Nitrous oxide- The world’s forgotten greenhouse gas

Nitrous oxide is a powerful greenhouse gas.

Nitrous oxide, also referred to as “laughing gas,” is the third most significant greenhouse gas, following methane and carbon dioxide, and poses the most critical risk to the ozone layer by humans.

It is 300x more potent than carbon dioxide. Nitrous oxide contributes to the greenhouse effect in the same way that carbon dioxide, by capturing infrared radiation that is emitted from the Earth’s surface and heating the atmosphere. It is inactive chemically in the troposphere and is within it for around 120 years before moving into the stratosphere, destroying the stratospheric air.

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The global biogeochemical cycle of nitrous oxide.

Scientists from the Intergovernmental Panel on Climate Change (IPCC) believe that nitrous oxide contributes to around 6 percent of greenhouse gases, and around three-quarters of N₂O emissions originate from agriculture. In the past century, the quantity of nitrogen oxide in our atmosphere has risen by 16 percent.

While the amount of nitrous oxide (N₂O) in the atmosphere isn’t huge, it’s the most significant of all greenhouse gases.

Why is laughing gas becoming a major environmental threat?

The emission of nitrogen oxide is increasing remarkably in the human body, most likely due to synthetic fertilizers and animal husbandry.

One N₂O molecule released into the air contributes nearly 300 times more to the climate than one carbon dioxide molecule (CO₂). Although the N2O released by soil isn’t much, it still plays an essential role in climate change.

It also degrades the Ozone layer. Scientists from the Intergovernmental Panel on Climate Change (IPCC) believe that nitrous oxide contributes to around 6 percent of greenhouse gas emissions and that about three-quarters of the emissions of N₂O come from agriculture.

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Ozone depleting by nitrous oxide

Yet, despite its crucial impact on climate change, N₂O emissions are often ignored in climate policy. A 2020 study of N₂O sources and emissions loss found that the latter are up by 30 percent in the last four years and are higher than even the most advanced models presented by IPCC.

“We put a lot of emphasis on nitrogen oxide because it stays in the atmosphere for a long time — usually a century or more after it’s released.”


Emissions of nitrous oxide

The primary source of nitrogen oxides is agriculture, particularly fertilized soils and animal waste, making it difficult to control. Global N₂O emissions are rising due to human activities that increase the production of N₂O.

The gas known as Nitrous Oxide (N₂O) can be described as a powerful greenhouse gas created by microbes living in the soil.

Natural sources

The quantity of nitrous oxide created by natural sources is controlled by natural sinks and has been doing so for hundreds of years. Before human intervention, the N₂O levels weren’t constant because of this balance in nature.

1. Oceans

Oceans are responsible for around 25 percent of the world’s N₂O emissions. The ocean’s warming due to climate change fuels the development of the world’s most oxygen-deficient water bodies. It has been a source of speculation that N₂O emissions from oceans will continue to increase and increase the rate of climate change.

Globally, oceans are believed to add around three million tonnes of nitrogen Oxide-N into the atmosphere yearly. Similar to methane, the majority of Nitrous oxide that occurs in surface seawater comes from the activities of microorganisms within the vicinity of sinking materials like fecal granules. These particles provide anaerobic conditions required to nitrify, a process that generates the nitrous oxide that is a byproduct.

2. Soils that are under natural vegetation

Soil microorganisms create nitric oxide through denitrification and nitrification. The emission of N₂O by soils under natural vegetation is significantly affected by the type of plant as well as the organic content of the soil and soil pH, compaction, and evaporation. However, soil C and plants are the major sources of N₂O emission.

Denitrification and nitrification of microorganisms help in the natural disposal and storage of around 70% of all N₂O emissions.

Human-caused sources

Human activities producing nitrogen oxide have increased by 30% over the past four years. These sources account for 77% of the human emission of nitrogen oxide.

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Agriculture, particularly fertilized soil and animal waste, accounts for about three quarters of U.S. nitrous oxide emissions.

