Introduction

It has been calculated that the human population is currently increasing by two percent each year (Brown, Harrison, and Hutchings 42). This is a much more rapid increase than has ever occurred in the history of the planet (see Figure 1). Especially high rates of population increase occur in India, China, and selected African countries (Brown, Harrison and Hutchings 51). It is clear that population growth must stop sometime within the foreseeable future due to various factors. Among these factors are limited food and water supplies, limited energy and natural resources, pollution, animal and plant extinction, and the contamination and scarcity of many other much needed materials. The two elements that regulate population growth are birth and death rates. The question then is whether a slow down in population growth will be a result of a decrease in births or an increase in deaths. If the population continues to grow without bound, nature will take over and the death rate will rise to solve the problem. Unfortunately, this is not the most attractive solution for us. Instead, we would rather control the number of births in order to attack the source of this world problem and save the Earth from being over-capacitated.
 

What Causes Growth?

At the beginning of the population increase, there were many factors that caused it to grow. With the industrial revolution came advances in agriculture and industry that gave way to individual families being able to afford more children. In addition, increases in our knowledge about nutrition and medicine helped us to have more healthy babies. When women take care of their bodies better, they are more fertile and therefore can have more children. With cures for fatal diseases including antibiotics and vaccines, these children are also able to live longer. Finally, there has been an increase in fertility due to a number of factors including a reduction in the average age at which menarche occurs and an increase in the number of menstrual cycles a woman has in her lifetime. Menarche refers to the age at which a girl has her first period and it has "been systematically falling over the past 100 years…[and] today is about 13 years or less, on average" (Cartledge 38). This means that a woman’s time of fertility is increasing to include most of her teen years. In addition, as recently as 200 years ago "women in the Western world averaged only 30 menstrual cycles in a life time. Today for women with two children it is nearer to 450" (Cartledge 38). These figures all give women many more opportunities to conceive children in their lifetime. These types of changes seem good for society, and they are in a sense that more people means more development for the world’s societies. Until the middle of the 20^th century, the population was not a major problem. People could move to other continents and later out of the cities to rural areas and space did not appear finite. In addition, these technological advancements allowed us to care for all of these people as well. In essence, the population took care of itself. It was around 1950 when the population began to skyrocket (see Figure 2).

When Population Becomes a Problem

As mentioned earlier, the rapid growth that is leading researchers and environmentalists to worry occurs in developing countries in Asia and Africa (see Figure 3). Because of the lifestyles in these countries, families are very large, and this is the root of the world’s population problem. In the United States and other industrialized countries, we may have the technology to support more children, however the fertility rates here are under control due to cultural norms and economic development. Thus, it is not a problem of technology, a lower death rate, or an increase in fertility that is giving us too many people today. The problem lies in the way women are treated in Third World countries and a couple’s motivations for having as many children as they do.

There are many reasons why living in poverty leads to a larger family size. First, there is less formal education available, especially to women. This means that women are unaware of methods of birth control, where to get them, and how to use them. In addition, the status of women in general leads to a desire to have more children. Most women in third world countries are working on subsistence farms; doing most of the work to support their families. Also, their low social status means that their work is not acknowledged as such. Women are the "breadwinners" in these societies, but they are not given credit for the work they do, nor are they consulted when problems of diminishing resources occur. These women have learned how to manage forest resources, conserve the soil, and use other resources efficiently; however, their status is so low that only men are able to control how resources are used. The women then feel that having children will give them economic security and a higher social status. Unfortunately, men also see children as a way of achieving social status. When living in poverty, there is no money to buy a big house or luxury car. Instead, couples use many children as a symbol of status. Also, it is thought that the more children one has, the better care one will receive in old age, making large families a form of economic security. These children not only continue the growth of the country’s population problem, but also continue a vicious cycle. Because they are born to help their mothers with farming, many girls are not exposed to any type of formal education. Therefore, these girls are never educated about the effects of their family size on the planet’s resources. In addition, population growth diminishes resources and increases the need for technology, both of which lead to more poverty. Resources are needed for survival, but the use of new technology to increase the supply of resources leads to a decrease in jobs. Because the population growth is highest in impoverished countries, an increase in poverty is detrimental.

Population and the Environment

"Population growth has had, and at present continues to have, a severe impact on our environment" (Zuckerman vii). In fact, it has been said that this growth rate is the primary environmental challenge we face, even though it is much ignored (Zuckerman 1, 81).

