Why is Air Pollution a Global Problem?

Scientists have estimated that every day, an average person inhales about 20,000 liters of air.  Every time we breathe, we risk inhaling dangerous chemicals that have found their way into the air. Air pollution includes all contaminants found in the atmosphere.  These dangerous substances can be either in the form of gases or particles. Air pollution can be found both outdoors and indoors.  Pollutants can be trapped inside buildings, causing indoor pollution that lasts for a long time. The sources of air pollution are both natural and human-based.  As one might expect, humans have been producing increasing amounts of pollutants as time has progressed, and they now account for the majority of pollutants released into the air.

Air pollution has been a problem throughout history.  Even in Ancient Rome people complained about smoke put into the atmosphere. The effects of air pollution are diverse and numerous.  Air pollution can have serious consequences for the health of human beings, and also severely affects natural ecosystems. Because it is located in the atmosphere, air pollution is able to travel far off places easily.  As a result, air pollution is a global problem and has been the subject of both global cooperation and conflict. Some areas now suffer more than others from air pollution.  Cities with large numbers of automobiles or those that use great quantities of coal often suffer most severely from problems of air pollution.

 Ancient Greek and Roman thoughts began the environmental sciences.  Major philosophers advanced differing views that affected others and shield their views for years to come. The early Greeks searched for a reasonable understanding of nature.  The ideas they developed influenced Europe in the future. Thales of Miletus, the founder of the Ionian school, was the initiator of Greek philosophy on the environmental sciences.  The Ionian school hoped to discover the nature of the universe, and how it came about.  According to Thales, everything was composed of water and the combination of the sun and water was the source of life.

Empedocles (c.493-c.433 BC) argued that the universe was composed of four elements: earth, air, fire, and water, which combined in different ways and proportions to produce different results and products. In his Memorabilia, the Greek writer, Xenophon (c.428-c.354 BC) contends that the planet earth exists for people and the climate of the earth, and the living creatures on it, are for the benefit of humanity.  Xenophon says ‘The earth was created by a god for people.’ His work later influenced Christianity. In Rome, Cicero (106-43 BC) wrote that nature should be controlled by humans.  According to him the earth was designed for humanity, as was each different species. 

In respect of the theory of the four elements, the Greek philosopher Aristotle (384-322 BC) added a fifth one: the heavens.  After breaking with Plato (429-347 BC), Aristotle thoroughly investigated the natural world.  He thought that the earth could be divided into sections defined by the amount of heat each received, and that people could only live in the more inhabitable areas. Aristotle accepted the theory that underground wind caused volcanoes and earthquakes.  He understood the origins of rivers and believed in a pattern of rainfall. Teleology, which explained things in terms of their purpose, was a major part of Aristotle's theory.  It caused him to heavily research reproduction. Aristotle's Historian Animalium details over 500 species, examining common characteristics between the species. Throughout the ancient periods, interest in botany grew because of its relation to medicine.  Many philosophers advanced varying theories that would affect Europe in later years.

Today, there are a vast number of environmental problems, all with unique causes and consequences.  Some people have said that Christianity is one of the primary causes of the degradation of the environment. Lynn White has said that the modern destruction of the environment can be attributed to Christianity. According to White the Biblical belief that nature, seen as inferior to people, can be controlled by man, has brought a lack of respect for the sacredness of the environment. White would also argue that Christianity is greatly responsible for the advent of Western science and technology.  Modern technology has clearly been one of the main sources of environmental difficulties.

The Judeo-Christian notion of nature is that it is not sacred like God.  Man, however, is believed by this group to be made in God's image, and can therefore shape nature as God would. There are some who would disagree with this application of Christianity.  Those who believe in "stewardship" would say that people must respect and not destroy nature, not overexploit natural resources, and allow other animals to live in nature as well. Many important theological thinkers would agree with this version of Christianity.  Calvin said that man is the steward of God's earth, and has no right to exploit and destroy it.  Also, St. Thomas Aquinas said that man had some responsibility towards animals. Christianity also favors the environment in some respects.  To the benefit of the environment, the religion encourages caring for other people, including those of the future, and some level of respect for the environment.