1. Targeting Fertilizers and Agriculture

Agriculture accounts for 16 to 27% of global warming emissions due to different soil management activities in the agricultural sector, like the application of organic and synthetic fertilizers, as well as other farming practices, such as manure management or burning agricultural residues. These practices generate Nitrogen oxide (N₂O) in the primary source.

The agricultural sector is responsible for 60% of the N₂O emission in this state. Particularly nitrogen fertilization practices influence the production of N2O since fertilizers enhance the supply of NH₃/NH4⁺ to nitrify microbes and NO₃ to Nitrifiers.

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Bacteria use the nitrogen in fertilizers to produce nitrous oxide

The emissions of N₂O increase significantly when the amount of fertilization is greater than the consumption of crops. It is essential to be careful about fertilization overuse.

2. Fuel combustion.

Nitrous oxide is released as fuel is burned. The amount of N₂O released when burning fuel varies based on the fuel used, the combustion technology, and the maintenance and operation.

The most significant cause of nitrogen dioxide from human activities is fuel combustion (coal gas, oil, and coal), especially the gasoline used in automobiles.

Combustion creates N₂O on solid water and smoke because these fuels have nitrogen bound by their molecular structures. Nitrogen bound to fuels converted to N₂O at the proper temperature. In the case of hot combustion, N₂O begins to appear early in the flame when the nitrogen content is high.

3. Industries.

The second most significant source of N₂O comes from the Chemical industry, and experts believe emissions can be cut significantly and at a low cost. Nitrous oxide is made as a byproduct in the manufacturing of chemicals like nitric acids, which are utilized to produce synthetic fertilizers that are commercially available, as well as adipic acids, that is used to make fibers such as nylon and various other items.

It is also made through the manufacture of Nitric acid, welding using explosives, refining metals, and petroleum commercial industries, as well as in the food industry.

To cut down on N₂O emissions, chemical plants are incredibly efficient and economical technology that is in use. A process that uses catalysts converts the gas into oxygen and pure nitrogen and reduces emissions by as much as 90 percent.

Another option is to place an air dehumidifier near the end of the pipe feeding the plant. It removes about 99 percent of N₂O through the burning process.

4. Animal manure

The emission of nitrogenous oxide during fertilization occurs during the decomposition process of nitrogen sources under anoxic conditions. N₂O and methane also influence the place of manure treatment within zones of climate and the length of manure removal. The most significant elements are oxygen availability and temperature, humidity, pH, and soil management, which convert nitrogen into nitric oxide.

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Nitrite accumulation enhances the N₂O emission

Globally related to livestock, NOₓ emits thought at between 1 and 2 million tonnes of NOₓ-N each year.

For instance, using underground wastewater injections may result in lower levels of nitrogen oxide than applied to open pastures.

The most effective ways to cut down or eliminate N2O emissions

  • Drip systems are more focused than pre-irrigation systems in providing nutrients and water (through fertilization) to the crop’s roots. It reduces the duration and the area in which conditions that boost N₂O production happen.
  • Nitrification inhibitors are chemical substances that stop ammonia oxidation within the soil, producing N₂O by denitrification and nitrification.
  • Using pre-planted soil can reduce the soil’s inorganic N, leading to less N available to be converted into N₂O.
  • Modifying the kind of fertilizer used could influence the emissions of N₂O. Ammonia anhydrous (AA) is an adequate supply of N than fertilizers based on urea and may raise the pH of soils, which can lead to an increase in soil nitrite and production.
  • Utilize separate applications of nitrogen fertilizer. It improves plants’ efficiency, meaning less nitrogen loss into the atmosphere or leaks out. This method is ideal in areas with flooding.

Final thoughts

The growing greenhouse effect is due to the increase in radiation intensity that results in a rise in greenhouse gas emissions generated by human activity. The gas nitrous oxide (N₂O) as carbon dioxide is a gas with a long life that is a greenhouse gas and accumulates throughout the Earth. There are a variety of effective techniques to cut down on N₂O emissions.

Author: Mahvish ShamimHi, I am Mahvish Shamim. A chemist, and content writer. I love working with WordPress and doing it the right way. Also passionate about spreading awareness about the environmental crisis. Through my skills, I will deliver high-quality work.

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