The Greenhouse Effect








The Greenhouse Effect



















Issue Statement

While some people believe the earth\'s climatic changes are due to the fact that the
universe is getting older, others believe it is due to the greenhouse effect.


The greenhouse effect is a naturally occuring phenomenon that is responsible for trapping heat near the earth\'s surface and keeping the planet warm. It is called the greenhouse effect because the way it works is similar to the way in which a green house functions. In a greenhouse sunlight passes through the transparent roof and walls and strikes the objects inside- plants, flowerpots, tables, and so forth. These objects absorb energy from sun, become warmer, and then give off energy themselves in the form of heat. Only a little of this heat energy passes out through the glass, much of it is "trapped" in the greenhouse, raising the temperature inside.
In some ways, the earth functions rather like a greenhouse except on a much larger scale.
Although the greenhouse effect has only recently been in the news, is nothing new in th history of our planet, has played major role in making life on earth possible. Without the greenhouse effect, the earth would be too cold for living thing to survive. The big question today is "If greenhouse effect is natural, why are people so worried about it. Is soemthing good turning bad?" Up until about 150 years ago the compostion of the earths atmosphere had remianed relatively unchanged for several thousand years. Since mid 1800s certain human activities have been changing the heat trappin ability of the atmospher dramatically, as a result more heat is being trapped by the atmosphere. Scientists have been anticipating this "strengthening" of the greenhouse effect for sometime, and that it will lead to a worldwide increase in temperature. This is come true because the world is getting warmer. Global warming can be expected to change the earth\'s climate dramatically and in a relatively short time. As temperatures increase, experts predict that weather patterns will be disrupted worldwide, the glaciers and polar ice caps will, melt, and that sea levels will rise. Global warming could change the atmosphere so much and so fast that all sorts of plants and animals might soon be in danger os extinction. The greenhouse effect may be the most serious environmental problem the human race has ever experienced, for this reason scientists around the world are working hard to acheive a better understanding of the greenhouse effect, to predict the impact it will have on earth, and to discover ways to control it.
The greenhouse effect occurs when gases such as methane, carbon dioxide, nitrogen oxide and CFCS trap heat in the atmosphere by acting as a pane of glass in a car. The ‘glass\' lets the sunlight in to make heat, but when the heat tries to escape, the gases reabsorb it. Holding this heat in causes heat waves, droughts and climatic changes which could alter our way of living. The greenhouse effect, in environmental science, is a popular term for the effect that certain variable constituents of the Earth\'s lower atmosphere have on surface temperatures. "It has been known since 1896 that the Earth has been warmed by a blanket of gases. The gases; water vapour (H2O), carbon dioxide (CO2), and methane (CH4) keep ground temperatures at a global average of about 15 degrees C." (Oppenheimer, p. 119-120) Without them, the average would be below the freezing point of water. The gases have this effect because as incoming solar radiation strikes the surface, the surface gives off infrared radiation, or heat, that the gases trap and keep near ground level. Environmental scientists are concerned that changes in the variable contents of the atmosphere, particularly changes caused by human activities, could cause the Earth\'s surface to warm up to a dangerous degree. "Since 1850 there has been a mean rise in global temperature of approximately 1 degree C." (Gribbin, p. 14) Even a limited rise in average surface temperature might lead to at least partial melting of the polar icecaps and hence a major rise in sea level, along with other severe environmental disturbances.
What is meant by the term, the greenhouse effect, is that the heat from the sun comes into the Earth\'s atmosphere and cannot get out so it becomes trapped. This