Tag: carbon cycle

The warming up of the atmosphere due to trapped radiation is called green house effect. Green house gases like carbon dioxide, methane, nitrous oxide etc; increase in green house gases leads to global  warming.

When solar radiation enters the atmosphere, it is absorbed by the clouds and gases and heats the earth's surface. The earth, in return, reflects some of this heat into the atmosphere as infrared radiation. Most of this infrared radiation gets absorbed by atmospheric gases such as carbon dioxide, methane, nitrous oxide, and ozone, commonly known as greenhouse gases. These gases send the infrared radiation back to the earth's surface, thereby heating the surface again. This cycle repeats several times, thereby resulting in the greenhouse effect.

(The greenhouse effect is the natural process by which the atmosphere traps some of the Sun's energy,  warming the Earth enough to support life.  Most mainstream scientists believe a human-driven increase in "greenhouse gases" is increasing the effect artificially.
These gases include carbon dioxide, methane, nitrous oxide, water vapour, CFCs, ozone etc. Ozone in the stratosphere acts as a protective layer, but harmful if it is present in the troposphere).

A national CDM (clean development mechanism) authority has set up in December 2003 to formulate projects for reducing emission of CO$ _2$ and other green house gases. 

Solar radiation is absorbed in the Earth's surface and emitted as thermal energy that can be re-absorbed by greenhouse gases. Greenhouse gases include water vapor, carbon dioxide, ozone, and methane; the major components of atmospheric gas nitrogen, oxygen, and argon are transparent to infrared radiation. The greenhouse effect insulates the earth's surface, making it hospitable to life; however, human activities have increased the concentration of these gases, causing global warming.

Greenhouse gases are called so because they are capable of absorbing the insolation from the sun and keeping it within the troposphere, thereby increasing the overall temperature of the earth, called global warming. Carbon dioxide, methane, nitrous oxide, ozone, Chlorofluorocarbons and sulphur hexafluoride are considered to be the potent greenhouse gases. Oxygen is not a greenhouse gas.

The gases in the troposphere of the atmosphere absorb the sun radiations and trap them so that they do not reflect back. This process allows the heat to remain trapped with in the atmosphere and the earth surface remains warm. This process is called greenhouse effect and the absorbed radiations striking the earth's surface are called green house flux. Carbon dioxide, water vapour, oxides of nitrogen are useful for this purpose. 

A greenhouse gas absorb radiation and emit heat energy maintaining the Earth's temperature. However, when released in excess amounts, they cause global warming. Sources are volcanic eruptions, burning of fossil fuels, deforestation, vehicular exhausts, industrial emissions etc. contribute to the greenhouse gases. Carbon dioxide, Chlorinated hydrocarbon (CHC), Methane and oxides of nitrogen are considered to be the major greenhouse gases.