In this timeless work that remains to encourage its many readers, the author James Lovelock sets further his thought that life on earth operates as a single organism. This book is created for non-scientists; Gaia is a journey through time and space in hunt of evidence with which to support a new and completely different model of our planet. In comparison to conventional belief that living matter is inactive in the face of threats to its existence, the book deals with the hypothesis that the earth’s living matter ocean, air and land surfaces forms a compound system that has the capability to maintain the Earth a fit position for life. Since Gaia was first published, many of the authors’ calculations have take place and his theory has turn out to be a strongly disputed topic in scientific circles. In a new Preface to this reissued title, he delineates his present state of the debate.
The Gaia hypothesis is an ecological hypothesis that proposes that living and nonliving parts of the earth are viewed as a complex interacting system that can be thought of as a single organism. Named after the Greek earth Goddess, this hypothesis postulates that all living things have a regulatory effect on the Earth’s environment that promotes life overall.
Lovelock defined Gaia 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.
His preliminary theory was that the biomass modifies the conditions on the planet to make conditions on the planet more hospitable, which means that the Gaia Hypothesis suitably described this so-called hospitality as a full homeostasis. Lovelock’s preliminary theory, accused of being teleological by his commentators, was that the atmosphere is held in reserve in homeostasis by and for the biosphere.
The author stated that life on Earth provides a cybernetic, homeostatic feedback system operated involuntarily and automatically by the biota, heading to a wide-ranging stabilization of global temperature and chemical composition.
With his preliminary hypothesis, Lovelock maintained the existence of a global control system of surface temperature, ocean salinity and atmosphere composition. His arguments were:
“The global surface temperature of the Earth has remained constant, despite an increase in the energy provided by the Sun.”
“Atmospheric composition remains constant, even though it should be unstable.”
“Ocean salinity is constant.”
In view of the fact that life begun on Earth, the energy supplied by the Sun has increased, nevertheless, the surface temperature of the planet has continued to be surprisingly constant when measured on a global scale. Moreover, he claimed, the atmospheric composition of the Earth is constant. The Earth’s atmosphere currently consists of 79% nitrogen, 20.7% oxygen and 0.03% carbon dioxide. Oxygen is the second most reactive element after fluorine, and should combine with gases and minerals of the Earth’s atmosphere and crust. Indications of methane, amounting to 100,000 tones produced per annum, should not exist, as methane is flammable in an oxygen atmosphere. This composition should be changeable, and its stability can only have been preserved with elimination or production by living organisms.
Ocean salinity has been constant at about 3.4% for a very long time, as stated by the author. It is very significant because salinity stability as most cells require a rather constant salinity and do not normally tolerate values above 5%. Ocean salinity constancy was a long-standing mystery, because river salts should have moved up the ocean salinity much higher than observed. Lately it was recommended that salinity may also be clearly influenced by seawater circulation by means of hot basaltic rocks, and rising as hot water utters on ocean spreading ridges. Conversely, the constitution of sea water is distant from equilibrium, and it is difficult to describe this fact without the influence of organic processes.
The only considerable natural source of atmospheric carbon dioxide (CO2) is volcanic activity, while the only important removal is by way of the precipitation of carbonate rocks. In water, carbon dioxide is dissolved as a “carbonic acid,” which possibly shared with dissolved calcium to materialize solid calcium carbonate or the so called limestone. Both precipitation and solution are influenced by the bacteria and plant roots in soils, where they develop gaseous circulation, or in coral reefs, where calcium carbonate is banked as a solid on the sea floor. Calcium carbonate can also be cleaned from continents to the sea where it is used by living organisms to produce carbonaceous tests and shells. When dead, the living organisms’ shells go down to the bed of the oceans where they generate deposits of chalk and limestone. Portions of the organisms with carboneous shells are the coccolithophores or algae, which also take place to partake in the formation of clouds. When they die, they release a sulfurous gas which operates as particles on which water vapor condenses to make clouds.
Lovelock sees this as one of the complex processes that maintain conditions suitable for life. The volcanoes produce carbon dioxide in the atmosphere, carbon dioxide participates in rock weathering as carbonic acid, itself accelerated by temperature and soil life, the dissolved carbon dioxide is then used by the algae and released on the ocean floor. Carbon dioxide excess can be compensated by an increase of coccolithophoride life, increasing the amount of carbon dioxide locked in the ocean floor. Coccolithophorides increase the cloud cover, hence control the surface temperature, help cool the whole planet and favor precipitations which are necessary for terrestrial plants. For Lovelock, coccolithophorides are one stage in a regulatory feedback loop.
In many ways Lovelock has not helped himself with this book as it is rather unfocused in its approach. It is clearly a popular science book aimed at the general reader rather than the academic but he tends to over egg both the science bits and the everyman explanatory parts. Notwithstanding being a somewhat short book, it does have the hint of stuffing about it. His assessment of a control system to a thermostatic electric oven runs to several pages when his point had been made in the first paragraph. Similarly his scientific analysis is cyclical or repetitive and the same analysis is repeated several times over.
Cybernetics, in terms of Gaia theory, refers to the customary study of controlled feedback systems, whereby a closed system has the capability to sustain an equilibrium state in the face of peripheral influences. This complex sounding idea is in fact quite simple or straightforward to comprehend if we use ourselves as an example. Humans are a tremendous illustration of a cybernetic system, it can be said that human’s equilibrium state is standing upright at an internal temperature of 37 degrees. As a cybernetic system, humans can adjust the posture to keep up that upright state even on a rocking ship, also if humans’ environmental temperature transforms human can take steps to maintain the internal temperature by shivering or sweating and so on. What Lovelock is suggesting in this book is that the Earth functions in the same way and that it will take steps to preserve its equilibrium state in the face of outside influences. This is a surprising theory in that it takes off in the face of most modern scientific contemplation in that it is entirely holistic when science for the past couple of centuries has been particularly reductionist.
Holistic is something of a buzzword at times, particularly when used by Governments or in business, but in essence it means to view the whole of something and the inter-dependence of its parts rather than a specific analysis of those constituent parts. Reductionism is the polar converse in that it brings forward the study of ever slighter parts with the purpose of then building up those parts into a bigger understanding of the whole. Reductionism has been the foundation for the majority of all study into the natural sciences for the past 400 years, whereas holism is more naturally at home in the social sciences.
By getting a completely holistic position Lovelock, has placed himself firmly at odds with the wider scientific community. Lovelock’s point of view is originated on his work with NASA during the 1960’s. As a consultant he was part of the team working on the Viking missions to Mars and his function was to assist work out tests to find out the presence, currently or historically, of life on that planet. This directs him to question the nature and core definition of life itself. It also pictured him to the then still remarkably bright views of Earth from space. Because of the information presented to him there he was able to evaluate the geophysical relationship between Earth and its adjacent neighbors, Mars and Venus, and question himself why our planet had been so victorious in maintaining and developing life when the others had been unsuccessful. Using the holistic view he asked why among of the three planets that had started life so equally only Earth, once it had established life, had managed to preserve an environment helpful to supporting life for so many an eons. His assumption is that Earth’s biosphere works in concert to keep up its equilibrium throughout a series of measures and counter measures that has reserved the environment in a restricted operating band for three and a half billion years.
Lovelock, J. (2000). Gaia: A New Look at Life on Earth. USA: Oxford University Press.