Environmental Management: Principles and practice

The Gaia hypothesis
Since the 1860s Darwin’s concept of evolution—adaptation of organisms to the
environment—has held sway (Goldsmith, 1990). The Gaia hypothesis, proposed in
1969 by James Lovelock, calls for some modification of evolutionary theory. Similar
views were expressed by James Hutton as early as 1785: he, and later Pierre Teilhard
de Chardin, suggested that the biosphere acted as a self-evolving homeostatic system.
The Gaia hypothesis received little support before the late 1980s, and is still much-
debated. However, there have been recent suggestions that there is a biologically
credible mechanism. If proven, this would be a strong argument for a holistic approach
to environmental management (Hunt, 1998).
There are several variations of the Gaia hypothesis (Lovelock and Margulis,
1973; Schneider, 1990:8) but, whichever variant is accepted, it runs counter to the
prevailing attitude in the west that humans can exercise what controls they want over
the Earth (Lovelock, 1979; 1988; 1992; Watson, 1991). Whether or not they accept
the hypothesis, many have been stimulated by it to think carefully about environment
and development issues. For example, it has helped provoke valuable research into
the global carbon cycle. The Gaia hypothesis also provides a framework for people-
environment study that is holistic (Levine, 1993).
Broadly, the hypothesis suggests that life on Earth has not simply adapted to
the conditions it encountered, but has altered, and controls the global environment to
keep it habitable in spite of disruption from things like changes in solar radiation or
occasional planetesimal strikes. The hypothesis seeks to explain the survival of life
on Earth by treating the organic and physical environment as two parts of a single
system (‘Gaia’) in which biotic components act as regulators that so it can control
and repair itself (this is not a conscious process, nor is there implied a design or
purpose). Temperature and composition of the Earth’s atmosphere, according to the
hypothesis, are regulated by its biota, the evolution of which is influenced by the
factors regulated. Without Gaian regulation, the suggestion is that average global
temperatures would be more extreme, and atmospheric oxygen would probably be
locked up in rocks.
In effect, the Earth is seen as a superorganism, a single homoeostatic system
with feedback controls maintaining global temperature, atmospheric gases and

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availability of nutrients. The controls involve a number of biogeochemical cycles,
notably those of carbon dioxide, nitrogen, oxygen, sulphur, carbon and phosphorus.
The system functions in the ‘interests’ of the whole physical environment and biota:
the whole is greater than the sum of the parts. The implications are that humans are