The Concept of ‘Gaia’


The Gaia theory of James Lovelock proposes that the Earth is a self‐regulating system, or super‐organism, maintaining conditions hospitable to contemporary planetary biota. Objections to this theory, concerning its alleged untestability and circularity, are considered and countered. Favourable evidence includes Lovelock's Daisyworld model of a planet regulating its own temperatures and thus maintaining homeostasis, and his discoveries of actual regulatory mechanisms such as the biological generation of dimethyl sulphide, which removes sulfur from the oceans and seeds clouds whose albedo reduces solar radiation (a negative feedback mechanism). After some decades of scepticism, sections of the scientific community have partially endorsed Gaia theory, accepting that the Earth system behaves as if self‐regulating. Whether or not this theory is acceptable in full, it has drawn attention to the need for preserving planetary biological cycles and for the planetary dimension to be incorporated in ethical decision‐making, and thus for a planetary ethic.

Key Concepts

  • James Lovelock hypothesises that the planetary physical and biological system is a self‐regulating super‐organism.
  • There were precedents before Lovelock for ascribing life either to the planet or to the universe.
  • James W. Kirchner presents Gaia hypotheses as either unoriginal or untestable.
  • Lovelock demonstrates that Gaia theory is both original and testable, albeit indirectly.
  • Lovelock's theory can readily escape the charge of circularity.
  • Predictions of Gaia theory include the existence of biologically generated mechanisms of planetary regulation.
  • Lovelock's discovery of dimethyl sulphide discloses such a mechanism for the regulation of oceanic sulfur.
  • Both atmospheric oxygen and atmospheric nitrogen turn out to be biologically generated and maintained.
  • Philosophers such as Stephen Clark and Mary Midgley have made Gaia a symbol for the planetary thinking currently needed.
  • The Amsterdam Declaration of planetary scientists (Moore et al., 2001) accepted aspects of Gaia theory, without explicitly accepting the theory's planetary goal.

Keywords: Daisyworld model; dimethyl sulphide; feedback mechanisms; Gaia; homeostasis; Lovelock, James; planetary ethic; self‐regulating system; super‐organism; testability


Allaby M (1996) Basics of Environmental Science, 2nd edn. London and New York: Routledge.

Charlson RJ, Lovelock JE, Andreae MO and Warren SG (1987) Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate. Nature 326: 655–661.

Clark SR (1983) Gaia and the forms of life. In: Elliot R and Gare A (eds) Environmental Philosophy: A Collection of Readings, pp. 182–197. St. Lucia, Queensland, London and New York: University of Queensland Press.

Davis ST (1997) God, Reason and Theistic Proofs. Edinburgh: Edinburgh University Press.

Dawkins R (1982) The Extended Phenotype. Oxford and San Francisco: W H Freeman & Co.

Kirchner JW (1992) The Gaia hypotheses: are they testable? Are they useful? In: Schneider SH and Boston PJ (eds) Scientists on Gaia. Cambridge: MIT Press (reprinted in Pojman LP (ed.) (1994) Environmental Ethics: Readings in Theory and Application, pp. 146–154. Boston, MA and London, UK: Jones and Bartlett).

Lenton TM (1998) Gaia and natural selection. Nature 394: 439–447.

Lovelock JE, Maggs R and Rasmussen RA (1972) Atmospheric dimethyl sulphide and the natural sulphur cycle. Nature 237: 452–453.

Lovelock JE (1979) Gaia: A New Look at Life on Earth. Oxford and New York: Oxford University Press.

Lovelock JE (1990) Hands up for the Gaia hypothesis. Nature 344: 100–102.

Lovelock JE (2006) The Revenge of Gaia: Why the Earth is Fighting Back – and How We Can Still Save Humanity. London and New York: Penguin.

Midgley M (2001) Gaia: The Next Big Idea. London: Demos.

Moore B III, Underdal A, Lemke P, et al. (2001) Amsterdam Declaration on Earth System Science. (accessed 11 April 2016).

Schwartzman DW and Volk T (1989) Biotic enhancement of weathering and the habitability of Earth. Nature 340: 457–460.

Watson AJ and Lovelock JE (1983) Biological homeostasis of the global environment: the parable of Daisyworld. Tellus 35B: 284–289.

Further Reading

Attfield R (2014) Environmental Ethics: An Overview for the Twenty‐First Century, 2nd edn. Cambridge: Polity.

Attfield R (2015) The Ethics of the Global Environment, 2nd edn. Edinburgh: Edinburgh University Press.

Joseph LE (1990) Gaia: The Growth of an Idea. London: Arkana (Penguin Books).

Kump LR, Kasting JF and Crane RG (2010) Earth System. Upper Saddle River, New Jersey: Prentice‐Hall.

Lovelock JE (1988) The Ages of Gaia. New York: WW Norton.

Lovelock JE (2001) Homage to Gaia, the Life of an Independent Scientist. Oxford and New York: Oxford University Press.

Lovelock JE (2005) Gaia: Medicine for an Ailing Planet. London: Gaia Books.

Margulis L (1998) The Symbiotic Planet. London: Phoenix Press.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Attfield, Robin, and Attfield, Kate(Aug 2016) The Concept of ‘Gaia’. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0026698]