GAIA: The Earth System

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GAIA The Earth System
James Kasting Professor of Geosciences 443 Deike
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GaiaThe Greek goddess

• Gaia is Mother Earth. She is from whom everything
  comes, but she is not quite a divinity, because
  she is Earth. She bore the Titans as well as
  monsters like the hundred armed men, and some of
  the Cyclopes - others were sons of Poseidon. She
  was the daughter of Chaos, and the mother of all
  creatures (according to some). She was the first
  and the last, and wanted all of her children, no
  matter what. She was primarily spoken of as a
  Mother of other Gods, rather than having her own
  myths.

http//www.paleothea.com/Majors.html
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The Gaia Hypothesis
First presented in the 1970s by James Lovelock
http//www.ecolo.org/lovelock
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The Gaia Hypothesis First presented in the
1970s by James Lovelock Lynn Margulis was an
early supporter, and she pointed out the
importance of microbial life
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• The Gaia Hypothesis
• Earth is a self-regulating system

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• The Gaia Hypothesis
• Earth is a self-regulating system
• The system includes both life and the physical
  world

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• The Gaia Hypothesis
• Earth is a self-regulating system
• The system includes both life and the physical
  world
• The system is capable of maintaining a surface
  environment that is suitable for life

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Gaia analogy

• Redwood trees are like Gaia because 97 of their
  tissues are dead. The wood of the trunk and the
  bark of the tree are dead. Only a small rim of
  cells along the periphery of the trunk is living.
  The trunk of the tree is similar to the Earth's
  lithosphere with a thin layer of living organisms
  spread across its surface. The bark, like the
  atmosphere, protects the living tissues, and
  allows for the exchange of biologically important
  gases, such as carbon dioxide and oxygen.

http//www.oceansonline.com/gaiaho.htm
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• Three Interpretations of the Gaia Hypothesis
• Theological or teleological
• Earth System is sensitive
• Earth System is resilient

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• Theological or Teleological View
• Earth controls its own destiny
• Optimizing Gaia The biota optimize climate
• for their own benefit
• (not part of Lovelocks definition of Gaia)

Teleology the study of design or purpose in
natural phenomina
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• View that the Earth System is Sensitive
• The system is interconnected, and a small
  perturbation can influence the whole system
• Certainly is true with respect to the weather
• The butterfly effect A butterfly flapping its
  wings in the Amazon can influence weather
  patterns globally a few days later
• Probably not literally true, but nevertheless
  this is an illustration of chaos,which is
  observed in weather simulations

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• View that the Earth System is Resilient
• The system can adapt to perturbations
• This should not be interpreted as meaning that we
  can do anything we like, e.g., emit large amounts
  of CO2, and nothing will happen as a result...

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• Scientific Implications of Gaia Hypothesis
• A new view of the Earth as one system
• Not really that newVernadsky had
• proposed this back in the early part of
• the last century
• From this view emerged Earth System Science

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Earth System Science The study of the
relationships among system components, and the
influence of many processes (including life) on
the evolution of the global environment.
http//www.earthsystemschool.mpg.de/web/imprs_prof
ile.jpg