Diminishing Food Supply

With a constantly increasing population, the first and most significant crisis that the world will face is a shortage of food (Brown, Lester, R. and Kane 21). There are many measures of food security from the personal to the global. The two most useful global indicators are grain production per person and carryover stocks of grain (Brown, Lester, R. and Kane 22). Measuring grain production per person gives a sense of how much grain each person should consume. In other words, it can tell us whether overall food availability is improving or deteriorating. Carryover stocks of grain show if production is exceeding consumption or vice versa. If production does not exceed consumption worldwide, the human population will be on the verge of a hunger crisis. This is worsened by the fact that resources are not equally distributed (see Figure 4).
 

Not only are those in industrialized countries consuming too much, but also the people who do not get enough food are living in areas of poverty with larger populations (Zuckerman 30). Grain is the most useful measure of food security for two reasons. First, grain supplies half of human food energy intake, and it provides part of the remainder indirectly by being feed for livestock (Brown, Lester, R. and Kane 42). Secondly, grain is less perishable than fruits and vegetables and can be stored for later use. During the thirty years for which data are available, world grain stocks have ranged from a low of 159 million tons to 465 million tons (Brown, Lester, R. and Kane 46). As world consumption has doubled, the amount needed to provide an equivalent amount of security has also doubled. Unfortunately the day will come when it is impossible to keep the amount of grain stocks on track with consumption demand due to a lack of land suitable for agriculture and storage space. An agricultural revolution has already begun with the introduction of new high-yielding, fertilizer-responsive varieties of wheat, rice, and other cereals. If it is to continue, though, huge changes and large expenditures for development of irrigation, transportation, storage, food processing, and fertilizers will have to be made. In addition, we need to be careful about becoming too dependent on chemicals whose consequences on humans and the rest of the ecosystem are unknown.

Other Food Sources

Besides relying on grain and agricultural products for sustenance, it is reasonable to say that it might be possible for humans to rely on another food system, like the oceans. Unfortunately, we already know that today’s oceans are our least dependable source of food. There are forms of nutrition such as seaweed and plankton that are options for food; however, the popularity of these choices has not been high worldwide. In addition, the most common food source that we do get from the world’s waterways, fish, is becoming less and less of an option as population growth increases. The state of the world’s fisheries have made newspaper headlines that read "Too Few Fish in the Sea" and "Ban on Industrial Fishing Called For" (Brown, Lester, R. and Kane 75). According to marine scientists, all seventeen of the world’s major fishing regions are currently harvested at or beyond capacity (Brown, Lester, R. and Kane 76). So, then, it might be reasonable to ask why don’t we take better advantage of the world’s rangeland. Mainly this is because the land is either too dry or too steeply sloping to be cultivated. This land can be used to graze cattle and sheep; however, with the high demand of meat products in the market, our rangelands are also being grazed at capacity and beyond.

Soil Erosion and Land Degradation

The problems dealing with our various food sources also lead to environmental degradation of soil and water causing a handful of other problems. Land degradation is taking a heavy toll on dry lands that already compose 41 percent of the Earth’s land (Ricklefs et al. 9). Land degradation, if unstopped, eventually creates wasteland destroying the soil as well as the vegetation. From damage to agricultural dry lands as well as erosion, the world’s farmers are losing billions of tons of usable topsoil from their cropland each year. As a result, productivity is decreasing as expenditures toward ways of fixing the damaged land are increasing. Deforestation is also causing much soil erosion around the globe. This erosion then is actually a result of population growth and an increase in the livestock that grazes and the forests that are cleared – we need more wood and more meat (see Figure 5). Erosion occurs as a result of wind and water especially where demand for food is high and crop rotations are exploiting the land. Also, without trees, mineral nutrients are no longer recycled from deep soil layers. This causes soil fertility to go down. Based on the amount of soil that can still be cultivated without a loss of natural ecosystems, we have about 10 million square kilometers left, which is enough to feed the human population for 25 years (Zuckerman 32). After that, we need to find a way to grow more food in the same amount of space.

Water

Soil erosion also leads to more problems including flooding, over-nourishment of streams and damage to coral reefs. When trees that hold the soil in place are removed, the soil becomes eroded and it will actually clog waterways. The reservoirs and canals that supply and store water for irrigation are suffering from sedimentation as a result of this eroding soil. Silt carried by river water collects in reservoirs behind dams and fills storage basins. As a result, the capacity of water that the storage basin is able to hold declines and at times the basins are even destroyed (Ricklefs et al. 53). Water is not only needed for human survival, but also that of other living things on Earth, and continuing to have a clean supply is critical. As the population increases, not only does the demand for water increase, but the supply of fresh water decreases (see Figure 6). We do have an abundance of salt water; however, we do not have an inexpensive way to desalinate it. Pollution of water is mostly due to erosion and acid rain that can fall back down in any nation on Earth and can be so concentrated that it kills plants, fish and sometimes even forests. Dams have also been noted as an option for storing supplies of fresh water, however these can become contaminated as well, and they disrupt the natural flow of the waterway.

