The Gaia Hypothesis in 10 minutes James Lovelock

1
The Gaia Hypothesis-in 10 minutes- James
Lovelock
Our planet in perspective Gaia explains the
constancy of our unstable atmosphere
Organisms and their environment evolve as a
single, self-regulating system
Lovelock, Nature, 426 (2003), 769-770
2
The Gaia Hypothesis-in 10 minutes-

• Gaia The Greek Earth goddess
• Name suggested by the novelist William Golding
• Dr. James Lovelock Chemist
• Dr. Lynn Margulis Microbiologist
• ...the physical and chemical condition of the
  Earths surface, atmosphere and oceans has been,
  and is actively made fit and comfortable by the
  presence of life itself From Gaia A new look
  at life on earth (1979)
• Model of the Earth as a complex interacting
  system that can be thought of as a single
  organism. Encyclopaedia Britannica

3
The Gaia Hypothesis-in 10 minutes-

• Evolution through manipulation of the abiotic
  environment
• Earth as a superorganism?
• Novel idea?
• J. Hutton (1726-1797) - geophysiology
• L. Thomas ...like a single cell
• Various religions
• Science vs. New Age
• Speculative adaptations
• Man as Gaias nervous system?
• Green light for pollution?
• Reproduction?
• Etc.

4
The Gaia Hypothesis-in 10 minutes-

• Weak (or influential) Gaia hypothesis
• Life influences earth (planetary) processes, i.
  e. has substantial effects on abiotic processes.
  Generally supported.
• Strong (or optimizing) Gaia hypothesis.
• Life controls planetary processes. Little
  support.

5
The Gaia Hypothesis-in 10 minutes-

• The Science
• Daisyworld

6
The Gaia Hypothesis-in 10 minutes-

• A possible mechanism for temperature control
• Di-methylsulfide (CH3-S-CH3) is produced by
  phytoplankton in the oceans.
• Oxidized in the atmosphere to form cloud
  condensation nuclei
• Clouds affect temperature

7
The Gaia Hypothesis-in 10 minutes-

• James Kirchner (UC Berkeley)

8
The Gaia Hypothesis-in 10 minutes-

• Theory vs. Metaphor
• ..a theory that is untestable is far worse than
  one that is merely false
• Lovelock Perhaps its Gaias value lies in its
  metaphor of a living earth. Which reminds us that
  we are part of it and that human rights are
  constrained by the needs of our planetary
  partners.