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.
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. London.
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, Harvard.