Environmental Engineering Reference
In-Depth Information
even have cumulative effects which could
threaten the survival of human species. Although
the idea of the earth as a living organism is a
basic concept in Gaia, the hypothesis is not
anthropocentric. Humans are simply one of the
many forms of life in the biosphere, and whatever
happens life will continue to exist, but it may
not be human life. For example, Gaia includes
mechanisms capable of bringing about the
extinction of those organisms which adversely
affect the system (Lovelock 1986). Since the
human species is currently the source of most
environmental deterioration, the partial or
complete removal of mankind might be Gaia's
natural answer to the earth's current problems.
The need for coexistence between people and
the other elements of the environment, now being
advocated by Lovelock as a result of his research
into Gaia, has been accepted by several
generations of geographers, but historically
society has tended to view itself as being in
conflict with the environment. Many primitive
groups may have enjoyed a considerable rapport
with their environment, but, for the most part,
the relationship was an antagonistic one
(Murphey 1973; Smith 1992). The environment
was viewed as hostile, and successful growth or
development depended upon fighting it, and
winning. In the beginning, human inputs were
relatively minor, and the results of victory could
easily be accommodated in the system. Gradually,
through technological advancement and,
sometimes sheer weight of numbers, society
became increasingly able to challenge its
environment and eventually to dominate it.
Natural vegetation was replaced by cultivated
crops, rivers were dammed or diverted, natural
resources were dug from the earth in such
quantity that people began to rival
geomorphological processes as agents of
landscape change, and, to meet the need for
shelter, nature was replaced with the built
environment created by urbanization.
The environment can no longer be considered
predominantly natural in most of Europe and
North America. Technological innovations since
the mid-eighteenth century have ensured that. In
the less-developed nations of Asia, Africa and
South America—where the impact of technology
is less strong—pressure from large and rapidly
growing populations has placed an obviously
human imprint on the landscape. Extensive as it
is, however, dominance is far from complete.
Even after 200 years of technological
development and the exponential growth of
population in recent years, some geographical
regions continue to resist human domination. The
frozen reaches of the Arctic and Antarctic are
not unaffected by human activity, but they are
largely unpopulated, while habitation in the
world's hot deserts is in all senses marginal.
HUMAN ACTIVITIES AND THE
ATMOSPHERIC ENVIRONMENT
Certain elements in the environment remain
untamed, uncontrollable and imperfectly
understood. Nowhere is this more evident than
in the realm of weather and climate. Neither
nineteenth nor twentieth century technology
could prevent cyclones from devastating the
shores of the Bay of Bengal, or hurricanes from
laying waste the Caribbean. The Sahelian
drought spread uncontrollably even as the first
astronauts were landing on the moon. The
developed nations, where society's dominance of
the environment is furthest advanced, continue
to suffer the depredation of tornadoes and
blizzards as well as the effects of less spectacular
weather events such as frost, drought, heatwaves
and electrical storms, which even today are
difficult to forecast. No one is immune.
It is scarcely surprising, therefore, that weather
and climate are universal topics of interest at all
levels of society. In most cases, concern centres
on the impact of short-lived local weather events
on individuals and their activities. It is very much
one-sided, normally ignoring the potential that
mankind has to alter its atmospheric
environment. There is a growing appreciation,
however, that the nature and extent of the
climatological component in many current global
issues is strongly influenced by human
interference in the earth/atmosphere system. The
