Active Nitrogen and Global Warming
Fengrong Wang
Nowadays, due to the fact that people have gradually realized increased temperature may
cause various kinds of adverse results, more and more attention has been paid to investigate the
reasons that may lead to global warming. Active nitrogen is one possible explanation, a little
known but important factor. The following is possible reasons why active nitrogen can bring
about global warming.
1. Why temperature increasing:
Picture authorized by Climate Change Coordinating Unit, SamsenNai Phaya Thai Bangkok
Our earth gets heat from infrared radiation of the sun. Earth is enclosed by the atmosphere,
which functions as a coat of earth– trapping heat. Since the atmosphere is transparent to visible
light, the bulk of solar energy is released. But the atmosphere can absorb radiation in the infrared
range. Some substances in the atmosphere play the role of absorbents. They are cloud droplets,
water vapor, carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, and chlorofluorocarbons. The
atmosphere absorbs infrared radiation but also re-emit infrared radiation. When absorbing and
releasing reaches equilibrium, earth can keep its temperature at a certain point. This is an
essential condition that makes life on earth possible. If the infrared radiation generated by
atmosphere is less than the sum it absorbed, the built balance will be disrupted, therefore
temperature going up.
2. green-house effect gas:
Not all kinds of gases can absorb infrared radiation significantly. According to the principle
of infrared, In order to absorb infrared radiation, a molecular vibration must cause a change in
the dipole moment of the molecule (Dipole is a separation of positive and negative charge.)
Thus, common gases, such as O2, N2 and H2, their one-bond-symmetric vibration cannot create
a change in the dipole moment, so they could not absorb or emit infrared radiation.
Pictured authorized by Janice Gorzynski Smith
Although CO2 has symmetric structure, it can vibrate in six different ways - symmetrical and
asymmetrical stretching, scissoring, rocking, wagging and twisting. The last five vibrations
except symmetric stretch can lead to changes in dipole moment.
Picture authorized by Dr David J McGarvey, Keele University
Active nitrogen, such as NH3, NO2, NO, their bonds vibrations lead to change in dipole
moment so that they will absorb infrared radiation, producing green-house effect, whereas due
to one-bond-symmetric vibration, inavtive nitrogen, N2, cannot bring out any change in dipole
moment. This is why active nitrogen instead of inactive nitrogen may cause global warming.
3. nitrogen source:
N- fixing bacteria/plants
Marine environments
Lighting
Human sources
100Tg/yr
5-20Tg/yr
10Tg/yr
130Tg/yr
Figure by the McGraw-Hill Companies
Figure suplied by Michael Pidwirny depicting the nitrogen cycle
Natural sources of active nitrogen include oceans, tropical soils, wet forests, dry savannas,
and extra-tropical forests. Human sources contain nitrogen fertilizers usage, biomass burning
and other combustion processes, and acid production processes. Accoring to the above figure ,
nitrogen fixation by humans now exceeds nonhuman sources. Natural removal processes are
incapable stemming this increase. When increased amount of active nitrogen go in to the
atmosphere through nitrogen circulation presented below, they absorb more infrared radiation,
contributing to global warming.
Green house gases can occur naurally or as a result of human activities. It is difficult to
label it with just one of them. Human beings cannot conquer and manipulate nature. Global
warming may be one punishment given by nature because of human’s abusive usage of energy
and natural resources. We could not change the way nature goes, but we could regulate the way
we are going. Global warming have already made some people homeless through elevating the
level of the sea. Actually, its adverse effects are far from that. Starvation, diseases, wars may
also be the possible results. Before it goes to far, feasible ways must be made to combat it.
Maybe we can start from reducing the emission of greenhouse gases.