Gaia hypothesis

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The concept, formulated by J. Lovelock (1988), that the entire planet earth—the atmosphere, ecosphere, geosphere, and hydrosphere—is a single ecosystem, or indeed, organism, which regulates itself by feedback mechanisms between the abiotic and biotic components of the system. To some extent, therefore, the ecosystem can moderate the effects of any changes made to it; it is, in some degree, self-regulatory, and tending to equilibrium.

It is argued that human agency is overriding this regulatory mechanism, tipping the biosphere out of equilibrium. This hypothesis stresses the overriding importance of the entire planetary ecosystem, rather than the health of any individual species.