1. The Gaia Hypothesis Gaia Hypothesis

2. James Lovelock 1979 Earth is a “super organism” It is alive Like one single organism Name is from Greek Earth Godess - Gaia

3. One step further than “Mother Earth” Lovelock is a reputable scientist with a hypothesis that is pretty far out Proposed as a testable scientific hypothesis

4. “ Gaia is a complex entity involving the Earth’s biosphere, atmosphere, oceans, and soil; the totality constituting a feedback of cybernetic system which seeks and optimal physical and chemical environment for life on this planet” James Lovelock

5. How Does Gaia Work? Life regulates the climate and atmosphere at an optimum for itself Homeostasis

6. But, the earth is mostly dead rock. How can it be alive? A redwood tree is mostly dead, but it is very clearly alive

7. Homeostatic Mechanisms on Earth Atmospheric chemistry is tightly controlled by Gaia At 25% oxygen fires would be very much more frequent Less than 21% oxygen would prevent multicellular animal life Temperature control Albedo – reflectivity of earth Clouds prevent heating of earth Heat produces clouds because of increased evaporation James Lovelock with David S.

8. Lovelock’s Arguments for GAIA Human activities will not affect the Earth permanently Gaian homeostatic mechanisms will control Earth’s environments The problem is that Earth’s reaction to human activities may actually threaten our existence The Hour with James Lovelock

9. Discussion Questions What are the major points of the Gaia Hypothesis? According to the Gaia Hypothesis, how is Earth unique? What is climate change a sign of? What are the implications for Canada according to Lovelock? Does James Lovelock feel he is listened to by others? How and why do people disagree with Lovelock?

10. Assignment Do you agree or disagree with the Gaia Hypothesis? You are required to use at least 3 references from the video or readings below to support you stance. Be sure to use proper referencing format. http://www.guardian.co.uk/science/2008/apr/28/scienceof climatechange.biodiversity http://www.gaiatheory.org/overview/