Essay/Term paper: Changes in the earth's environment

Essay, term paper, research paper:  World History

Changes in the Earth's Environment


The 20th century, especially in the second half, has been one of rapid
change in the Earth's environment. The impact of humans on the physical form and
functioning of the Earth have reached levels that are global in character, and
have done so at an increasingly mounting speed. 20 years ago the environment was
seen as posing a threat to the future of humanity as death rates from natural
hazards had increased dramatically since the turn of the century. The Earth
though has always been plagued by natural disasters. Now, with the world
population growing at a rapid rate more people are living in hazard prone areas.
Events which may have gone unnoticed previously, only become hazards when there
is intervention with humans and their lifestyle. With the discovery of the ozone
hole in the 1980's attention was now more focused on the threat humans were
posing to the environment. With scientific evidence to back up pessimistic
predictions of our future, most people, through media coverage, political
pressures and general concern now see the environment as being truly threatened
by human progress and in desperate need of help.
Natural hazards have been defined as "...extreme geophysical events greatly
exceeding normal human expectations in terms of their magnitude or frequency and
causing significant damage to man and his works with possible loss of life."
(Heathcote,1979,p.3.). A natural hazard occurs when there is an interaction
between a system of human resource management and extreme or rare natural
phenomena (Chapman,1994). As McCall, Laming and Scott (1991) argue, strictly
speaking there is no hazard unless humans are affected in some way. Yet the line
between natural and human-made hazards is a finely drawn one and usually
overlapping. Doornkamp ( cited in McCall et al, 1992) argues that many hazards
are human induced or at least made worse by the intervention of humans.
In the 1970's, natural hazards were an important subject of topical study,
as the nature of their impact on human populations and what they valued was
increasing in frequency at quite a rapid rate (Burton, Kates, White, 1978).
During the 75 years after 1900 the population of the earth increased by a
staggering 2.25 billion people. People who needed land on which to live and work.
As the population rose people were dispersed in more places and in larger
numbers than before. The predominant movement of people being from farm to town
or city (Burton et al,1978.). It is this growing world population, Burton et al
(1978) suggest, that is the main reason behind why hazards are increasing and
were seen to pose such a threat to humankind in the 70's. While the average
number of disasters remained relatively constant at about 30 per year, death
rates climbed significantly.
As the growing world population requires the cultivation of land more prone
to hazards, more people and property are thus exposed to the risk of disaster
than ever before, and as Stow (1992) argues, the death toll inevitably rises. An
example that shows the concern that humans faced from the environment can be
exemplified by the Bangladesh cyclone of 1970, which killed approximately
250,000 people. Although part of the reason for so many deaths can be put down
to a then poorly understood process, land-use can also be implicated. Because of
a rising population, land in Bangladesh was reclaimed by the government and held
against the sea. People in large numbers were then encouraged to occupy the area.
An area which turned out to be one of great risk. Major disruption was
inevitable Burton et al (1978) argue whenever population was in the path of such
forces. Had reasonable measures been taken in advance of the storm, the material
damage, loss of life and social dislocation could have been seriously reduced.
In the 1990's we live in an information age. Today we have remarkable
monitoring and predictive capabilities for natural hazards. The use of advanced
telecommunications and emergency management, together with the exploitation of
geographic information systems in hazard mitigation has greatly reduced the
extent to which natural hazards are seen as a threat to people in the 90's
(Chapman et al, 1994). Loss of life and property from natural disasters
continue to rise though as the population of the world rises and puts more
demands on the environment for land resources. White (1974) argues that
environmental risk may be considered to be primarily a function of the value
systems of a society. How dangerous a natural hazard is, is not measured in
absolute terms but in how dangerous it is perceived to be. 20 years ago,
technology hadn't advanced to the level at which natural hazards could be
properly understood and prepared for (Perry,1981). Chapman (1994) argues that in
technologically advanced societies we have "...greatly accepted the hazards
inherent in the comforts of life that technology provides and learned to live
with hazards." (p.156).In the 1970's, using Heathcote's (1979) definition, "
"normal human expectations" were lower than they are today therefore causing
such concern for the environmental threat to humans.
20 years ago it was the spectacular, rapid onset, intensive hazards such as
earthquakes, volcanoes, cyclones and floods that caught the media headlines and
caused concern for the future of humankind from the environment. Today it is the
slow onset, pervasive hazards that have caught the attention of the whole world,
and in the long term pose more threat than the intensive hazards (Chapman,1994).
Space exploration has given us an awareness that it is human activity that is
contributing to this long term threat and the future of the planet as a whole
(McCall,1992).
It has been suggested that when the history of the 20th century is written,
environmentalism will be judged to be the single most important social movement
of the period (Brenton,1994). While the threat from humans to the environment
has been an issue for some time, the conflict has been sharpened by the
emergence of new concerns; ozone depletion, global warming, loss of biological
diversity and the destruction of the rainforests. Prior to the late 20th century
the main insults to the environment were evident, people could see smog and
pollution and notice animals missing from the forests. These new issues involve
a new type of danger to the environment (Suzuki,1990). Dangers which are much
less visible and often will not materialise for years to come. It is primarily
because of scientific predictions that we know about them and without science
would have probably gone largely unrecognised until it was too late for action
to be taken (McKibben,1989). These new dangers are ones that can be measured and
enumerated by scientists. The belief that the earth has been seriously damaged
and is being damaged more rapidly than ever before is a far more prevalent and
respectable belief than ever before. It is a belief that is growing in
popularity (Meyer and Turner,1995). Johnson, Tayor and Watts (1995) point out
that:

