Maintenance

In any operating system whose goal is homeostasis, departures from the current steady stale caused by change in the energy fluxes or their response times will tend to be corrected and a new optimum sought which incorporates the changes. A system as experienced as Gaia is unlikely to be easily disturbed. Nevertheless, we shall have to tread carefully to avoid the cybernetic disasters of runaway positive feedback or of sustained oscillation. If, for example, the methods of climate control which I have postulated were subject to severe perturbation. we might suffer either a planetary fever or the chill of an ice age, or even experience sustained oscillations between these two uncomfortable States.

This could happen if, at some intolerable population density, man had encroached upon Gaia's functional power to such an extent that he disabled her. He would wake up one day to find that he had the permanent lifelong job of planetary maintenance engineer. Gaia would have retreated into the muds, and the ceaseless intricate task of keeping all of the global cycles in balance would be ours. Then at last we should be riding that strange contraption, the 'spaceship Earth'. and whatever tamed and domesticated biosphere remained would indeed be our 'life support system'. -- James Lovelock, Gaia: A New Look at Life on Earth