what is greenhouse effect? which gases are responsible for it
Answers
Explanation:
The gaseous mantle around our globe allows a considerable portion of solar radiations to enter right upto the surface of earth which absorbs it and radiates back infra-red and heat waves. This heat is transferred to layers above, as warm layer rises and is in turn passed on to higher and higher layers. Finally much of the solar radiations are radiated back to space as infra-red and heat waves.
The system consisting of our globe and its atmosphere is in a state of dynamic equilibrium with the rate of absorption of solar radiations and its emission back to space as infra-red and heat waves, nearly balancing each other. Those gases and vapours which allow free passage to radiations of relatively shorter wavelengths (2900 A – 7000 A) while absorbing effectively infra-red and heat waves (700 A onwards) play a very important role in maintaining surface temperatures within a range in which life can exist.
They form a blanket around the globe which checks the passage of infra-red and heat waves from earth’s crust back to space and keep it warm and hospitable. The phenomenon is similar to that of green-house in which the glass enclosed atmosphere gets heated up due to its insulation from the rest of the environment. Hence, global warming is also known as Green House effect and the gases responsible for it are called green house gases.
There are a number of gases present in the atmosphere which are capable of absorbing effectively heat waves and infra-red rays while being transparent to radiations of lower wavelengths. Carbon dioxide, methane, oxides of nitrogen, sulphur dioxide, ozone, chlorofluorocarbons and water vapours are some of the gaseous constituents of troposphere which come in this category.
From the point of global warming, however, only those gases are important which maintain an effective concentration in the troposphere, i.e., the region of atmosphere immediately covering earth’s surface. There are five such gases rising concentration of which has been implicated in causing noticeable rise in the mean global temperatures. These gases are: carbon dioxide, methane, chlorofluorocarbons, nitrogen oxide and water vapours. Other gases like sulphur dioxide, ozone are not able to contribute much; they are quickly cleared from the atmosphere.
The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without this atmosphere.
The gasses are water vapor, 36–70%
carbon dioxide, 9–26%
methane, 4–9%
ozone, 3–7%
It is not possible to assign a specific percentage to each gas because the absorption and emission bands of the gases overlap (hence the ranges given above). Please mark my answer as brainiest.