"... increasingly the assumption that the earth is being
improved requires a defence and an explanation, while
the assumption that it is being dangerously degraded
requires none." (p.304).

Coping with global environmental change has come to appear one of humankinds
most pressing problems.
Perhaps the most powerful representative of this new "global consciousness'
has been as Brenton (1994) suggests, the "Earthrise' photograph taken by the
Apollo II in 1969. As people are able to see the earth as a whole for the first
time, they are also able to see more clearly that which ecologists have always
stated, that everything on the earth is tied to everything else (Pearce,1995).
Since it's capture , the "earthrise' photograph has been extensively exploited
by exponents of the "fragile planet' view of the human experience. Between 1970
and 1990 global population rose from 3.7 billion to approximately 5.3 billion
people. Energy consumption grew even faster, while nuclear production of
electricity rose twentyfold. The number of vehicles more than doubled and by the
early 1990's people were consuming about 40% of the entire global "natural
product' from the photosynthesis of plants (Brenton,1994). Tropical rainforests
have been devastated and the productivity of more than 1.2 million hectares of
land has been lowered by human activities. 20% of the CO2 in the atmosphere has
been put there by humans, largely through C.F.C production, and it has been
C.F.C's that have created one of the most disturbing changes to the environment,
that of the discovery of the hole in the ozone layer and the theory of global
warming (McKibben,1987).
Ozone is a molecule of oxygen, made up of three oxygen atoms and it's
existence is essential for many life supporting systems. Ozone occurs at two
levels in the atmosphere; the stratosphere and the troposphere. In the
stratosphere it is concentrated into the "ozone layer', and it is this
concentration that protects the earth from U.V radiation from the sun, taking
out 90% of U.V rays. It's depletion was first recognised in 1985, when a gaping
hole was found over Antarctica. By 1989 it became clear that C.F.C's and halons
were indisputably implicated in the collapse over Antarctica, that ozone had
diminished over heavily populated areas of the world and that further
significant depletion would occur if extreme action was not taken to stop ozone-
depleting substances (Kevies,1992).
Apprehension of global warming on the other hand, rests on the theory that
high concentrations of CO2 in the atmosphere trap radiation reflected from the
earth, creating a "greenhouse effect'. This then leads to an increase in
temperature in the region close to the planets surface. The current attention
given to the climatic impacts of CO2 owes much to the weather of the 1980's
(Schnieder,1989). The 80's were already the warmest on record, when the hot
spring and summer of 1988 came along, bringing with it drought, crop disasters
and fire hazards. Suddenly the "greenhouse effect' was given major consideration
by Press front pages, T.V networks, celebrity benefits and in political circles.
Schnieder (1989) notes that in 1988, nature did more for the notoriety of global
warming in 15 weeks than anyone else was able to do for the previous 15 years.
How much of this warming is due to an increase in CO2 though and what the actual
consequences will be is a debatable subject (Pearce,1995). Although climatic
change is occuring, why it's occuring is not known for certain. Pearce (1995)
argues though, that even if the science of global warming turns out to be
incorrect, it is not worth the risk to do nothing about it. McKibben (1990)
declares that to doubt that the warming will happen because it hasn't yet
appeared is"... like arguing that a woman hasn't yet given birth and therefore
isn't pregnant." (p.12).
As the 20th century draws to a close, a general awareness is spreading
around the globe that human activity can and is causing serious damage to the
environment. Slogans such as "think locally,act globally' and "the earth is one
but the world is not' adhere to the principal that, everything is tied to
everything else. Problems on land become problems at sea and in the environment.
Humans now realise that it is they that pose the threat to the environment,
rather than the environment being a threat to humanity. The danger is shining
through the sky, with overwhelming evidence that the earths ozone layer is being
destroyed by human-made chemicals far faster than any scientist had predicted.
The threat is no longer just to the future, the threat is here and now.

References

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Burton, I., Kates, R.W. and White,G.F. (1978). The Environment as Hazard. Oxford
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Chapman, D.M. (1994). Natural Hazards. Oxford Uni. Press, New York.

Heathcote, R.L. (1979). The Threat from Natural Hazards In Australia in R.L.
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Suzuki,D. and Gordon, A. (1990). It's a Matter of Survival. Harvard Uni Press,
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