The Earth immune system is a controversial proposal, claimed to be a consequence of the Gaia hypothesis. The Gaia hypothesis holds that the entire earth may be considered a single organism (Gaia). As a self-maintaining organism, Earth would possess an immune system of some sort in order to maintain its health.
Some proponents of this speculative concept, for example, hold that humankind can be considered an "infection" of Gaia, and that AIDS is an attempt by this immune system to reject the infection. "Cancer" might be a more accurate term, as humans evolved within Gaia, and are not external invaders. An opposite view is that humankind is Gaia's immune system itself, perhaps evolved to avert future catastrophes such as the Permian and Cretaceous mass extinctions of species.
James Lovelock's book "Gaia's Revenge" suggests that Gaia has many mechanisms for eliminating civilisations that do harm through greenhouse gas emissions and global warming, but suggests that with increasing heat being received from the sun, Gaia's ability to "bounce back" as it did after the Permian and Cretaceous extinction events, may be increasingly compromised.
Famous quotes containing the words immune system, earth, immune and/or system:
“The moral immune system of this country has been weakened and attacked, and the AIDS virus is the perfect metaphor for it. The malignant neglect of the last twelve years has led to breakdown of our country’s immune system, environmentally, culturally, politically, spiritually and physically.”
—Barbra Streisand (b. 1942)
“Our roots are in the dark; the earth is our country. Why did we look up for blessing—instead of around, and down? What hope we have lies there. Not in the sky full of orbiting spy-eyes and weaponry, but in the earth we have looked down upon. Not from above, but from below. Not in the light that blinds, but in the dark that nourishes, where human beings grow human souls.”
—Ursula K. Le Guin (b. 1929)
“The moral immune system of this country has been weakened and attacked, and the AIDS virus is the perfect metaphor for it. The malignant neglect of the last twelve years has led to breakdown of our country’s immune system, environmentally, culturally, politically, spiritually and physically.”
—Barbra Streisand (b. 1942)
“The dominant metaphor of conceptual relativism, that of differing points of view, seems to betray an underlying paradox. Different points of view make sense, but only if there is a common co-ordinate system on which to plot them; yet the existence of a common system belies the claim of dramatic incomparability.”
—Donald Davidson (b. 1917)