Extinction

As we have seen, most of our basic needs are being exhausted at a very fast rate and those that are left are becoming unusable. Not only is this food, soil, and water needed for our survival, but also for other plants and animals. In an effort to save ourselves from overpopulation, we sometimes don’t realize that we are causing other living populations to become extinct as well. The most affected places from human activity are known as "hot spots." These ecosystems are filled with endemic species that are in great danger of becoming extinct. Some of the hot spots include the coast of Chili, southwestern Australia, Cape Floristic Province in South Africa, and Tanzania (see Figure 7). If we are not careful with what we do to the other species that we share this planet with, we will be affecting the food chain more than we realize as well as destroying many potential nutritional and medicinal resources. Instead we need to provide a habitat suitable for "housing the Earth’s living library of genetic information" (Zuckerman 29). If not, we will face immense changes in the ecosystems of which we are a part. According to UCLA professor and biologist Jared Diamond, the next century will cause the extinction of "roughly one-half of the 30 million species that are estimated to exist [on Earth]… courtesy entirely of human beings" (Zuckerman ix).

Energy Sources

The use of various energy sources is the final problem stemming from human population growth. Population growth causes more consumption and exploitation of energy, chemicals, and nonrenewable resources such as coal, petroleum, and natural gas. If we continue to increase our consumption of the latter of these three resources by the same rate and the population continues to grow at the same rate, then we will run out of them entirely in 57, 24, and 31 years respectively (Zuckerman 31). These resources are obviously not going to be available forever, and other potential energy sources such as fusion and fission are not developed yet. With the technology we have these days, it is difficult to imagine life without cars and machinery. Unfortunately, these, along with factories, need energy and are the greatest polluters of our environment. As the population increases, the demand and usage of automobiles and other machines also goes up. This leads to unavoidable problems like the greenhouse effect and depletion of the ozone layer. In fact, when these effects occur, it also leads to drying of the soil, declining farm yields, and the attempt to find new sources of water, which then leads to a bigger increase in the need for energy and technology. All of these problems will increase as population continues to increase and more energy, food, and water sources are needed.

An Interdependent World

This type of interconnectedness is seen not only as a result of energy consumption, but also in every other effect that stems from population growth. The cycle discussed above is known as a general circulation model and it shows how a climate change based on greenhouse gases in the atmosphere is likely to lead to a drying of the soils during the summer. These processes in general are referred to as feedback processes wherein the consumption or contamination of one resource can lead to both direct and indirect effects, forming a cycle. The use of fossil fuels, for example, leads directly to global warming and indirectly to the use of more fossil fuels to cool homes that now experience hotter temperatures (see Figure 8). This type of cycle is not uncommon when dealing with such an interconnected system, and the fact that so many exist means for us that population growth as the source of many of these problems needs to be addressed directly before we destroy our planet.

What Can Be Done?

In order to fix our population problem there are a number of potential solutions, both short and long-term. Some are fairly common in literature on the population problem and others are more controversial. One thing that is agreed upon is that the projected growth in the world’s population will occur in developing regions (see Figure 9). For this reason, we will begin with the solution that goes right to the cause of the problem: families in Third World countries.

Women’s Rights and Economic Development

If women in developing countries are given control over their resources and given credit for the work they do, they will not need the security that having so many children brings. Instead they will have a credible social status and control over their education, employment, and family size. When women have an equal share in earnings, independence, and freedom, they can live peacefully with men and will have fewer children by choice without being limited directly in their reproduction rates. Finally, the children they do have will hopefully be formally educated so that they too will have choices in their life and will not be restricted by their social status. This type of change will not only require a change in the status of women, but also in the economic development of these countries. If the economy is given the opportunity to develop, couples will earn money and be able to bring their families out of poverty. This will then give them the ability to develop social status through the goods they possess rather than the number of children they have. This is what Mary Douglas refers to as "oysters and champagne." Acquiring status is a major goal of all humans as seen in all social mammals (Cartledge 40). Whether this status is gained by having a BMW or by having six or seven children depends on the type of society one lives in and the resources that are available. By giving developing countries the opportunity to industrialize and improve their economies, we are not only increasing jobs and decreasing poverty, but also decreasing the fertility rate. People will have a choice in using some of their resources to acquire goods, leaving a smaller amount for the raising of children. In this way, people may "willingly give up having some babies so that they can afford washing machines and motor cars" (Cartledge 42).

