Environmental Engineering Reference
In-Depth Information
From Gaia hypothesis to Gaia theory
The Gaia hypothesis was first formulated by James Lovelock and Lyn Margulis in
the 1960s and 1970s and is a clear example of systems thinking. It has been both
highly influential and quite controversial, not least in its practical implications for
sustainable development. Basically, the idea is that the Earth acts as a self-organizing
system, ensuring life, in its various forms, co-evolves in tandem with changes to the
physical configuration of the planet's animate and inanimate components. This self-
regulation is dynamic. The Earth seeks accommodation and balance in the face of
a large number of internal and external factors. Some proponents of Gaia see the
Earth itself as an organism, with the Earth's systems manipulating climate to ensure
life continues to emerge and exist. Lovelock (1979: 10) initially conceived Gaia as
a
teleological
process consisting of:
The entire range of living matter on Earth, from whales to viruses and from
oaks to algae, could be regarded as constituting a single living entity capable of
maintaining the Earth's atmosphere to suit its overall needs and endowed with
faculties and powers far beyond those of its constituent parts. [Gaia can be
defined] as a complex entity involving the Earth's biosphere, atmosphere, oceans
and soil, the totality constituting a feedback of
cybernetic systems
which seeks
an optimal physical and chemical environment for life on this planet.
Following considerable criticism and debate within and beyond the scientific
community, Lovelock refined his ideas, and by the turn of the century Gaia had
become firmly established in the intellectual landscape of environmentalists, many
scientists, sustainability practitioners and New Age travellers. In the second edition
of
The Ages of Gaia
, Lovelock wrote:
The name of the superorganism, Gaia, is not a synonym for the biosphere. The
biosphere is defined as that part of the Earth where living things normally exist.
Still less is Gaia the same as the biota, which is simply the collection of all
individual living organisms. The biota and biosphere taken together form part
but not all of Gaia. Just as the shell is part of a snail, so the rocks, the air, and
the oceans are part of Gaia. Gaia, as we shall see, has continuity with the past
back to the origins of life, and extends into the future as long as life persists.
Gaia, as a planet sized entity, has properties that are not necessarily discernible
by just knowing individual species or populations of organisms living together.
(Lovelock, 1995: 21)
Lovelock suggests that many people may find it hard to believe that anything as
large and inanimate as the Earth is actually alive. After all, most of it is rock and
the centre is extremely hot. However, he argues that one way to understand Gaia
is to think of a giant redwood tree. It is certainly alive, although about 99 per cent
of it is quite possibly dead. The giant redwood is an ancient column of dead wood,
composed of lignin and cellulose derived from layers and layers of cells built up
over a long time. The tree is thus analogous to the Earth, particularly when we
realize that many of the atoms of the rocks deep down in the magma were once
part of the ancestral life from which we have all evolved. More recently, in
The
Revenge of Gaia
(2006), Lovelock has continued to generate considerable controversy
