a much greater extent than aerosol cans are ever likely to do and a balancing action takes place between the radiation permitted arid the life that continues to stimulate it Ozone in the atmosphere at the moment continues it"-wavering, but obstinate increase in density as if it is unaware-that it is supposed'to be decreasing. Even on the gloomiest'pre-

dictions ozone depletion is a very slow process. Large quantitites of nitrous oxide and methyl chloride enter the atmosphere from biological sources and these are claimed to be potent ozone depleters. It may be that too much'ozone is as harmful as too little and -the production of nitrous oxide and methyl chloride from natural sources represents part of a giant regulatory system. Even industrial pollution has only a minute effect on the whole surface of our planet, Earth, with natural vegetation biding its time and waiting .for some unguarded moment that trill give it a chance to return and take over everything: again. Far more significant to Gaia is the problem of feeding a world population of eight thousand million without serious damage with forecasts cf doubling of our present numbers within the next few decades. With the use of DDT, as poetically warned by Rachel Carson, the stilling of birdsong has not occurred because .the accumulation was not as great as was .expected . and recovery from its toxic effects is quicker. There appear to be natural processes for its removal which were, not anticipated -when the investigation began. These remarks should give some of the flavour of this stimulating small book. It is not an attack on environmentalists, but another angle from which to view the feeble efforts of Man to make or destroy within the larger system of tensions and forces of the universe itself.