Tuesday, December 11, 2012

Gaia hypothesis

On behalf of the Government and people of Kiribati I am pleased to welcome you to this web site which is designed to bring you information and updates on our situation in Kiribati.

You will be aware that our small country is facing critically difficult times with regard to climate change issues & its impact on our future. We hope the content and links from this site will assist you in understanding more clearly our situation. I am also pleased to refer you to the short video clip "Kiribati - A Call to the World" here on this page which very much represents the concerns and feelings of our people.

We thank you sincerely for your interest, and refer you to this site, or the contacts detailed here, if any further information is required. In closing may I offer our traditional Kiribati blessing—Te Mauri, Te Raoi ao Te Tabomoa—may good health, peace and prosperity be with you all.

Anote Tong
President of the Republic of Kiribati

The Gaia hypothesis, also known as Gaia theory or Gaia principle, proposes that all organisms and their inorganic surroundings on Earth are closely integrated to form a single and self-regulating complex system, maintaining the conditions for life on the planet.

The scientific investigation of the Gaia hypothesis focuses on observing how the biosphere and the evolution of life forms contribute to the stability of global temperature, ocean salinity, oxygen in the atmosphere and other factors of habitability in a preferred homeostasis. The Gaia hypothesis was formulated by the chemist James Lovelock and co-developed by the microbiologist Lynn Margulis in the 1970s. Initially received with hostility by the scientific community, it is now studied in the disciplines of geophysiology and Earth system science, and some of its principles have been adopted in fields like biogeochemistry and systems ecology. This ecological hypothesis has also inspired analogies and various interpretations in social sciences, politics, and religion under a vague philosophy and movement.

Since life started on Earth, the energy provided by the Sun has increased by 25% to 30%;[8] however, the surface temperature of the planet has remained within the levels of habitability, reaching quite regular low and high margins. Lovelock has also hypothesised that methanogens produced elevated levels of methane in the early atmosphere, giving a view similar to that found in petrochemical smog, similar in some respects to the atmosphere on Titan.[9] This, he suggests tended to screen out ultraviolet until the formation of the ozone screen, maintaining a degree of homeostasis. The Snowball Earth[10] research, as a result of "oxygen shocks" and reduced methane levels, that led during the Huronian, Sturtian and Marinoan/Varanger Ice Ages the world to very nearly become a solid "snowball" contradicts the Gaia hypothesis somewhat, although the ending of these Cryogenian periods through bio-geophysiological processes accords well with Lovelock's theory.

Processing of the greenhouse gas CO2, explained below, plays a critical role in the maintenance of the Earth temperature within the limits of habitability.

The CLAW hypothesis, inspired by the Gaia theory, proposes a feedback loop that operates between ocean ecosystems and the Earth's climate.[11] The hypothesis specifically proposes that particular phytoplankton that produce dimethyl sulfide are responsive to variations in climate forcing, and that these responses lead to a negative feedback loop that acts to stabilise the temperature of the Earth's atmosphere.

Currently this Gaian homeostatic balance is being pushed by the increase of human population and the impact of their activities to the environment. The multiplication of greenhouse gases may cause a turn of Gaia's negative feedbacks into homeostatic positive feedback. According to Lovelock, this could bring an accelerated global warming and mass human mortality.

The importance of the large number of species in an ecosystem, led to two sets of views about the role played by biodiversity in the stability of ecosystems in Gaia theory. In one school of thought labelled the "species redundancy" hypothesis, proposed by Australian ecologist Brian Walker, most species are seen as having little contribution overall in the stability, comparable to the passengers in an aeroplane who play little role in its successful flight. The hypothesis leads to the conclusion that only a few key species are necessary for a healthy ecosystem. The "rivet-popper" hypothesis put forth by Paul R. Ehrlich and his wife Anne H. Ehrlich, compares each species forming part of an ecosystem as a rivet on the aeroplane (represented by the ecosystem). The progressive loss of species mirrors the progressive loss of rivets from the plane, weakening it till it is no longer sustainable and crashes.[14]

Later extensions of the Daisyworld simulation which included rabbits, foxes and other species, led to a surprising finding that the larger the number of species, the greater the improving effects on the entire planet (i.e., the temperature regulation was improved). It also showed that the system was robust and stable even when perturbed. Daisyworld simulations where environmental changes were stable gradually became less diverse over time; in contrast gentle perturbations led to bursts of species richness. These findings lent support to the idea that biodiversity is valuable.[15]

This finding was later proved in a eleven-year old study of the factors species composition, dynamics and diversity in successional and native grasslands in Minnesota by David Tilman and John A. Downing wherein they discovered that "primary productivity in more diverse plant communities is more resistant to, and recovers more fully from, a major drought". They go on to add "Our results support the diversity stability hypothesis but not the alternative hypothesis that most species are functionally redundant

Corporate Knights presents Dr. James Lovelock, originator of The Gaia Hypothesis (also known as Gaia Theory), discussing the need for human adaptation and survival in a coming era of massive environmental change due to global heating. Part 1 in a series of 5 as Dr. Lovelock lectures on his latest book, "The Vanishing Face of Gaia".

Stay tuned to www.corporateknights.ca for Episodes 2-5. Part 2 will be available July 2.

Videography & Editing by Jon-Erik Lappano, Editorial Assistant.

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