Global Change & Global Warming In recent years, scientists have become increasi

The greenhouse effect, also known as global warming, is caused by various gases which get trapped in the earth's atmosphere. Some of these gases, such as methane, are caused by the decomposition of organic matter. However, the worst greenhouse gases are those which are caused by human beings. These include carbon dioxide and nitrous oxide resulting from the burning of fossil fuels, and chlorofluorocarbons resulting from the use of aerosol sprays and refrigeration systems. Under normal conditions, much of the infrared energy of the sun bounces off the earth and reflects back into outer space. However, when these gases accumulate in the earth's stratosphere, the energy from the sun is trapped near the earth's surface (4:131). As a result, the earth's temperature is increased. This increase in temperature has a powerful effect on climate, as well as raising sea levels around the world.

Some of the pollutants in the air are also causing the depletion of the earth's ozone layer. Normally, the ozone layer shields plants and animals from the ultraviolet rays

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even death for certain people with medical conditions (2:75). Other health hazards can result from the depletion of the ozone layer. For example, direct exposure to the sun's ultraviolet rays can cause skin cancer, cataracts, or problems with the immune system (3:113). These problems can have a negative impact on food crops, as well. In fact, there is the threat that global pollution might damage the entire food chain. This could occur because excessive ultraviolet radiation has a tendency to kill the oceanic plankton which at the base of that chain (2:12). The loss of animal and plant species in the rain forests is another detrimental factor in global change. A number of unique species live in the world's rain forests, and their loss represents a vital loss in terms of scientific research. In addition, many of those species are an important source for medicines (4:334). It has been noted that, once a forest area is cleared, the unique species that lived in the environment are usually lost forever (3:116). Another threat to the ecosystem which is caused by global change is that of rising sea levels. Because of global warming, an increased amount of ice will melt into the oceans, thereby raising sea levels. In additio
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Approximate Word count = 1222
Approximate Pages = 5 (250 words per page)