Anyone who has seen the movies “Avatar” or “The Day After Tomorrow”, has probably already come across the idea of “living” planets which react in response to environmental changes initiated by its inhabitants, in a way similar to how most organisms respond to stimuli in their environment. While this concept may sound like science fiction it is actually founded in a scientific hypothesis known as the Gaia hypothesis- the belief that earth itself is a self regulating system whose behavior resembles in some ways that of an organism. The hypothesis was formed by James Lovelock in the 1960’s while he was studying the atmospheric compositions of Venus and Mars on behalf of NASA.
While conducting his research Lovelock noticed that compared to Earth, which has an atmosphere composed of multiple gases, Venus and Mars had atmospheres almost entirely composed of inert gases such as carbon dioxide. Further research into these contrasting gas systems led Lovelock to believe that the reason for earth multiple gases lay in the activities of Earth’s biosphere (specifically its clouds, mountains, ice caps, oceans and organisms) which regulate temperature and climate, and produce gases in the atmosphere which are sustainable for life. This concept was illustrated through a hypothetical example Lovelock created called Daisyworld; the mechanics of which has since been proven through computer simulations. In the simulation Daisyworld is a planet containing only black daisies and white daisies, which is lit by a sun that grows hotter over time. In this biosphere white daisies reflect the sun’s heat, thereby cooling the surface of the planet, while the black daisies absorb heat, thereby warming the planet’s surface. In Daisyworld Joel de Rosnay explains: “The simulation… starts with a low temperature. The black daisies which absorb the heat of the sun better, survive, develop and occupy a large area. As a result, the temperature of the soil increases becoming more favorable to life. The black daisies reproduce at a high rate but cover too much area, and temperature increases above a critical point; the black daisies die off en masse. But the white ones adapt, develop and colonize large areas, reflecting the heat and cooling the planet again. The temperature then drops – too much. The white daisies die and the black ones return in profusion. After a certain number of fluctuations a mosaic of black and white areas begin to coexist and co-evolve on the planet’s surface. Individual daisies are born and die, but the two populations, through successive heating and cooling maintain an average temperature favorable to life of both species, and this temperature fluctuates around the optimal balance.
In theory the Gaia hypothesis therefore works. However if the world actually does perform self regulating activities then what is the role of humans in the biosphere and what effect do our actions have. Gaian theorists not that “Because the earth mass and material elements are fixed elements must be recycled to make them available for other processes; otherwise the system would run down and the earth would be as dead as the moon. This is largely the responsibility of the living organisms which inhabit the planet (i.e. mankind)”. If this is true then I believe that it can be argued that the neo-classical economical view of economic development and the industrialized and resource depleting economies it has spawned may push the human race into near extinction. Say for example in Daisyworld white daisies became a precious commodity. In a society which views development in purely quantitatively based economic terms this would mean the mass depletion of white daisies to increase GDP. However it would also cause an unnatural growth in the number of black daisies which in turn would result in ever increasing temperatures until the point that organisms living within the biosphere (such as humans) would face extinction. In fact Lovelock has predicted that within this century events such as those depicted in “The Day After Tomorrow” will certainly occur.
While there any numerous aspects of Gaia theory which are disputed and criticised (particularly from evolutionary biologists), it is certainly an interesting concept to consider; because even though the Daisyworld example is only a simplistic analogy of Earth’s own complicated biosphere, the depletion of resources which leads to the elimination of biosphere services such as those offered by white daisies is no different to the natural resource depletion and elimination of biosphere services offered by Earth’s natural capital.
If you want to learn more about Gaia and James Lovelock here are some great videos: