When discussing overpopulation, its impact on the environment is the most discussed issue. While there is little debate that human population increase erodes the environment, there is a fierce debate on the impact of human numbers alone. Again, human choices affect the environment as much as sheer numbers. The debate about just how much human numbers affect the environment has long historical roots. Thomas Malthus, whose "Essay on the Principal of Population" was first published in 1798, began a debate which continues 200 years later. Malthus warned the human race was doomed because the Earth's finite resources could not support unlimited geometric population increases. Contemporary biologist Paul Ehrlich proposes population growth must be halted to avoid worldwide ecological disaster in his best seller The Population Bomb.
Since 1950, the world's population has doubled, and its economic output has increased almost fivefold. In that time, world water use, and demands for grain, firewood, beef and mutton have tripled, and fossil fuel use has nearly quadrupled. If human population is successfully limited to 12 billion, the problem of meeting human needs isn't solved. At current yields, over 3 billion hectares of arable land would be required to feed 12 billion people, and while there are 3.3 billion hectares of potentially arable land available on Earth, the economic and ecological cost of bringing it all into production is prohibitive. An effort to bring 3 billion hectares under cultivation implies an enormous loss of habitat for many entire species and for the critically important wild varieties of human food species.
There is substantial evidence of environmental destruction here in the United States. Depletion of soil, water, and fuel at a much faster rate than any of these can be replenished suggests that the carrying capacity of the United States already has been exceeded The disappearance of natural capital is continuing at a great rate and is compromising future food production. Iowa has lost 50 percent of its topsoil since the advent of farming in the nineteenth century. The drawdown of U.S. aquifers is also proceeding quickly and, so far, has led to abandonment of over 300,000 formerly irrigated acres in Arizona alone. Seventy-five percent of irrigation is threatened in Nebraska. Good air, land, water, and energy are the nuts and bolts of carrying capacity. The Carrying Capacity Network states (1991) the United States is "currently losing topsoil 18 times faster than it is being replaced; or that groundwater,...much of which we stored during the Ice Age and is nonrenewable, is currently being pumped out of the ground 25 percent faster than it is being replenished."
Close to home, here in Connecticut and along the Long Island Sound Basin, the effects of too many humans demanding too many water resources is apparent. Long Island Sound is located in the middle of one of the most densely populated regions in the United States. More than 8 million people live in the Long Island Sound Watershed. Every one of Long Island Sound's many environmental problems, from sewage and toxic chemicals to overfishing and habitat destruction, stems from its location smack dab in the middle of the most densely populated regions in the world. The Sound is a cesspool, drainage ditch, trash can, playground and food source to the millions of people who live and play in the region. For years, signs of the Sound's decline have been visible: the disappearance of dolphins, collapse of the flounder population, closure of more than on-half of its 120,000 acres of clam and oyster beds. (For a more detailed analysis of the effects of overpopulation on Long Island Sound see YHNTI Volume VII, 1997: New Haven: Your Coastal Community)
Despite this historic debate and profound evidence of man's destruction of finite natural resources, recent surveys show that Americans are less concerned about population than they were 25 years ago, and they are not connecting environmental degradation to population growth. A recent Gallup Poll showed that 78% of Americans considered themselves environmentalists and 71 % favored strong environmental protection, even at the expense of economic growth. It seems likely that Americans are not connecting population growth to environmental problems. Too often educators may present environmental problems without examining overpopulation as an underlying cause. These two issues--overpopulation and environmental degradation--must be linked more in education and in the media.
Too often environmental issues are presented in a vacuum, without further examination of underlying causes--primarily, too many people. Educators are not the only ones to fail to present this correlation. It seems linking population to the environment is unpopular. The media also does not want to approach the moral or religious implications of managing population. News articles were downloaded from Lexis-Nexis, the world's largest database of full-text news stories (using the connector "endangered w/2 species") and searched only stories in which the search terms "endangered" and "population" appeared within two words of each other. Just over 10% of a Lexis-Nexis sample of environmental news stories link human population growth to the environmental problems it affects. Even more significantly, only one story in a sample of 150 presents the view that limiting population growth might be a solution to environmental problems.
In the last 200 years, the United States has lost 50 percent of its wetlands, 90 percent of its old-growth forests, and 99 percent of its tall grass prairie. Every day, an estimated nine square miles of U.S. rural land is lost to development. These are dire statistics which are seldom attributed to environmental pressures associated with overpopulation. This fact is not addressed in the media. It must be addressed by educators or our students may be deprived of parks and playgrounds, wildlife and wilderness, rivers and beaches, rose gardens and silence.
Activities
A. Your Community E.Q.R.
Objective: Students use a rating system to indicate the environmental quality of their community. The class will develop an Environmental Quality Rating (E.Q.R.)
Procedure: Divide students into groups of two or three. Each group will investigate one form of pollution: water, air, land, noise, littering (surface), manufacturing. Study local pollution through observation and research. Each team will list all the sources of pollution within their area of specialty. Students should research different types of pollution in their area and include the specific types of substances that cause the pollution. For example, air pollution may contain chemicals may contain lead, carbon monoxide, sulfur dioxide, and smoke. From that list students will compile an E.Q.R. score. The teams will then share and aggregate their data to get a community E.Q.R. score. This score will give students some idea of the pollution problems their community faces.
Start with 100 points. Using the following criteria, record scores for the aggregate community E.Q.R :
Subtract the following points to calculate E.Q.R. If your community has:
Air Pollution
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mild -2
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moderate -4
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severe -6
Noise Pollution
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mild -2
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moderate -4
-
severe -6
Water pollution
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mild -2
-
moderate -4
-
severe -6
*subtract one additional point for every occurrence of a beach closing due to water pollution
Surface pollution
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mild -2
-
moderate -4
-
severe -6
Manufacturing
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mild -2
-
moderate -4
-
severe -6
If their community has a score of 100 on their E.Q.R., their community has no pollution. A score between 90 and 99 indicates mild pollution. A score between 80 and 89 indicates a moderate problem,. A score between 70 and 79 indicates an extensive problem. A score below 70 indicates their local pollution problem is severe. What does the final E.Q.R. indicate about pollution in your community? Are these problems expected to improve or worsen? If the population in your community increases 10%, how ill it affect these conditions? If it increases 25% If it doubles?
B. A Pretty Picture
Objective: Students will identify resources they find valuable, design a collage which represents these resources and understand how important the loss of these resources are to them.
Procedure: Each student creates a collage of all natural resources they appreciate and/or use...animals, trees, water, sunsets, for example. Each student is creating a patch for a classroom quilt of individual collages. The teacher should attach the pieces with wide, clear tape (such as packing tape). Once completed, discuss all the different resources they enjoy. After the discussion, rip the collage to elicit student response at the loss of their work and these resources. How would they feel if overpopulation took away some of their favorite resource? Remind them that natural resources will disappear if population growth continues unabated.
C. Garbage Costs
Start a large classroom trashbin and create "dollars" for students to use when they deposit trash. Create a price list for disposing classroom garbage. See if students can minimize garbage, thereby saving dollars to be used toward prizes.
