The Gaia Hypothesis is the theory that living organisms and inorganic material are part of a dynamic system that shape Earth's biosphere, in Lynn Margulis's words, a "super organismic system".
In 1969 the British scientist James Lovelock postulated that life on Earth regulates the composition of the atmosphere to keep the planet habitable. The novelist William Golding, Lovelock’s friend and neighbor, suggested Lovelock call the hypothesis Gaia, after the Greek Earth goddess. Although in its early exposition and in the popular press the Gaia hypothesis was understood as saying Earth itself was a living organism, the theory as Lovelock came to articulate it said rather that Earth acts like a living organism, with its living and nonliving components acting in concert to create an environment that continues to be suitable for life.
In a 2006 book, Lovelock made the argument that environmental degradation and climate change are testing Gaia’s capacity to self-regulate and maintain Earth’s habitability. He believes that it is already too late to avoid significant climate change, thus rendering large portions of our planet much less hospitable for humans. Sustainable development and renewable energy are two hundred years too late to be of much help; it is now time to direct greater efforts towards adaptation. Lovelock is an advocate of nuclear power as a short-term solution for maintaining energy demands, but other clean alternative energy sources are thought to be too little too late. Given the range of environmental stresses, he claims that human civilization will find it difficult to survive as is, with the human population experiencing significant decline during the next hundred years. Lovelock claims that Gaia’s self-regulation is likely to prevent any catastrophic wipeout of life on Earth, but the present course of action is unsustainable, and there will be changes to life on Earth one way or the other.
What use is Gaia? It has been a fruitful source of new research and an inspiration for environmentalists. It led to the discovery of the natural compounds dimethyl sulfide and methyl iodide, which transfer the essential elements sulfur and iodine from the oceans to the land. It showed how life in the soil and on the rocks increases the rate of removal of carbon dioxide from the air and so regulates both the levels of carbon dioxide and, consequently, climate. Its most daring prediction stated in 1987 by Robert Charlson, Lovelock, Meinrat Andreae, and Stephen Warren, was that the microscopic algae of the oceans are linked by their emission of a gas, dimethyl sulfide, with the clouds and with the climate. As Earth gets hotter, the theory says, these algae release more dimethyl sulfide into the atmosphere, which increases Earth’s cloud cover, which in turn cools the Earth: without clouds, the earth would be hotter by 10–20?C. This idea is crucial to the proper understanding of climate change. The authors received the Norbert Gerbier Prize and medal from The World Meteorological Office for this theory in 1988. Ten years later hundreds of scientists worldwide were studying the links between ocean algae, atmospheric chemistry, clouds, and climate. Climatologists and even physiologists have used Daisyworld in their research. Over the years, Gaia has changed the way scientists think. There is no better example of this change than the Amsterdam Declaration of 2001. A conference of environmental scientists in 2001 issued the declaration, which had as its first bullet point: “The Earth System behaves as a single, self-regulating system comprised of physical, chemical, biological and human components” (Open Science Conference 2001). Although not yet a full statement of Gaia theory, it a substantial advance on the separated view of earth and life sciences that went before.
Ionic/atomic silver is an effective antimicrobial at concentrations astronomical orders of magnitude below what is harmful to higher life forms. Concentrations necessary to sterilise drinking water (or by extension, body fluids – we are 70% water) contaminated with pathogens are 40-200 gamma / .04-.2ppm (1ppm = 1000 gamma) (Thomson N, Comprehensive Inorganic Chemistry, Pergamon, NY, 1973). Most colloidal silver available in South Africa is generated by a water purification device from the Gaia Research Institute, producing 1ppm of silver (and possibly a suggested microbicidal synergism with 5-15 drops of hydrogen peroxide). One teaspoon (5ml) of 1ppm colloidal silver in a glass (250ml) of water equals 20ppb. Since drinking water guidelines relate to lifetime exposure for the most susceptible sub-groups, calculated at 2 litres a day over an entire lifetime, one could safely consume 8 glasses each with 5 teaspoons (25 ml) of 1 ppm of colloidal silver every day without risk of argyria, the only and purely hypothetical risk to users. Most commonly used is a mere teaspoon in a glass of water 3 or 4 times daily.
Around the end of that , another unique event transpired with enormous portent for life’s journey on Earth: one microbe enveloped another, and both lived. Today's prevailing hypothesis is that an archaean enveloped a bacterium, either by predation or colonization, and they entered into a . Today’s leading hypothesis, , is that the archaean consumed hydrogen and the bacterium produced hydrogen, which formed the basis for their symbiosis. That unique event transpired around two bya and led to complex life on Earth. That enveloped bacterium was the parent of all on Earth today, which are the primary energy-generation centers in all animals. About 10% of the human body’s weight is mitochondria. If not for the red of and the in skin, humans would look purple, which is the mitochondria’s color. That purple color is probably because the original enveloped bacterium that led to the first mitochondrion was .
