Geoscience Reference
In-Depth Information
The subject called 'physical geography' was once taught to general students in
many universities. Now it is almost an endangered species; few institutions still have
geography departments, and the average contemporary undergraduate - even those
studying scientifi c subjects - would be unable to say what is encompassed by the
subject.
For those concerned with the vital matter of environmental quality, physical geog-
raphy is a core discipline. It attends to the structure and character of the local and the
global habitat: landforms, temperature, soils, and climate. It examines the way in which
those physical factors determine the pattern of occupancy by living systems - that is,
it seeks explanations for the spatial distribution of species of organisms, and of the
development, through their interactions, of ecosystems. Finally, it attempts to explain
how humans have settled on the land and have used it. Dressed up in a more modern
name, physical geography is Earth systems science. (Kennedy, 2000, p. 13)
Notwithstanding the explicit borrowing of general systems theory during the
quantitative revolution of the 1960s and 1970s, such claims about the intellectual
debts of ESS to physical geography do not withstand scrutiny. As an example,
Chorley and Kennedy (1971, pp. 82-93) discuss the 'solar energy cascade', which
can be seen as a direct parallel to the bicameral atmosphere-biogeochemical
cycles approach of ESS. Figure 10.3 illustrates this division very clearly. However,
this version of the model is focused on the energy and water components - largely
in order to make specifi c predictions about catchment hydrology. It contains
little in the way of biogeochemical linkages with the atmosphere. Such concerns
did not feature much in physical geography before the 1990s. One reason,
perhaps, was the increasing reductionism of research in physical geography from
the 1970s onwards, often with an aim related to environmental management;
ESS aimed explicitly to be holistic, to develop understanding, and thus, to guide
policy.
The best interpretation is probably one of parallel development from similar
backgrounds. Chorley was well aware of the climate-modelling literature (the fi rst
edition of Atmosphere, Weather and Climate written with Roger Barry was pub-
lished in 1968), while Bretherton was director of the US National Center for Atmo-
spheric Research (NCAR) from 1974. Climate modelling was part of the NCAR
remit from its inception in 1959 (UCAR, 1959) and experience with overseeing the
development of the NCAR climate model had a strong infl uence on Bretherton ( pers.
comm. ).
This idea of a holistic approach is part of the underlying rationale for ESS:
Though the specifi c requirements differ in each case, rational treatment of each such
issue [of environmental change] depends on an understanding of many different com-
ponents of the global environment and the interactions between them, and appreciation
of the functioning of the system as a whole. This fundamental knowledge, rather than
the isolated issues themselves, is what consititutes Earth System Science (Bretherton,
1985, pp. 1118-9).
Clifford and Richards (2005) criticise this outward holism of ESS. They use com-
plexity theory to suggest that there are many ecosystem features that cannot be
accounted for in terms of energetics or biogeochemistry. While undoubtedly true of
the original structure of ESS, it is not clear that this critique applies universally.
Indeed, many ecological models working within the complexity theory remit do deal
Search WWH ::




Custom Search