New study proposes solution to long-running debate as to how stable the Earth system is

June 10, 2013, University of Southampton

Researchers at the University of Southampton have proposed an answer to the long-running debate as to how stable the Earth system is.

The Earth, with its core-driven magnetic field, oceans of , dynamic climate and abundant life is arguably the most complex system in the known Universe. Life arose on Earth over three and a half billion years ago and it would appear that despite planetary scale calamities such as the impacts of massive meteorites, runaway and increases in brightness of the Sun, it has continued to grow, reproduce and evolve ever since.

Has life on Earth simply been lucky in withstanding these events or are there any self-stabilising processes operating in the that would reduce the severity of such perturbations? If such planetary processes exist, to what extent are they the result of the actions of life?

Forty years ago, James Lovelock formulated his Gaia Hypothesis in which life controls aspects of the planet and in doing so maintains conditions that are suitable for widespread life despite shocks and perturbations. This hypothesis was and remains controversial in part because there is no understood mechanism by which such a planetary self-stabilising system could emerge.

In research published in PLOS Computational Biology, University of Southampton lecturer Dr James Dyke and Iain Weaver detail a mechanism that shows how when life is both affected by and alters environmental conditions, then what emerges is a control system that stabilises environmental conditions. This control system was first described around the middle of the 20th Century during the development of the cybernetics movement and has until now been largely neglected. Their findings are in principle applicable to a wide range of real world systems - from to aquatic ecosystems up to and including the entire biosphere.

Dr Dyke says: "As well as being a fascinating issue in its own right, we quite desperately need to understand what is currently happening to the Earth and in particular the impacts of our own behaviour.

"Pretty much whatever we do, will carry on, just as it did for the previous 3.5 billion years or so. It is only by discovering the mechanisms by which our living planet has evolved in the past can we hope to continue to be part of its future."

Explore further: Researchers find massive impacts dispersed chlorine, helped make Earth habitable

More information: "The emergence of environmental homeostasis in complex ecosystems" PLOS Computational Biology … journal.pcbi.1003050

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3.5 / 5 (4) Jun 10, 2013
Where are the testable consequences of this hypothesis?
1.3 / 5 (16) Jun 10, 2013
More of the same sophistry by those who pretend to know what "science' is about. In fact, even "science' doesn't disqualify conjectures for not having testable hypotheses. The first criterion "science' demands is that a hypothesis address observed situations. An unannounced but generally held prejudice is that it do so using conventional ideas. If you find a triangular pile of rocks in the middle of the desert, you can hypothesize a thinking being left it there, even if you don't see footprints.
But, consider, if the Gaia Hypothesis is true, even if no conventional mechanism can be seen to give rise to it, it only fits an already established pattern. The solar system's configuration has recently been declared unique of all observed systems. The earth is the only planet with a moon so placed that it exactly covers the sun. It looks very much like earth is not the result of random, inanimate influences by the work of God.
3.7 / 5 (6) Jun 10, 2013
Science does not declare 'truth' without testable hypotheses, and the tests themselves. Conjectures are characterized as possibilities only.

Religions, by contrast, are perfectly willing to declare 'truth' without testable hypotheses.

Any questions?
1.4 / 5 (11) Jun 11, 2013
The earth is the only planet with a moon so placed that it exactly covers the sun.
Would it blow your mind to learn this isn't exactly true?


"I fell into a burning ring of fire
I went down, down, down and the flames went higher
And it burns, burns, burns, the ring of fire
The ring of fire" - Johnny Cash

1 / 5 (3) Jun 11, 2013
See Vernadsky's concept of noosphere for remedy of specious Gaia palaver.
5 / 5 (1) Jun 12, 2013
It is interesting, but quick browsing (I may be mistaken) tests it as obviously wrong. Only external shocks are moving the system, i.e. there is no prediction of the Great Oxygenation Event et cetera.

@tadchem: Except for the glaring point above, it is a basic model and it would take some effort to test its valuable contribution (mechanism for homeostasis).

@tgs: This work, our your reference's, doesn't resolve the question as work is needed, and the current consensus is that Gaia is wrong.
5 / 5 (1) Jun 12, 2013
As for the creationist commenting on science, it is hilarious and makes deconverts from religion, see Dawkins's Convert's Corner. Pointing to a 'fact' and declaring "therefore magic exists" doesn't work. ('Fact' since it is not quite true, and is a temporary coincidence as the Moon is increasing orbital radius due to tidal braking.)

Even if it had been an actual fact, what would it signify? It helped our astronomers somewhat to early results, and seeing the frequency of Moons and planets it is a common phenomena around planets. Heck, I'm sure we have other planets or moons where the same rough overlap happens within our own system even.

Also, the godbotherers idea of science is mistaken. A hypothesis that "address observed situations" is exactly a (series of) tests.
1 / 5 (4) Jun 16, 2013
I think the system is similar to an electric feedback amplifier. If you give it positive feedback it goes from stable into oscillation. I think we are providing the feedback and it looks to me like our weather is going into oscillation mode. If I'm right we haven't seen anything yet as far as weather goes.
2.8 / 5 (11) Jun 16, 2013
I think the system is similar to an electric feedback amplifier. If you give it positive feedback it goes from stable into oscillation. I think we are providing the feedback and it looks to me like our weather is going into oscillation mode. If I'm right we haven't seen anything yet as far as weather goes.

Actually, the positive feedback that you cite drives the system to SATURATION.

For climate, the equivalent of saturation is reached when Earth's temperature rises to the point where the wavelengths of its re-radiated energy pass through the atmosphere in a total amount that offsets that being received from the Sun, so that a new equilibrium is established.

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