Education

A major way that economic development can begin is in the formal education of both men and women in impoverished nations. Education in schools will give way to knowledge that can help people improve their cities and villages economically which will lead to a life where children are not needed for status and financial support. In addition, the education of girls about what large families are doing to the world population and how it can be controlled with contraception will decrease the fertility rate. When women are educated, there is an additional benefit in that they too will want to hold jobs. When women have jobs, this also leads to less children. In countries where no women are enrolled in secondary education, the average woman has seven children, but where 40 per cent of all women have had a secondary education the average drops to three children (Cartledge 3). Once again, status can be gained through a means other than the number of children one has, this time by holding a job.

Birth Control

When couples are given the opportunity to see how their large families are affecting resources and the environment around the world, we can begin to solve our problem by increasing the availability of birth control. This is a much more immediate solution, however it will only work if the couples want to use it. This means that the motivation for having large families must be diminished. If methods of contraception as well as education in terms of family planning are given to men and women in impoverished countries, then the number of children in each family should decrease. In addition, both education about the population problem and an increase in women in the work force will cause women to wait longer to have children. This can also be helpful because "like smaller families, such delays in first births exert a powerful brake on population momentum by lengthening the time span between generations" ("Today’s").

Government Control

There are many researchers who have other ideas dealing with how the world and the United States specifically should slow population growth. First, there are some who believe that the above suggestions are not harsh enough. For example, there have been suggestions that we limit the number of children to two per woman in the United States reducing the total fertility rate (TFR) to 1.5 and decreasing the population problem. There are also ways in which we could discourage having more than two children, such as structuring health insurance, welfare, public housing space, schooling, and tax deductions so that benefits are more attractive for the first two children in a family. Of course this solution is not only possible in this country, but also world wide. Another idea for the U.S. is to slow the immigration rate. Even though at this time, high levels of population growth are found in poorer parts of the world, it will not always be the case. The more the world population grows, the more poverty there will be in all countries until sooner or later the death rate starts to increase and naturally stops population growth. Some population researchers who worry about an increase in poverty in the United States believe that we should begin to slow immigration to this country and help other parts of the world through foreign aid. One author in particular, Lindsey Grant, believes that we should "turn off the magnet" making the U.S. less popular as well as making it more difficult to stay here as an illegal immigrant. She goes on to say that a better system of identification would help in controlling our borders and, at least for now, keeping our own country’s population under control (Grant 210-1).

Foreign Aid

As long as the United States and other industrialized countries are controlling their own populations, it may be up to us to help those without the knowledge and resources to do so. Foreign aid in terms of funding education and providing birth control in impoverished countries will help decrease the birth rate and eventually, when people are more educated, will decrease the poverty level as well. In fact, the U.S. government has been providing citizens in other countries with family planning services for 30 years and the results have been incredible. While the number of citizens in developing countries using contraception "has multiplied tenfold," the average fertility rate "has declined from nearly six to fewer than four" ("Today’s"). In addition, "the U.S. contribution to this success story has cost less than four cents out of every $100 raised in taxes" ("Today’s"). In this way, even though the United States will have to spend money on this issue, they will be doing so for the good of the world. Help from other industrialized nations would also be helpful as the U.S. would not feel the entire burden. Thus, the sacrifice will not be too great and we will still be sharing the wealth.

Population Distribution

Foreign aid is not the only way that industrialized countries such as the United States are specifically affected by uncontrolled population growth. Although we mainly look at the rough birth and fertility rate statistics when determining where the population problem is centered, it is also useful to look at population distribution. This type of information tells us the relative numbers of people for each sex and age group. For example, in most industrialized countries, there are a lot of people who are middle-aged and very few younger and older people. In developing countries, on the other hand, the distribution takes on a pyramidal shape with younger generations forming the larger base of the pyramid (Mackenzie 223). This large number of young people means that in the near future more people will be having babies, increasing the excessively high birth rates. Alternatively, for the U.S., this means that our future will hold a larger population of older people not middle-aged parents. Distribution is not always considered when analyzing the world’s population growth, however, it could mean extra expenses for industrialized countries in terms of medical care. This also means a potential controversy over how much should be done to keep people alive and reduce our death rates. Although it does not cause the population problem in itself, distribution of populations can affect what solutions can be best applied.

