The world's human population has been growing in what has been described as a j-shaped curve. In the early 1900's, the world's population numbered nearly two billion; it has more than tripled since then (Southwick 159). There are three theories or models for population growth. The Malthusian theory predicts that human misery and eventual catastrophe will be the limiting factors for world population. Logistic theory predicts that there will be some sort of gradual resolution as humans adapt and are able to support a population between eight and ten billion. The domed model of growth predicts that between eight and ten billion will signal overpopulation, so a readjustment of to lower levels would be attained (Southwick 159). These three theories are important because each has different implications for the environment.
Most ecologists consider human population growth to be one of the most pressing problems contributing to environmental degradation. Human population growth works in conjunction with excessive consumption to threaten global environmental stability (Southwick 160). It can be argued that a larger world population leads to an increase in human capital, thus making it possible to increase the world's standard of living. However, twenty percent of the world's population, including one third of the world's children are hungry or malnourished; twenty percent have inadequate housing or are homeless; one third have poor health care and insufficient fuel to cook or keep warm; twenty-five percent of adults are illiterate; the depressing statistics continue (Southwick 160). Dr. Julian Simon believes that the world is making progress because people are living longer and more fulfilling lives compared to their forebears, but he ignores the fact that there are also more people living in misery and destitution as well (Southwick 161). The statistics do not support Simon's argument, and they make a strong case for the need to be aware of population growth as an environmental problem.
Most scientists feel that a world population of between one and two billion can live on the Earth in a sustainable manner and with a reasonable standard of living (Southwick 161). As it stands, the world's population is at least three times that of the recommended level. Combined with what is a reasonable standard of living, that is to say that everyone would have an acceptable job, sufficient housing, a varied diet without fear of food and water shortages, adequate health care, education - all of the typical middle-class family values. Obviously, most people do not enjoy this standard of living (Southwick 161). If the six billion people presently populating the earth cannot attain such a standard of living, the population swells between eight and ten billion, how can they attain a middle class standard of living will the scare resources available? A flaw in Southwick's argument that Simon would probably argue is that with more people, comes more human capital. With more human capital, the likelihood that our innovation will discover a technological solution to the overpopulation problem increases. Other scientists compare population growth to the growth of a cancerous tumor. Both are characterized by rapid, uncontrolled growth, invasion and thus destruction of adjacent areas, spread to other, outlying areas, and loss of differentiation between individual components. Any two or more of these symptoms are indicative of cancer in the body; the human population currently displays all five symptoms (Southwick 161). Uncontrolled human population growth will not necessarily kill the earth, but civilization in its present form could collapse, as in the case of Easter Island.
Population growth occurs because there are currently three births for every death. In the past, the crude birth rates were only slightly higher than crude death rates, but with improvements in medicine and economic growth, the death rate fell more than birth rates (Southwick 162). Much of the world's population growth is occurring in less-developed countries, which are unable to support such growth. The causal effect between poverty and population growth can be looked at in two ways. First, population growth causes poverty as the limited resources are depleted and there are too many people for the available goods, resulting in poverty. The other view is that poverty causes high population growth because lack of education, lack of health care, and lack of a reasonable standard of living cause high population growth. Also, parents believe that having many children will ensure that several of them will survive to take care of them in their old age (Southwick 162). Cultures in which children are a form of security encourage high population growth, as children reach reproductive age and have large families.
Much of the growth is happening disproportionately in urban areas. Cities are environmentally harmful because they import many resources for the people that live there, and they export their wastes. They also have an impact on the local and regional meteorology and are centers for social problems such as crime, homelessness, and unemployment to name a few. Cities do offer many amenities such as cultural opportunities, jobs, and education. And there are some good environmental aspects to cities, such as the promotion of efficiency in transportation, housing, utilities; the provision of necessary goods and services; and the accommodation of large numbers of people within a relatively small space. The biggest problem with cities is that people want the benefits of a city while still living in the country (Southwick 169). This leads to urban sprawl and suburbia.
There are several strategies that could alleviate or even solve the population problem. One plan is educating adults and adolescents entering reproductive age about family planning (Southwick 170). However, many social and religious customs discourage contraception and encourage large families. Governments have dealt with the population problem in several ways. First they have simply ignored it (Southwick 178). This is akin to sticking one's head in the sand. Other governments have associated population growth with their national development problems; so have established state-sponsored family planning programs that have been helpful, but not really effective (Southwick 178-179). Third, some governments, such as Singapore's, have used economic incentives to limit family size, such as providing better housing for smaller families and tax breaks for families with two or fewer children (Southwick 179). Another option for governments is coercive action, which could be an assault on basic human rights. Fifth, a combination of education and economic incentive to encourage family planning could be used to bring about a decline in birth rates (Southwick 179). The sixth response is to devise a way to make birth control cheaper, more effective, easier to use, safer, and more widely available. Countries with declining birth rates use the last response, which is providing them with incentives to have more children (Southwick 180). All of these strategies are currently being utilized in countries around the world. Each strategy provides a differing level of effectiveness when dealing with the population problem.
Edwin Dolan proposes three solutions to the overpopulation problem. The first solution which he claims is loved by classical economists is the marginal subsistence solution. He claims that the poorest classes of society are be so disadvantaged, that their survival and reproductive rates will suffer. As the population continues to grow, the next lowest level is pushed down to the subsistence level, and eventually, the excess births of the upper classes are balanced by the excess deaths of the lowest classes (Dolan 59). The second solution is the absolute subsistence level, when eventually everyone reaches subsistence level, and is so exhausted from working that reproduction suffers (Dolan 60). The third solution is praying that a externality will lead to a fall of the birth rate, such as a fad of homosexuality sweeping the globe (Dolan 60-61). These solutions are interesting because they do not prescribe any governmental policies, but instead offer solutions that could naturally occur.
A clear understanding of the causes and possible solutions is
the first step to solving the world population crisis. If everyone understood
what stress overpopulation places on the environment, they would hopefully do
their part to protect our environment.
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