The concept of Green House Effect





          There is no denying the fact that Green House Effect is warming up of earth's atmosphere due to the trapping of infra-red radiation reflected from the earth's surface by the carbon dioxide layer in the atmosphere is called green-house effect. The green-house effect in the atmosphere occurs due to the presence of a blanket of carbon-dioxide gas in the atmosphere. This blanket of carbon dioxide gas in the atmosphere allows the sunlight to come in freely but does not allow the infra-red radiation reflected by the earth's surface to go out. It is just because the sun light can come in freely but the intra-red rays cannot go out freely that the temperature of earth's atmosphere is raised. The rise in temperature produce gas in the by green-house effect on earth's atmosphere depends on the amount of carbon dioxide gas in the atmosphere. In other words, the proportion of carbon dioxide in atmosphere effects the temperature of atmosphere. So, if the proportion of carbon dioxide gas in the atmosphere increases, than the temperature of earth's atmosphere will also rise further.

 The name "Green-house effect" comes from the fact that this effect is use in horticulture for the upbringing of green plant's in small house made of glass walls and glass root. The green walls and roofs of a green-house allows the sun-light to come in freely but it does not allows the long wavelength infrared radiations reflected by the soil, plants and other contents of greenhouse to go out. These trapped intra-red rays show their heating effect due to which the temperature is raised inside the green house. Thus, even without an external supply of heat, the temperature inside a green house is found to be higher than it is outside. Thus, green house acts as a heat trap. Due to the presence of carbon dioxide, our atmosphere acts like the glass rat of an ordinary horticultural green-house. Carbon dioxide (CO2) is an atmospheric constituent that plays several vital roles in the environment. It absorbs infrared radiation in the atmosphere. It plays a crucial role in the weathering of rocks. It is the raw material for photosynthesis and its carbon is incorporated into organic matter in the biosphere and may eventually be stored in the Earth as fossil fuels.

It is a significant fact that most of the sun's energy that falls on the Earth's surface is in the visible light portion of the electromagnetic spectrum. This is in large part because the Earth's atmosphere is transparent to these wave lengths as we are conversant that with a functioning ozone layer, the higher frequencies like ultraviolet are mostly screened out. In this respect part of the sunlight is reflected back into space, depending on the reflectivity of the surface. And another part of the sunlight is absorbed by the Earth and held as thermal energy. This heat is then re-radiated in the form of longer wavelength infrared radiation. While the dominant gases of the atmosphere (nitrogen and oxygen) are transparent to infrared, the so-called greenhouse gasses, primarily water vapor (H2O), CO2, and methane (CH4), absorb some of the infrared radiation. They collect this heat energy and hold it in the atmosphere, delaying its passage back out of the atmosphere.

 

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