Earth system: Difference between revisions
No edit summary |
No edit summary |
||
| Line 9: | Line 9: | ||
=Archean= | =Archean= | ||
With each eon lasting a thousand million years, the Archean is the era from Earth's assembly 4.5 eons ago to the oxygen revolution 2.5 eons ago. Gaia theory suggests that life during the Archean adapted the Earth to make it a home. There emerged a self-regulating interaction between early photosynthesizers (cyanoacteria) who ''cooled'' the Earth by removing heat-trapping carbon-dioxide from the atmosphere and methanogen decomposers who ''warmed'' the Earth by converting [[bacteria]] into the greenhouse gases carbon dioxide and methane.<ref>Lovelock, ''Ages of Gaia'', 73.</ref> So, the photosynthesizers were like the light daisies of the Daisyworld model, and the decomposers were like the dark daisies. Together, they kept the planet | With each eon lasting a thousand million years, the Archean is the era from Earth's assembly 4.5 eons ago to the oxygen revolution 2.5 eons ago. Gaia theory suggests that life during the Archean adapted the Earth to make it a home. There emerged a self-regulating interaction between early photosynthesizers (cyanoacteria) who ''cooled'' the Earth by removing heat-trapping carbon-dioxide from the atmosphere and methanogen decomposers who ''warmed'' the Earth by converting [[bacteria]] into the greenhouse gases carbon dioxide and methane.<ref>Lovelock, ''Ages of Gaia'', 73.</ref> So, the photosynthesizers were like the light daisies of the Daisyworld model, and the decomposers were like the dark daisies. Together, they kept the planet at livable temperatures.<ref>Lovelock, ''Ages of Gaia'', 76.</ref> | ||
=Proterozoic= | =Proterozoic= | ||
| Line 17: | Line 17: | ||
A key self-regulatory mechanism of the Proterozoic involved the deposit of calcium carbonate on the oceanic floor. Through such deposits, bacteria converted toxic soluble calcium into insoluble calcium. Although calcium is essential for many life forms, too much of it is deadly, and this self-regulatory mechanism would have been crucial for many beings' survival.<ref>Lovelock, ''The Ages of Gaia'', 98.</ref> | A key self-regulatory mechanism of the Proterozoic involved the deposit of calcium carbonate on the oceanic floor. Through such deposits, bacteria converted toxic soluble calcium into insoluble calcium. Although calcium is essential for many life forms, too much of it is deadly, and this self-regulatory mechanism would have been crucial for many beings' survival.<ref>Lovelock, ''The Ages of Gaia'', 98.</ref> | ||
Another example of self-regulation involved salt-regulation. Few organisms can survive with an abundance of salt, and | Another example of self-regulation involved salt-regulation. Few organisms can survive with an abundance of salt, and oceans stayed within a safe salinity level. Various chemical reactions helped remove salt from the sea floor, and microorganisms deposited salt as sediments and as limestone.<ref>Lovelock, ''Ages of Gaia'', 98, 103.</ref> | ||
=Phanerozoic= | =Phanerozoic= | ||
Revision as of 14:17, 7 May 2019
The Earth is a self-regulating system according to Earth system science and its more radical predecessor known as Gaia theory. Living beings around the planet cooperate to stabilize the Earth's temperature, acidity, salinity, and atmosphere. Thus, the Earth does not function as a hierarchy or as merely a competitive struggle between all beings. Rather, members of a highly decentralized global network often cooperate to ensure mutual survival over millions and millions of years.
