CAUSES AND EFFECTS OF “GREEN HOUSE” CONDITIONS
ON THE EARTH SURFACE
Yazar :
Okan YARDIMCI
The atmosphere is a mixture of several gases, the most significant among them are: oxygen, which is necessary for the metabolism of living organisms; nitrogen that forms essential compounds for the vegetation growth; carbon dioxide for the photosynthesis; and the water whose atmospheric cycle defines the various climates.
The smallest components of the mixture can change the natural composition of atmosphere, and therefore they can affect the atmosphere-biosphere balance. The ozone layer locate 20 Km in the atmosphere filtrate the most energetic UV radiation from the sun which is deleterious for life in this planet.
The emission of gases into the atmosphere produced from industrial activities, agriculture, cattle, domestic and mobile sourer used for transportation, among other causes, are accelerating the climatic change through the green house effect and ozone depletion. As a consequence, animal and plant species disappear and also human health is affected. The most alarming fact is the increasing rate at which these processes are developing in contrast with our indifference.
The greenhouse effect, is a warming of the Earth's surface and lower atmosphere that tends to intensify with an increase in atmospheric carbon dioxide. The atmosphere allows a large percentage of the rays of visible light from the Sun to reach the Earth's surface and heat it.
A simplified explanation of green house effects is as follows.
Shortwave solar radiation can pass through the clear atmosphere relatively unimpeded, but longwave infrared radiation emitted by the warm surface of the Earth is absorbed partially and then re-emitted by a number of trace gases--particularly water vapor and carbon dioxide--in the cooler atmosphere above.
Because, on average, the outgoing infrared radiation balances the incoming solar radiation, both the atmosphere and the surface will be warmer than they would be without the greenhouse gases.
This effect is due to certain gases in the atmosphere which are very good at absorbing the heat energy before it is lost to space. These gases, called "greenhouse gases" include carbon dioxide, water vapor, and methane. Without the greenhouse effect, the entire planet would be much colder, by about 63 degrees Fahrenheit (35 degrees Celsius), than it presently is.
Greenhouse Gases
The major gases in the atmosphere, nitrogen and oxygen, are transparent to both the radiation incoming from the sun and the radiation outgoing from the Earth, so they have little or no effect on the greenhouse warming.
The gases that are not transparent are water vapor, ozone, carbon dioxide, methane, nitrous oxide, and the chlorofluorocarbons (CFCs). These are the greenhouse gases.
There has been about a 25% increase in carbon dioxide in the atmosphere from 270 or 280 parts per million 250 years ago, to approximately 350 parts per million today.
What about the other effects of Green House conditions;
The greenhouse effect on Earth may be intensified and long-term climatic changes may result. An increase in atmospheric concentrations of other trace gases such as chlorofluorocarbons (Freons), nitrous oxide, and methane, due again largely to human activity, may also aggravate greenhouse conditions. A growing number of scientists have predicted that significant alterations in climate patterns will be seen by the turn of the century.
Such a global warming would probably bring other, sometimes deleterious, changes in climate; for example, changes in precipitation, storm patterns, and the level of the oceans.
Global warming ; the gradual increase in planet-wide temperatures -- seems to be accepted by many scientists and people now as fact. Generally, this warming is attributed to the increase of greenhouse gases in the Earth's upper atmosphere. However, some solar scientists are considering whether the warming exists at all. And, if it does, might it be caused, wholly or in part, by a periodic but small increase in the Sun's energy output.
What is the evidence for global warming? Certainly, there are considerably more green-house gases (e.g. carbon dioxide) in our atmosphere than in previous times. And there appears to be some evidence that global temperatures are increasing. But, how accurate and correct are our global warming statistics? And, do we really know what role, if any, the Sun might play in any global warming patterns?
There are some evidences for the role of the sun in climate change. For example the warming has occurred mostly at night and not during the day.
In short, some evidences shows us the warming can be consistent with problems in the surface network.
NASA has some investigations about Greenhouse Effect. Over the past 30 years, a number of satellite missions have been launched to obtain the data about Earth's radiation budget that are critical to understanding the greenhouse effect.
After a period, the greenhouse effect will become a definite.
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