Carbon, Phosphorus, and Nitrogen Cycles - Essay Example

When the animals and plants die and they decompose, carbon atoms are returned back to the atmosphere, and the cycle starts again. Humans have the ability to negatively impact the carbon cycle. The most common method of doing this is by burning any type of fossil fuel, including oil, coal, and natural gas. When fossil fuels are burned, CO2 is produced and released into the atmosphere. While breathing CO2 is a normal part of the carbon cycle, when humans create more CO2 than oxygen-producing plants cannot keep up with, the cycle is thrown off (Wigley, 2000).

In a similar sense, humans are also impacting the carbon cycle by cutting down plants, trees, and whole forests, further ridding ourselves of one of the aspects of the carbon cycle, as well as a vital component of oxygen production. The phosphorus cycle is a biogeochemical cycle that takes place as phosphorus moves through the lithosphere, hydrosphere, and biosphere. Phosphorus is found in rocks and begins as phosphate ions. When it rains, the phosphate ions are removed from the rocks and are distributed into the soil and water.

From there, plants absorb the phosphorus compounds from the soil, then animals take up the phosphorus atoms when they eat the plants. These phosphorus atoms are also found in water, where plants can absorb the water or animals can take a drink. When phosphorus is in the water, it gradually accumulates over time into insoluble deposits (Cole, 1999), which will be released back onto land as rocks, prompting the cycle to go again. Humans can impact the phosphorus cycle by creating too much phosphorus in the environment.

When humans use fertilizers or pesticides, which are heavy in phosphorus atoms, they move the phosphorus around and it becomes excess runoff. As runoff, the phosphorus can end up in large bodies of water, which can lead to eutrophication, killing animals and plants that rely on that body of water. Also, sewage treatment facilities that use lakes and rivers as dumping grounds create phosphate pollution that can grow algae and cyanobacteria, which destroys the oxygen in the water and reduces species diversity.

The nitrogen cycle is the process in which nitrogen makes its way through nature. Nitrogen is an essential element for life; humans do not use the nitrogen, but it is still vital for our bodies. When plants and animals die, they decompose and add nitrogen into the soil. Bacteria within the soil converts the nitrogen into a form of nitrogen that plants are able to use to help themselves grow (Bothe, 2007). Animals and people eat the plants, obtaining their source of nitrogen. The animals and plants decompose and return nitrogen back into the soil.

The cycle then repeats itself. Humans can impact the nitrogen cycle by producing too much nitrogen. They are capable of doing this through the pollution emitted by vehicles and chemical plants, doubling the amount of annual transfer of nitrogen into biologically-available forms (Howarth, 2006), as well as by force-feeding plants nitrogen through nitrogen-containing fertilizers. Humans can also impact the nitrogen cycle by depleting the amount of nitrogen that is made accessible. This can be done by the dumping of sewage and other types of organic matter into bodies of water, which damages oxygen levels, thus damaging nitrogen supplies.

References Bothe, H. (2007). Biology of the nitrogen cycle.