Geoscience Reference
In-Depth Information
In many ways, the early work of Blaikie on the
social dimensions of soil erosion is remembered for
bringing political and economic considerations
into the scientific analysis of land degradation. But
the notion of political ecology developed by Blaikie
is as much about bringing nature into the work of
social scientists as it is about bringing a human
perspective into studies of nature.
droughts caused by significant reductions in
precipitation were seen by many to be the major
cause of soil erosion. In addition to drought
conditions, long periods of high winds were also
seen by physical scientists to be major contributory
factors within soil degradation episodes. Thomas
(1993) has taken scientific understandings of the
nature of soil erosion (and desertification) a step
further. Thomas argues that estimates of human-
induced soil erosion have been significantly
overestimated, with a significant amount of what
is described as desertification actually being the
product of the natural fluctuation in dryland
vegetation levels. Second, from a Malthusian
perspective, soil erosion was associated with the
pressures of overpopulation, which forced farmers
and landholders to overwork their land in order
to feed the expanding population (for more on
Malthusian perspectives see
Chapter 2)
. Third, and
finally, soil erosion was seen as the product of
bad decision-making on the part of farmers and
landholders. On these terms, soil degradation was
interpreted as the outcome of farmers either being
4.3.2 Beyond nature and the
individual
Having located the origins of political ecology
within the pioneering work of Piers Blaikie, let us
consider precisely what this perspective can
contribute to our understanding of soil erosion.
Before the emergence of political ecology, soil
erosion was predominantly understood in three
broad ways. First, and from the perspective of the
physical sciences, soil erosion was interpreted as a
natural phenomenon that, even when exacerbated
by human activity, was largely driven by processes
of physical environmental change. On these terms,
In a 1993 article in the Geographical Journal, the geographer David Thomas questioned established
estimates and interpretations of desertification throughout the world. At the heart of Thomas's
analysis is the belief that studies had started to confuse the natural fluctuations that exist in the spread
and contraction of deserts (driven by changing rainfall levels and associated patterns of vegetation
coverage) with human-induced soil erosion. According to Thomas, the conflation of these two
processes resulted in vast overestimates of the rates of anthropogenic desertification. In order to
ensure that better estimates of anthropogenic desertification are achieved in the future, Thomas
argues that the notion of desertification should only be used in reference to dryland environments
and where land degradation is not part of a natural ecological cycle. This more restricted
understanding of desertification is important because it makes a distinction between human-induced
soil erosion and the natural geographical spread and contraction of deserts. Thomas's work does
not suggest that soil erosion is not a major global problem, but simply that it is not necessarily
connected to the migration of desert fronts.
Key reading
Thomas, D.S.G. (1993) 'Sandstorm in a teacup? Understanding desertification', Geographical Journal 159:
318-331
