Air Pollution and Ecological Perspectives of the Atmosphere

Introduction

CO₂ transmits sunlight efficiently to earth but restricts and traps a portion of the infrared radiation bouncing back into space. If the balance between the CO₂ levels in the ocean and atmosphere is disturbed by interjecting increasing amounts of CO₂, the oceans would continually absorb higher concentrations than it does naturally. The subsequent warming ocean waters are less effective in their ability to absorb CO₂ and when the oceans can no lonager keep pace with the intrusion of this naturally equalized cycle, then more CO₂ will remain in the atmosphere.

“Currently carbon dioxide is responsible for 57 percent of the global warming trend. Nitrogen oxides contribute most of the atmospheric contaminants” (Miller, 1990, p. 498). Increasing the amount of CO₂ in the atmosphere through human activity causes a warming of the Earth’s surface accelerating the greenhouse effect.

Main body

The rising levels of carbon dioxide (CO₂) in the atmosphere are becoming increasingly disconcerting. “The concentrations of CO₂ in the air around 1860 before the effects of industrialization were felt, is assumed to have been about 290 parts per million (ppm). In the hundred years and more since then, the concentration has increased by about 30 to 35 ppm that is by 10 percent” (Breuer, 1980, p. 67). The major contributors to CO₂, one of the main pollutants in the atmosphere, are the burning of fossil fuels and deforestation.

Eighty percent of the world’s population accounts for just 35 percent of CO₂ emissions while the United States and Soviet Union combined are responsible for generating half. Worldwide, “carbon dioxide emissions are increasing by four percent a year” (Miller, 1990, p. 450). Motor vehicles are a major cause of air pollution as is fuel burned for the heating of homes and powering industry and toxins emitted from stacks at coal-burning power plants. “Vehicles produce high levels of carbon monoxides (CO) and a major source of hydrocarbons (HC) and nitrogen oxides (NOx), whereas, fuel combustion in stationary sources is the dominant source of sulfur dioxide (SO₂)” (Breuer, 1980, p. 70).

Smog, a contraction of the words smoke and fog, is a chemical air pollutant that contributes to the greenhouse effect and is a significant health hazard to those in U.S. cities that contain numerous vehicles and are located in warm, dry climates as it traps in these dangerous chemicals. The effects of air pollution are far-reaching and cannot be escaped by staying inside the home as indoor air pollution can be harmful, caused by such things as poor ventilation, mold and microbe-harboring air conditioning systems and ducts. The Environmental Protection Agency (EPA) reports that “toxic chemicals found in the air of almost every American home are three times more likely to cause some type of cancer than outdoor air pollutants” (Miller, 1990, p. 488).

While the world awaits the inevitable far-reaching effects associated with greenhouse gas emissions, people’s lungs are being poisoned as the plants they depend on for near-term survival are being destroyed. “In the Midwestern United States crop losses of wheat, corn, soybeans, and peanuts from damage by ozone and acid deposition amount to about $5 billion a year” (Miller, 1990, p. 498). Pollutants such as sulfur dioxide and nitrogen oxides cause immediate and irreparable damage to the leaf pores of plants and trees. Persistent exposure of leaves to air pollutants breaks down the waxy coating which normally acts to prevent too much water loss and helps protects the leaves from diseases, pests, drought and frost.

Insects such as the bark beetle, currently killing off large portions of the northern pine forests, benefit tremendously from the increased CO2 levels as they are typically only capable of infesting weakened trees. “Bark beetle populations often remain at low densities for long periods of time, during which they colonize only highly stressed trees. Droughts, windstorms, and other environmental disturbances, however, can suddenly increase the availability of weakened hosts, causing beetle populations to rise dramatically” (Raffa & Barryman, 1987: 236). Overpopulation of beneficial or slightly damaging herbivorous creatures such as these can lead to highly destructive behaviors if not kept in check.

Conclusion

It is clear that something needs to be done about the chemicals we, as a species, are dumping into the air we depend on for life. If the population of the planet were to immediately discontinue polluting the air with carbon dioxide emissions, climate changes would still continue long into the future. This is “because of the long lifetimes of carbon dioxide (centuries) and other greenhouse gases in the atmosphere and because of the thermal inertia of the oceans. The oceans overturn very slowly and take hundreds of years to adjust fully to changes, so that manifestations of changes that have already occurred are not yet fully seen” (Trenberth 1997).

There are, fortunately, several possibilities by which we might address the issue. Increased attention and support for alternative renewable energy sources is an important first step. Reducing the number of combustion engines on the roads as well as the extent of power supply plants dumping pollutants into the air as more and more energy-producing houses feed into the grids rather than pull from them would all contribute toward a better, brighter, cleaner tomorrow.

Works Cited

Breuer, Georg. Air in Danger: Ecological Perspectives of the Atmosphere. New York: Cambridge University Press, 1980.

Miller, G. Tyler. Living in the Environment: An Introduction to Environmental Science. Belmont: Wadsworth, 1990.

Raffa, Kenneth F. & Berryman, Alan A. “Interacting Selective Pressures in Conifer-Bark Beetle Systems: A Basis for Reciprocal Adaptations?” The American Naturalist. Vol. 129, N. 2, (1987), pp. 234-262.

Trenberth, Kevin E. “Global Warming: It’s Happening.” National Center for Atmospheric Research. (1997). Web.