It occurs naturally in the form of potassium nitrate, saltpeter, and sodium nitrate, chile saltpeter, in its mineral deposits. So, Is Nitrogen a greenhouse gas? The answer is “NO”!!! Nitrogen is not a greenhouse gas as it does not interact with the infrared radiations of the sun and hence, is infrared inactive and does not participate in maintaining the temperature inside the earth’s atmosphere. Nitrogen in its other forms such as nitrous oxide contributes as a greenhouse gas. Let us read out till last for detailed information. Stay connected!!  

Why is Nitrogen not a Greenhouse gas?

In a molecule, a chemical bond can be regarded as a spring that has one nucleus attached to each end. The distance between these nuclei increases and decreases with the vibration of the bond that occurs due to the oscillation of the nuclei. This results in the development of an electromagnetic field for a molecule which makes a molecule visible to the infrared radiations of the sun. The molecules that are detectable by the radiations are known as infrared active while those that are not discernible are known as infrared inactive. In the atmosphere, the gases that are infrared active can act as greenhouse gases. Nitrogen is the major gas in the atmosphere that constitutes about 78% of the gaseous component. It exists as a diatomic molecule i.e. N2. As two nitrogen atoms are connected on the two ends of a triple bond this is a symmetrical molecule. Due to this symmetry, the molecule is unable to create an electromagnetic field around it as the electric field developed by one atom is canceled due to the electric field of the corresponding atom of the same molecule connected on the opposite end of the chemical bond. Basically, no symmetrical gas molecule is able to behave like a greenhouse gas. As there is no electromagnetic field surrounding the nitrogen molecule due to its symmetrical structure, as a result, it is invisible to the infrared radiations reflected from the earth’s surface i.e. it is infrared inactive and is unable to work as a greenhouse gas.  

What is the Greenhouse effect?

The greenhouse effect is the process through which the heat coming from the sun through its infrared radiations is absorbed in the earth’s atmosphere. This effect is responsible for making the earth a habitable planet by maintaining the temperature within the range required by various living beings to thrive. Without the greenhouse effect, the temperature of the earth would be around -18 °C making it impossible for any life form to survive. The greenhouse effect results in heating of the earth’s surface as well as the atmospheric layer closest to its surface i.e. troposphere. It arises due to various gases present in the atmosphere that absorb infrared radiations from the sun and trap them to maintain the temperature of the earth suitable for sustaining different living beings.

How does this Greenhouse effect work?

Actually, the atmosphere of the earth allows most of the visible parts of sunlight to reach the earth’s surface which gets heated and reflects back some of the heat in the form of infrared radiation towards space. These infrared radiations have a longer wavelength in comparison to visible light rays and are, therefore, absorbed by various greenhouse gases present in the earth’s atmosphere. These radiations are then radiated back towards the surface of the earth, thus, resulting in heating of the surface as well as the atmosphere of the earth and altogether raising the overall temperature of the planet.  

Which gases are Greenhouse gases?

As discussed earlier the asymmetrical gas molecules are responsible for the greenhouse effect. Therefore, various gases such as carbon dioxide, methane, water vapors, etc. are known as greenhouse gases. As the molecules connected on either end of the chemical bond in these gases are different from each other, an electromagnetic field is developed due to which they become visible to the infrared radiations of the atmosphere absorbing these radiations resulting in elevating the temperature of the earth’s surface. Amongst different greenhouse gases, the percentage of contribution of different gases is different. The water vapors are the major contributors that are responsible for 36-70% of the greenhouse effect. Other than this carbon dioxide contribute about 9-26%, methane 4-9%, and ozone 3-7%.

A few other gases such as nitrous oxides, fluorinated gases, carbon monoxide, etc., are also present in the atmosphere, that are responsible for greenhouse effects but it is not possible to specify the percentage contribution for all the gases.  

How do Greenhouse gases cause Global Warming?

Global warming refers to the heating of the earth’s atmosphere observed since the pre-industrial period resulting in climate change due to human activities such as the burning of fossil fuels. It is estimated that since the pre-industrial period the temperature of the earth has increased about 1°C and is now increasing at an average rate of about 0.2°C per decade. The percentage of various gases in the atmosphere has varied extensively since the formation of the earth. The change in the concentration of the greenhouse gases in the atmosphere has resulted in serious climate changes at different timescales on the earth. The concentration of greenhouse gases in the atmosphere is affected by a number of processes such as the movement of tectonic plates, vegetation, wetlands, etc. Recently various human activities such as industrialization have resulted in the increase in the concentration of greenhouse gases in the atmosphere. The burning of fossil fuels has especially resulted in elevating the levels of carbon dioxide, methane, chlorofluorocarbons, etc. This increase in the concentration of greenhouse gases has resulted in an increase in the temperature of the earth.  

Global warming refers to the heating of the earth’s atmosphere observed since the pre-industrial period resulting in climate change due to human activities such as the burning of fossil fuels. It is estimated that since the pre-industrial period the temperature of the earth has increased about 1°C and is now increasing at an average rate of about 0.2°C per decade. A report released by Intergovernmental Panel on Climate Change (IPCC) has stated that there is a strong connection between human activities and global warming. Due to the increased temperature of the earth, a change has been recorded in weather patterns indicating that the natural balance of the planet is being disrupted. Increasing droughts, melting glaciers, rise in sea levels, ocean acidification, and other major climate changes are all results of global warming.  

Does Nitrogen contribute to Greenhouse gases?

Well! Not directly. As discussed in the first section of this article nitrogen exists as a diatomic symmetrical molecule that is invisible to infrared radiations and therefore, does not play any role as a greenhouse gas. However, nitrogen in its other forms such as nitrous oxide contributes as a strong greenhouse gas. It is estimated to be 300 times more effective as a greenhouse gas in comparison to carbon dioxide. Presently, oceans contribute about 25% of the total emission of nitrous oxide. Various researches indicate that certain oxygen minimum zones are serving as hotspots of nitrous oxide emission.  

Properties of Nitrogen

A few of the important properties of nitrogen are given in the table below:  

Uses of Nitrogen

Some of the important uses of nitrogen are listed below: • It is used as a substitute for argon in incandescent light bulbs. • Nitrogen is also utilized in the production of stainless steel. • It is used in the nitriding process used for case hardening of steel. • Liquid nitrogen is used in the cryopreservation of biological materials. • For aerosol cans, nitrogen is used as propellant gas. • It is used in welding, soldering, and brazing metals.    

Conclusion

Nitrogen is not a greenhouse gas as it does not absorb infrared radiation and thus, has no role in maintaining the temperature of the earth. Nitrogen is infrared inactive as it exists as a diatomic molecule that has identical atoms on both ends of the chemical bond due to which the electric field generated by one atom is canceled by the other and in absence of an electromagnetic field the molecule is not recognized by the infrared waves. The visible rays of the sun fall on the surface of the earth which absorbs these rays and then reflects them back towards space in form of a larger wavelength as infrared waves. These infrared radiations are trapped by the greenhouse gases and then again reflected back towards the earth’s surface resulting in the rise of temperature. This entire process is known as global warming. Some of the important greenhouse gases present in the earth’s atmosphere are water vapors, carbon dioxide, methane, ozone, etc. Excessive emission of greenhouse gases as a result of industrialization has resulted in the rise of the earth’s temperature beyond normal which has caused severe climate changes posing a threat for coming years.

Is Nitrogen a Greenhouse Gas  - 81Is Nitrogen a Greenhouse Gas  - 64