Laughing Gas

Abstract

A Laughing gas (chemically known as nitrous oxide) becomong a potential threat to our environment, appears to be a mind-boggling truth, N₂O<i> </i>is not only a potential greenhouse gas, but also implicated in the catalytic destruction of stratospheric ozone layer, which saves us from onslaught of UV-B radiation from the sun. Although its atmospheric concertration, as compared to CO₂ and CH₄, is very low (310 ppbv), its contribution to greenhouse effect is

measured to be 6%, based on high thermal absorption capacity and long residence time in the atmosphere. The thermal absorption of N₂O<i> </i>was estimated to be 150 times higher than CO₂ and 5 times higher than CH₄. Being a highly non-reactive gas in the troposphere, it moves uniterrupted to the stratosphere to cause damage to ozone layer.<br>

Among the various anthropogenic sources, agriculture is the major contributor to N₂O<i> </i>emission because of high intensification of farming supplemented with the high input of N-chemical fertilizers. According to IPCC (1992)] the cultivated soils alone contribute 0.03-3.0 Tg N-N₂)/yr, which is about 20% of total N₂O<i> </i>emission to the atmosphere. N₂O is produced in both oxic and partial anoxic conditions by nitrifying and denitrifying bacteria, respectively, and transported to the atmosphere mainly through molecular diffusion and partially through aerenchyma of plants. Its emission to the atmosphere is considered as a colossal loss of N-input to the farming.