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Stáhnout celý tento materiálGlobal problems of the world
Population growth
The increase in population means that more pollution is generated, more natural resources are used up and more natural habitats are destroyed.
It seems that the most important factors to slow down population growth may be democracy and social justice. Women can make their own reproduction choices and birth control information is more widely available.
Global warming
Certain gases in the Earth´s atmosphere cause process called the greenhouse effect. The gases, primarily carbon dioxide, let the sun´s radiation through to heat the Earth´s surface. But because of these gases part of the energy, which is radiated back out into the space, can´t escape. Without the greenhouse effect, uor planet would be much cooler that it is now.
Nowadays the concentrations of these gases in the atmosphere increase, which means that the temperatures all over the world will rise.
The consequences of increase in temperature would be devastating. The sea levels would rise, many tropical deseases would expand, nomerous of species would die out. Deserts can be created in some areas and the frequency of hurricanes would also increase.
Depletion of the ozone layer
The ozone layer is the thin layer in the atmosphere. It protects the Earth´s surface from the sun´s harmful ultraviolet rays (paprsky). But the layer was being dissolved (rozkládána) by the chemicals used in air-conditioning systems or refrigeration.
The consequences of ozone layer depletion are for example increase in cases of skin cancer or reduction of the ability of people´s immune syste
Vloženo: 1.09.2011
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