Content: An exposition of the Gaia hypothesis, "a complex entity involving earths biosphere, atmosphere, oceans, and soil; the totality constituting a feedback or cybernetic system which seeks an optimal physical and chemical environment for life on this planet. The maintenance of relatively constant conditions by active control may be conveniently described as 'homeostasis' ".
Relevance: If it is valid to think about earth as a system, then the human activity system which I describe is an integral part of and a sub-system of Gaia