Changes In The Earth


Changes In The Earth’s Environment Essay, Research Paper

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


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


?… 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.


Brenton, T. (1994). The Greening of Machiavelli: The History of International

Environmental Politics. Earthscan Publications, London.

Burton, I., Kates, R.W. and White,G.F. (1978). The Environment as Hazard. Oxford

Uni. Press. New York..

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.

Heathcote and B.G. Thom (eds): Natural Hazards in Australia. 3-12, Australian

Academy of Science, Canberra.

Kevies, D.J. (1992). Some Like it Hot. New York Review of Books. 39:31-39.

McCall, G.J.H. (1992). Natural and Man Made Hazards: Their Increasing Importance

in the End 20th Century World in G.J.H.McCall, D.J.C.Laming and S.C.Scott (eds):

Geohazards: Natural and Man Made. 1-4, Chapman and Hall, London.

McKibben,B. (1990). The End of Nature. Penguin, Middlesex.

Meyer, W.R. and Turner, B.L. (1995). The Earth Transformed: Trends, Trajectories

and Patterns in R.J. Johnson, P.J. Taylor and M.J.Watts (eds): Geographies of

Global Change. 302-317, Blackwell, Oxford.

Pearce, D. (1995). Blueprint 4: Capturing Environmental Value. Oxford Uni. Press,

New York.

Perry,A.H. (1981). Environmental Hazards in the British Isles. Allen and Unwin.


Schnieder, S.H. (1989). Global Warming: Are We Entering The Greenhouse Century ?.

Sierra Club Books, New York.

Stow, D.A.V. (1992). Preface in G.J.H.McCall, D.J.C.Laming and S.C.Scott (eds):

Geohazards: Natural and Man Made. i-ii, Chapman and Hall, London.

Suzuki,D. and Gordon, A. (1990). It’s a Matter of Survival. Harvard Uni Press,


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