Changes in the Earth’s EnvironmentThe 20th century, especially in the second half, has been one of rapidchange in the Earth’s environment. The impact of humans on the physical form andfunctioning of the Earth have reached levels that are global in character, andhave done so at an increasingly mounting speed. 20 years ago the environment wasseen as posing a threat to the future of humanity as death rates from naturalhazards had increased dramatically since the turn of the century.
The Earththough has always been plagued by natural disasters. Now, with the worldpopulation growing at a rapid rate more people are living in hazard prone areas.Events which may have gone unnoticed previously, only become hazards when thereis intervention with humans and their lifestyle.
With the discovery of the ozonehole in the 1980’s attention was now more focused on the threat humans wereposing to the environment. With scientific evidence to back up pessimisticpredictions of our future, most people, through media coverage, politicalpressures and general concern now see the environment as being truly threatenedby human progress and in desperate need of help.Natural hazards have been defined as .
..extreme geophysical events greatlyexceeding normal human expectations in terms of their magnitude or frequency andcausing significant damage to man and his works with possible loss of life.(Heathcote,1979,p.3.). A natural hazard occurs when there is an interactionbetween a system of human resource management and extreme or rare naturalphenomena (Chapman,1994). As McCall, Laming and Scott (1991) argue, strictlyspeaking there is no hazard unless humans are affected in some way.
Yet the linebetween natural and human-made hazards is a finely drawn one and usuallyoverlapping. Doornkamp ( cited in McCall et al, 1992) argues that many hazardsare 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 wasincreasing in frequency at quite a rapid rate (Burton, Kates, White, 1978).During the 75 years after 1900 the population of the earth increased by astaggering 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 largernumbers than before. The predominant movement of people being from farm to townor 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 andwere seen to pose such a threat to humankind in the 70’s. While the averagenumber of disasters remained relatively constant at about 30 per year, deathrates climbed significantly.As the growing world population requires the cultivation of land more proneto hazards, more people and property are thus exposed to the risk of disasterthan ever before, and as Stow (1992) argues, the death toll inevitably rises. Anexample that shows the concern that humans faced from the environment can beexemplified by the Bangladesh cyclone of 1970, which killed approximately250,000 people. Although part of the reason for so many deaths can be put downto a then poorly understood process, land-use can also be implicated. Because ofa rising population, land in Bangladesh was reclaimed by the government and heldagainst 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 wasinevitable Burton et al (1978) argue whenever population was in the path of suchforces. Had reasonable measures been taken in advance of the storm, the materialdamage, loss of life and social dislocation could have been seriously reduced.In the 1990’s we live in an information age.
Today we have remarkablemonitoring and predictive capabilities for natural hazards. The use of advancedtelecommunications and emergency management, together with the exploitation ofgeographic information systems in hazard mitigation has greatly reduced theextent 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 disasterscontinue to rise though as the population of the world rises and puts moredemands on the environment for land resources. White (1974) argues thatenvironmental risk may be considered to be primarily a function of the valuesystems of a society.
How dangerous a natural hazard is, is