James Lovelock and Lynn Margulis first advanced the Gaia hypothesis, jointly publishing in Carl Sagan's journal Icarus. At first, they characterized the Earth as a living superorganism, drawing harsh criticism from reductionist scientists such as Richard Dawkins, who denounced the notion as "teleological." Critics like Dawkins asserted that the Earth cannot self-regulate since it does not have the consciousness necessary to plan and have foresight. Lovelock responded by programming a computer simulation called Daisyworld. In Daisyworld, sunlight-reflecting white daisies and sunlight-absorbing black daisies cooperated to stabilize the planet's temperature, allowing life to thrive for an extended period of time. The model demonstrated that planetary self-regulation does not require foresight or conscious planning.[1]
Today, the mainstream body of research called Earth system science draws heavily on Gaian ideas but, in an effort to fit into dominant scientific culture, removes the reference to the Greek earth goddess Gaia. In Amsterdam in 2001, over a thousand delegates signed a statement, “The Earth System behaves as a single, self-regulating system comprised of physical, chemical, biological and human components.”[2]
Archean
With each eon lasting a thousand million years, the Archean is the era from Earth's assembly 4.5 eons ago to the oxygen revolution 2.5 eons ago. Gaia theory suggests that life during the Archean adapted the Earth to make it a home. There emerged a self-regulating interaction between early photosynthesizers (cyanoacteria) who cooled the Earth by removing heat-trapping carbon-dioxide from the atmosphere and methanogen decomposers who warmed the Earth by converting bacteria into the greenhouse gases carbon dioxide and methane.[3] So, the photosynthesizers were like the light daisies of the Daisyworld model, and the decomposers were like the dark daisies. Together, they kept the planet at livable temperatures.[4]
Proterozoic
Around 2.5 eons ago, photosynthesizers transformed the atmosphere from being methane-dominated to being oxygen-dominated. This transformation heralded a new geological era, the Proterozoic, and it allowed the evolution of new kinds of life, including the evolution of eukaryotes.
A key self-regulatory mechanism of the Proterozoic involved the deposit of calcium carbonate on the oceanic floor. Through such deposits, bacteria converted toxic soluble calcium into insoluble calcium. Although calcium is essential for many life forms, too much of it is deadly, and this self-regulatory mechanism would have been crucial for many beings' survival.[5]
Another example of self-regulation involved salt-regulation. Few organisms can survive with an abundance of salt, and oceans stayed within a safe salinity level. Various chemical reactions helped remove salt from the sea floor, and microorganisms deposited salt as sediments and as limestone.[6]
Phanerozoic
Lasting from 600 million years ago until today, the Phanerozoic marks the time when organisms evolved to be large enough that they could be seen with a human's naked eye.[7] During this period, the carbon cycle marked one example of planetary self-regulation, in which the vegetation sequestered carbon and produced oxygen, keeping atmospheric carbon dioxide within levels manageable for most life on Earth. This process has, of course, been disrupted by the capitalist system's unprecedented levels of deforestation and greenhouse gas emissions.
Resistance
Raoul Vaneigem, formerly a theorist of the Situationist International, argues that the Earth engages in resistance to the capitalist system:
[N]ature has unpredictable fits of anger, sudden jolts that threaten the edifice of civilization. And the moment it refuses to produce, nature, like workers in revolt, is deemed stupid, pitiless and cruel.[8]
- ↑ James Lovelock, The Ages of Gaia: A Biography of Our Living Earth, Updated and Revised (New York and London: W.W. Norton & Company, 1988), 8, 34-37.
- ↑ http://www.colorado.edu/AmStudies/lewis/ecology/gaiadeclar.pdf. James Lovelock, The Revenge of Gaia: Earth's Climate Crisis & the Fate of Humanity (New York: Basic Books, 2006), 25.
- ↑ Lovelock, Ages of Gaia, 73.
- ↑ Lovelock, Ages of Gaia, 76.
- ↑ Lovelock, The Ages of Gaia, 98.
- ↑ Lovelock, Ages of Gaia, 98, 103.
- ↑ Lovelock, Ages of Gaia, 119.
- ↑ Raoul Vaneigem, The Movement of the Free Spirit: General Considerations and Firsthand Testimony Concerning Some Brief Flowerings of Life in the Middle Ages, the Renaissance and, Incidentally, Our Own Time trans. Randall Cherry and Ian Patterson (New York: Zone Books, 1998), 32.