There are many different chemical substances that contribute to air pollution.  These chemicals come from a variety of sources. Among the many types of air pollutants are nitrogen oxides, carbon monoxides, and organic compounds that can evaporate and enter the atmosphere. Air pollutants have sources that are both natural and human.  Now, humans contribute substantially more to the air pollution problem. Forest fires, volcanic eruptions, wind erosion, pollen dispersal, evaporation of organic compounds, and natural radioactivity are all among the natural causes of air pollution.

Usually, natural air pollution does not occur in abundance in particular locations.  The pollution is spread around throughout the world, and as a result, poses many threats. Though some pollution comes from these natural sources, most pollution is the result of human activity.  The biggest causes are the use of fuels in power plants and automobiles that combust fuel.  Combined, these two sources are responsible for about 90% of all air pollution in the United States. Some cities suffer severely because of heavy industrial use of chemicals that cause air pollution.  Places like Mexico City and Sao Paulo have some of the most deadly pollution levels in the world.

Air pollution is responsible for major health effects.  Every year, the health of countless people is ruined or endangered by air pollution. Many different chemicals in the air affect the human body in negative and destructive ways.  Just how sick people will get depends on what chemicals they are exposed to, in what concentrations, and for how long. Studies have estimated that the number of people killed annually in the US alone due to environmental pollution-related diseases could be over 50,000. Older people are highly vulnerable to diseases induced by air pollution.  Those with heart or lung disorders are under additional risk.  Children and infants are also at serious risk. Because people are exposed to so many potentially dangerous pollutants, it is often hard to know exactly which pollutants are responsible for causing sickness.  Also, because a mixture of different pollutants can intensify sickness, it is often difficult to isolate those pollutants that are at fault.

Many diseases could be caused by air pollution without their becoming apparent for a long time.  Diseases such as bronchitis, lung cancer, and heart disease may all eventually appear in people exposed to air pollution. Air pollutants such as ozone, nitrogen oxides, and sulfur dioxide also have harmful effects on vital systems.  They can kill plants and trees by destroying their leaves, and can kill animals, especially fish in highly polluted rivers. Air pollution has many disastrous effects that need to be checked and curbed prudently.  In order to accomplish this, scientists, environmentalists, and governments, are using or testing a variety of methods aimed at reducing pollution. There are two main types of pollution control. Input control involves preventing a problem before it occurs, or at least limiting the effects the process will produce. Five major input control methods exist. 

Output control, the opposite method, seeks to fix the problems caused by air pollution.  This usually means cleaning up an area that has been damaged by pollution. Input controls are usually more effective than output controls.  Output controls are also more expensive, making them less desirable to tax payers and polluting industries. Current air pollution control efforts are not all highly effective.  In wealthier countries, industries are often able to shift to methods that decrease air pollution.  In the United States, for example, air pollution control laws have been successful in stopping air pollution levels from rising.  However, in developing countries and even in countries where pollution is strictly regulated, much more needs to be done.

Over the past years, human energy consumption has risen dramatically.  The rise in use of energy resources has meant increasing costs and the depletion of non-renewable supplies.  These and other factors have led people to try to use energy in a more efficient manner. The First Law of Thermodynamics says that energy can be transferred between forms, but not created or destroyed.  The Second Law of Thermodynamics says that usage of heat to perform work inevitably causes some heat to be lost to the surrounding environment.  As a result, perfect efficiency in energy use is impossible.

For many things and devices that use energy, a maximum efficiency limit exists.  A four-cycle internal combustion engine can achieve at most 54% efficiency, while a diesel engine can reach 56%.  Steam engines only perform at 32% efficiency.  In reality, engines are considerably worse than this due to designs that prevent achievement of maximum efficiency. If one includes all devices that use energy, about 85% of energy in the US is lost due to inefficient usage. Many low-efficiency devices exist because when they were developed, energy costs were very low.  Only later, when energy costs rose, did it make sense to be more energy efficient.

Devices that increase efficiency often are priced higher than those that perform inefficiently.  However, because less energy is used and the devices often last longer (such as fluorescent light bulbs), the efficient devices are sometimes cheaper in the long run. Governments are trying to promote efficient energy use for the sake of our future and their future generations who may be deprived by us of chances to generate air pollutants.