critical thinking paper

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Total Word Count: 550

Cascading Effect of Nitrogen and its Environmental Impact

Introduction (53 words)

While nitrogen in the natural state is not harmful, excess amounts of the reactive form will

pollute the air, waterways, and ecosystems. The rise of human activity involved in the production

of nitrogen has caused this to become an environmental problem, and more steps should be taken

to understand and reduce its impact.

Analysis (424 words)

Nitrogen is an essential nutrient in biological lifeforms and is natural to the environment. The

supply of nitrogen was limited to natural sources until the Haber-Bosch process was developed,

which then gave rise to high demand and economic interests to produce nitrogen and its many

forms. Agriculture, energy use, and land use doubled the amount of reactive nitrogen since the

1940s (Liu et al., 2014; p. 625). Reactive nitrogen is all forms of nitrogen except the inert state

that is common in breathable air. It is in the excess of the reactive forms of nitrogen that is

threatening to air and water quality, as well as various environmental ecosystems relying on the

water cycle (Liu et al., 2014; p. 625).

The limited amounts of nitrogen available naturally has caused the world’s ecosystems to adapt

to re-use essential nitrogen molecules in a closed nitrogen cycle. The agriculture, energy

production, and the transportation industry has introduced more reactive nitrogen, such as nitrous

oxide and ammonia, to the environment with nitrogen oxides as an unintentional waste product

(Erisman et al., 2013; p. 2). Reactive nitrogen quickly dissipates to the environment and cascades

through the air and water but will naturally convert back to inert N2. Human production of

reactive nitrogen, however, outpaces the natural conversion back to its natural state which leads

to excess accumulation in the ecosystem (Erisman et al.,2013; p. 2).

The environmental effects include acid rain and nitrogen deposition, which contributes to the

acidification of water and soil while also upsetting the nutrient balance of the local ecosystem

(Galloway et al. 2013; p. 7). Excess nitrogen will affect the nitrogen-sensitive species and hinder

plant growth, cascading that problem by saturating the nitrogen. In the water, excess can impact

algae growth which in turn cause eutrophication, or pollution caused by excessive nutrients

(Galloway et al. 2013; p. 7).

Perhaps most importantly, nitrogen’s role in atmospheric conditions is understated, as nitrous

oxide (N2O) is the largest known threat to the ozone layer that still remains and contributes to

climate change and ozone layer depletion (Kanter et al., 2012; p 4451). Nitrous oxide emissions

in the atmosphere oxidizes into nitric oxide and coupled with nitrogen oxides form the catalyst

which contribute to ozone depletion (Kanter et al., 2012; p 4453).

Nitrogen can easily change into many chemical forms, each of which can impact the

environment differently. (Kanter et al., 2012; p 4456). As such, humans need to reduce it impact,

as its global use is expected to increase 1.4% each year, according to the FAO (2015; n.p.)

Evaluation (46 words)

There is clear bias. One report is funded by the EPA, while others are affiliated with

environmental organizations. Their work shows a clear concern for the potential threat of

nitrogen; the full extent of its impact is still unclear as stated by two of the authors.

Conclusion (27 words)

Reactive nitrogen has a cascading effect which impacts the environment on many levels. Steps

should be taken to reduce its impact before its full impact is realized.

Bibliography

Erisman, Jan Willem, et al. “Consequences of Human Modification of the Global Nitrogen

Cycle.” Philosophical Transactions: Biological Sciences, vol. 368, no. 1621, 2013, pp.

1–9. JSTOR.

Food and Agricultural Organization of the United Nations. 2015. “Fertilizer Use to Surpass 200

Million Tonnes in 2018.” International Rice Commission Newsletter Vol. 48, FAO of the

UN, 2015, www.fao.org/news/story/en/item/277488/icode/. Accessed 15 November

2018.

Galloway, James N., et al. “A Chronology of Human Understanding of the Nitrogen Cycle.”

Philosophical Transactions: Biological Sciences, vol. 368, no. 1621, 2013, pp. 1–11.

JSTOR.

Liu, Chen, et al. “Socioeconomic Driving Factors of Nitrogen Load from Food Consumption and

Preventive Measures.” Ambio, vol. 43, no. 5, 2014, pp. 625–633.

Kanter, David, et al. “A Post-Kyoto Partner: Considering the Stratospheric Ozone Regime as a

Tool to Manage Nitrous Oxide.” Proceedings of the National Academy of Sciences of the

United States of America, vol. 110, no. 12, 2013, pp. 4451–4457. JSTOR.