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The Gaia Hypothesis: Earth as a Self-Regulating System
1. The Gaia Hypothesis Mariana Botero IE- MGEC Data Management and Information Design
2. Gaia Gaia in Greek meant earth, land or mother In Greek mythology, Primal Goddess of Earth, of the order of Mother Titan or Great Titan Symbolized Mother Nature or Earth Mother
3. Holism Holism: Idea that all properties of a system cannot be explained by component parts alone, but as a whole Developed by Aristotle in the Metaphysics, “the whole is different from the sum of its parts”
4. Gaia Theory or Feedback Loop Theory Homeostasis: equilibrium, balance Different processes contribute to overall equilibrium Biomass makes conditions on the planet hospitable through surface temperature, atmospheric composition, and ocean salinity Feedback consisted of the Earth supporting Life, and Life supporting the Earth
5. Surface Temperature Global surface temperature has remained constant, despite a 25-30% increase in the energy provided by the Sun Example of the Earth maintaining conditions hospitable for Life
6. Atmospheric Composition Atmosphere: 79% nitrogen, 20.7% oxygen, 0.03% carbon dioxide Methane should not exist; combustible in an oxygen atmosphere Remains constant, should be unstable Stability can only be maintained through removal or production by living organisms Example of Life maintaining conditions optimal for Earth
7. Ocean Salinity Constant at 3.4% for a long time Cells require salinity but do not tolerate above 5% River salts should have raised salinity much higher Stability maintained through influence of organic processes
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9. Real Application Simple homeostatic mechanisms generally accepted (i.e. when atmospheric CO2 rises, biomass increases and thus removal of more CO2) Lovelock attributed this to systemic Darwinian evolution; creatures that improve their environment for survival do better than those that damage the environment
10. Criticism I- Meaning of Life Critics said a criteria of life is the ability to reproduce Lovelock defined life as self-preserving system of feedback loops Instellar travel and carrying conditions of life elsewhere could signify planetary spore
11. Criticism II - Theological Gaia acted intentionally, purposefully Lovelock said intentionality was metaphorical, no religious implications Theory criticized for having theological connotations and not scientific enough
12. Radicalism Surrounding Theory Extended holistic lifeform to galaxies, “we are made of stardust. Life in inherent in nature” Fires, metals, crystals as living organisms Is it possible then to have non-life? Gaia Movement- political branch concerned with how humans might live more sustainably within “living system” Earth is conscious and part of universal evolution, a single organism Mystical and metaphysical interpretations
13. Defense Gaia not an organism, but the interaction among organisms Planet behaves as a physiological system in certain limited ways Surface of the planet regarded as alive “Gaia is just a symbiosis as seen from space”
14. Ecological Science Modified Gaia Theory agrees with science that Earth is the ultimate object of ecological study Earth System Science studies interactions between biota, oceans, geosphere and atmosphere Concern common to both of human modification to global environment and implications for Life and human well-being
15. Climate Change 4 Conclusions: Earth System a single, self-regulating system with complex interactions and feedbacks Anthropogenic changes are clearly identifiable beyond natural variability These changes have multiple effects that affect the Earth System in complex ways The nature of changes now occurring simultaneously, their magnitudes and rates, are unprecedented
16. Uninhabitable Planet Lack of respect of humans for Gaia is testing capacity for homeostasis (damage to rainforests, reduction of biodiversity, greenhouse gas emissions, warming oceans, etc.) Activities are eliminating negative feedbacks and increasing global warming positive feedbacks By 2040, 6 billion inhabitants will have been affected or killed by floods, droughts, and famine A 4o temperature rise will eliminate 90% of life on the planet Lovelock believes it is too late to repair damage, “we are about to take an evolutionary step and my hope is that the species will emerge stronger”
17. Gaia Spore Carl Sagan said that from cosmic point of view, “space probes have character of a planet preparing to go to seed” Biosphere will multiply in future by colonizing other planets Humankind will be the primer for Gaia´s reproduction Human interstellar exploration, colonization, and terraforming other planets may be Gaia´s spore
Editor's Notes
Original caption: "View of the Earth as seen by the Apollo 17 crew traveling toward the moon.
Space exploration in the past five decades has turned the low orbit of our planet into a hovering junkyard, a mix of dead satellites and discarded rocket hardware. This space garbage — euphemistically referred to as “space debris” — isn’t just an eyesore for visiting space aliens; it also poses a serious hazard to space shuttle missions, as well as the International Space Station. This junk isn’t just floating in space, it’s hurtling around the earth at 18,000 mph. A collision could have devastating consequences. It was exactly this scenario that NASA scientists feared this week, when it was reported that astronauts on the station might have to evacuate due to a possible collision with a piece of an old Soviet satellite. Luckily, the astronauts got good news today that the space station was safe from space junk. It was a close call, though; because it was deemed too late for NASA to move the station, the crew had taken shelter in the Russian Soyuz before receiving the all-clear today. The UN passed a set of space-debris guidelines in 2007, but obviously more serious action needs to be taken to confront this issue.
