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from soils into surrounding river systems and
eventually the oceans. In rivers and oceans artificial
fertilizers no longer support the growth of food
crops but are instead absorbed by phytoplankton
(more commonly referred to as microalgae). In
warmer climates (particularly in springtime) the
flow of nitrogen and phosphorous into the oceans
can prompt the growth of huge algae blooms (see
Plate 4.2)
. In the worse cases, these blooms can be
so thick that they prevent light reaching the sea
floor, creating 'dead zones' within the ocean.
The adding of nitrogen to soils represents one
of the key ways that humans have been shifting
the operation of global environmental systems
during the Anthropocene. The forcing of the
nitrogen cycle now means that in European states
somewhere in the region of 70-75 per cent of all
nitrogen that is fixed in soils is now added through
artificial means (Dent et al, 2007: 100). The impacts
of the addition of these levels of nitrogen to the
global nitrogen cycle means that elevated levels of
nitrogen can now be detected in underground
aquifers and high-altitude clouds (Dent et al,
2007). The heighted presence of nitrogen in the
global environment not only results in harmful
algae blooms. When nitrogen is converted into
nitrous oxides it actively contributes to both the
erosion of the planet's ozone layer and to the
production of acid rains. Notwithstanding the
environmental problems that are associated
with the anthropogenic boosting of the nitrogen
cycle, large parts of the world now depend on
nitrogen fertilizers for their food supply. As with
so many problems that are associated with the
Anthropocene, there is thus no easy solution to
the current imbalance that we are seeing in the
nitrogen cycle.
4.3 INTERPRETING THE
TRANSFORMATION OF
SOIL: A POLITICAL
ECOLOGY PERSPECTIVE
So far this chapter has established the nature
and extent of contemporary patterns of soil
degradation and pollution. This section introduces
political ecology
as a framework within which we
can better understand our collective relations
with soil. Although notions of political ecology
developed specifically in the context of analyses of
land degradation, we see that the ideas presented
within this body of work have more general
application within the study of environmental
change in the Anthropocene.
4.3.1 Piers Blaikie and the early
political ecologists
As its name suggests, political ecology denotes a
field of study that is interested in the connections
that exist between social systems, biological
processes, technological change, ecosystems,
economic power and environmental transforma-
tion (see Bryant, 1998). While the term itself was
first coined in the 1930s, it started to be used more
widely during the 1970s (see Wolf, 1972). The
notion of a political ecology perspective - at least
as we understand it today - actually can be traced
back to a study of socio-economic development
in the Himalayan state of Nepal (see Simon, 2007:
699). The study was commissioned by the UK
government's Overseas Development Administra-
tion and carried out by the British academics Piers
Blaikie, John Cameron and David Seddon. The
final report of this study,
Nepal in Crisis
, deployed
a broadly Marxist perspective on the effects of
international development (Blaikie et al, 1980).
Dirt! The Movie
The recent documentary film Dirt! The
Movie
provides a helpful overview of
both the role of soil in supporting life
on Earth and the extent of the human
transformation of soil resources. See:
9h18nrN4