Controversy in Solving the Population Problem

It is obvious that solutions are necessary to slow the rapid rate of population growth all over the world, but there are opposing viewpoints that lead to different theories about methods of controlling population growth. In developing countries, as well as those in which people are not poverty stricken, religion can play an active role. One of the most popular solutions currently for decreasing the birth rate is to increase use of birth control. Some people including Catholics who are against the use of birth control have actually taken a pro-population stance. These people and their beliefs are the cause of controversy behind many of our most promising solutions. They sometimes argue that the extreme population growth today is simply a natural part of the development of the world. In addition, it is thought by some that more people will lead to more technological advancements that will "alleviate poverty and other economic and social ills" (Zuckerman 89). Also, it has been noted that by giving too much support to family planning, we are leaning towards government restrictions of fertility, a severe solution. Most importantly, many of these people feel that abortion and birth control are unacceptable and that if population needs to be controlled, it needs to be done in a different manner. The question is what other way is there to efficiently control population growth that will not interfere with conflicting views in society?

What is the Best Solution?

Although there are many opposing views on how much action needs to be taken in relation to our increasing population, it is fairly common to believe that something does need to happen. This requires leadership in governmental offices and environmental groups who are willing to find potential solutions and determine what is best for the future of our planet.

We leave readers with the following analogy of "lifeboat ethics" created by Garret Hardin:

Discussion

Science and technology have undoubtedly helped us reach this level of rapid population growth that the Earth is experiencing. Many people are now expecting technology to solve this problem; however, we believe that it is highly unlikely that this will happen. Perhaps the theorized notion that the Earth will find a way to save itself is the only way that the human population will stop growing. Whether this is through an exhausted food supply or by humans populating an uninhabitable planet, we don’t know. It is difficult to say how long it will take for our population to decrease even if the most effective solutions are used. That is why it is so essential that we try to solve our population problem now in gradual steps rather than letting the Earth do it for us, which would most likely occur in a quick and devastating manner.

In order to solve this problem, many of the options such as birth control, education, and economic development seem fairly reasonable. By going to the root of the problem and trying to decrease the birth rate especially in impoverished nations, we will not only be decreasing the number of children that are born, but also allowing those who are born to live a healthier life, as resources will not have to be distributed among such a large family. In order to do this, the status of women needs to be improved and education especially in regards to birth control methods needs to be universal. This can be done through foreign aid and later, economic development of these countries until they are more independent. Because these solutions are not immediate, we must also learn to maximize our resources while the population is still at a critical level. This will include technological advancements and activities such as recycling and less overall consumption, which we can all do to help the planet. When these steps are taken, we can move toward a more secure world not only for the present time, but more importantly, for future generations.

Conclusion

Population growth is currently one of the biggest problems faced on this planet. Not only does it cause overcrowding in general, but a number of other problems. Many of the resources we take for granted are being diminished and even contaminated. For instance, we are running out of land on which to grow our food, and the land itself is becoming less and less productive. In addition, the erosion that causes this as well as pollution causes the supply of clean, fresh water to decrease. Energy resources are also being used up quickly and there are few alternatives. Finally, as we push more and more life onto this planet, we are leaving less room for other plant and animal species that are useful for nutritional and medicinal purposes as well as simply being a part of a diverse community. The most critical part of all of this damage is that most of it is interconnected. Damage to soil leads to less food and polluted waters. Over-consumption of energy leads to dryer soils and global warming. Without finding a solution to the cause of all of this, a rapid population increase, we will not be able to save the Earth from a continuation of this type of devastation. There are many different views on what solutions are best for action today. However, it is agreed upon for the most part among researchers and environmental groups that some action does need to take place. Because it is not reasonable to increase the death rate in order to control population, it leaves us with only one choice: decrease the world’s birth rate. The amount of action we take will determine exactly how much we decrease the fertility rate and therefore where our population is headed (see Figure 10). Whether this is done through education about birth control methods or the use of technology to determine new ways to use the resources we have left, we need to start today so that there will continue to be a habitable planet tomorrow. "When confronted with the frequently made argument that people are a good thing, so let’s have more of them, we can reply, following Herman Daly: ‘Yes, let’s have as many people on this planet as possible – but not all at the same time. Let’s populate the world with people for as long into the future as possible, by taking care that we limit population growth now’" (Zuckerman 45).