Gaia views Earth’s surface environment as a self-regulating system composed of all organisms, the atmosphere, oceans, and crustal rocks, which sustains conditions favorable for life. It sees the evolution of life and the evolution of Earth’s surface and atmosphere as a single process, not separate processes, as taught in biology and geology. Organisms evolve by a process of natural selection, but in Gaia, they do not merely adapt to the environment, they change it. Humans, clearly, are changing the atmosphere, the climate, and the land surfaces, but other organisms, mostly microscopic, have in the past made changes that were even more drastic. The appearance of oxygen in the air two billion years ago is but one of them. Gaia stands to Darwinism somewhat as relativity theory stands to Newtonian physics. It is no contradiction of Darwin’s great vision but an extension of it.
When investigating how ice ages begin and end, and feedbacks are considered. A positive feedback will accentuate a dynamic and a negative feedback will mute it. In the 1970s, and the author of today’s , , , which posits that Earth has provided feedbacks that maintain environmental . Under that hypothesis, environmental variables such as atmospheric and levels, levels, and Earth’s surface temperature have been kept relatively constant by a combination of geophysical, geochemical, and life processes, which have maintained Earth’s inhabitability. The homeostatic dynamics were mainly negative feedbacks. If positive feedbacks dominate, then “runaway” conditions happen. In astrophysics, are responsible for a wide range of phenomena. A runaway greenhouse effect may be responsible for . Climate scientists today are concerned that burning the hydrocarbons that fuel the industrial age . Mass extinctions are the result of Earth's becoming largely uninhabitable by the organisms existing during the extinction event. The ecosystems then collapse Mass extinction specialist recently proposed his as a direct challenge to the Gaia hypothesis.
Readers for the collective task that I have in mind need to become familiar with the scientific process, partly so they can develop a critical eye for the kinds of arguments and evidence that attend the pursuit of FE and other fringe science/technology efforts. For the remainder of this essay, I will attempt to refrain from referring to too many scientific papers and getting into too many details of the controversies. Following my references will help readers who want to go deeply into the issues, and many of them are as deep and controversial as the Snowball Earth hypothesis and aftermath has proven to be, or attempts to explain the . These are relatively new areas of scientific investigation, partly due to an improved scientific toolset and ingenious ways to use them. It is very possible that the controversies in those areas will diminish within the next generation as new hypotheses account for increasingly sophisticated data, and in the near future are nearly certain. But science is always subject to becoming dogmatic and hypotheses can prevail for reasons of wealth, power, rhetorical skill, and the like, not because they are valid. The history of science is plagued with that phenomenon, and probably will be as long as humanity lives in the era of scarcity.
In 1981 Lovelock answered the critics by creating the numerical model Daisyworld, an imaginary planet on which there were two species of plant, one light colored and the other dark colored. The planet was warmed by a star that, like Earth’s sun, grew hotter as time passed. When the star was cooler, each dark-colored daisy warmed itself by absorbing sunlight, until dark daisies predominated and warmed the planet; as the star grew hotter, each pale-colored daisy, by reflecting sunlight, kept itself and the planet cooler. The competition for space by the two daisy species kept the planet’s temperature constant, thus sustaining a habitable condition despite changes in the heat output of the star. The model showed that even without regulating anything other than themselves, organisms and their environment evolve together as a powerful self-regulating system. This demonstration, along with successful predictions of mechanisms for the regulation of the Earth’s climate and chemistry, put Gaia on a firm theoretical basis, which was strengthened by a further suite of models from the ecologists Tim Lenton (in 1998) and Stephan Harding (in 1999).
There is also evidence that life itself can contribute to mass extinctions. When the eventually , organisms that could not survive or thrive around oxygen (called ) . When anoxic conditions appeared, particularly when existed, the anaerobes could abound once again, and when thrived, usually arising from ocean sediments, they . Since the ocean floor had already become anoxic, the seafloor was already a dead zone, so little harm was done there. The hydrogen sulfide became lethal when it rose in the and killed off surface life and then wafted into the air and near shore. But the greatest harm to life may have been inflicted when hydrogen sulfide eventually , which could have been the final blow to an already stressed ecosphere. That may seem a fanciful scenario, but there is evidence for it. There is fossil evidence of during the Permian extinction, as well as photosynthesizing anaerobic bacteria ( and ), which could have only thrived in sulfide-rich anoxic surface waters. Peter Ward made this key evidence for his , and he has implicated hydrogen sulfide events in most major mass extinctions. An important aspect of Ward’s Medea hypothesis work is that about 1,000 PPM of carbon dioxide in the atmosphere, which might be reached in this century if we keep burning fossil fuels, may artificially induce Canfield Oceans and result in . Those are not wild-eyed doomsday speculations, but logical outcomes of current trends and , proposed by leading scientists. Hundreds of already exist on Earth, which are primarily manmade. Even if those events are “only” 10% likely to happen in the next century, that we are flirting with them at all should make us shudder, for a few reasons, one of which is the awesome damage that it would inflict on the biosphere, including humanity, and another is that it is entirely preventable with the use of technologies .