The Human Carrying Capacity of Earth - Essay Example

? The Human Carrying Capa of Earth The human carrying capa of the earth is not only a mere concept in the study of populations but also one which carries a whole lot of implications and complications. Information and in-depth study on the human carrying capacity of earth will somehow answer the question ‘why human living standards seem to be getting worse despite the fact that there are numerous efforts of the government at improving human life and existence’. Nevertheless, one eventually discovers that carrying capacity depends on the interplay of three factors: the forces that drive its imbalance, the natural resource base that maintains it, and the efforts of the governments in stabilizing it. The Definition of Carrying Capacity The carrying capacity of the earth is “the size at which a theoretical population would stabilize,” or “the theoretical equilibrium population size at which a particular population in a particular environment will stabilize when its supply of resources remains constant” (Muir 1). For Patricia Muir, the carrying capacity of the earth is the maximum theoretical population size that will remain stable if and only if the supply of resources does not change. However, this is indeed theoretical at best because not only does population size change all the time, but the supply of resources also change independent of population changes. The worst case scenario, therefore, based on Muir’s definition, is that the population size will keep increasing, the supply of resources will keep decreasing, and this will most likely drive the population to instability. Stability, as implied by Muir, is the state where the population may not experience any social or economic problems related to survival and ease of living. Sarah Postel, in her article “Carrying Capacity: Earth’s Bottom Line,” defines carrying capacity in a rather simple way as “the largest number of any given species that a habitat can support indefinitely” (4). There is no idea of stabilization driven at here by Postel, as based on her definition, carrying capacity is simply the capacity of the earth to feed a certain maximum number of people, whether or not this will lead to stability. Nevertheless, the definitions of Muir and Postel are far from the reality of the situation for several other factors that affect carrying capacity are not being considered in their definitions. Based on data from Cornell University, the carrying capacity of the earth is estimated to be 10 to 15 billion people, but estimates since 1679 by Anton van Leeuwhenhoek to the present have varied at the range between 1 billion to over a trillion people. The variations are due to the fact that it is admittedly “difficult to estimate” the human carrying capacity of the earth (The Carrying Capacity). The true reason behind this degree of uncertainty is that the world has been different in different eras in history and humans had different needs and different lifestyles for every part of his history. This is evident during the sudden exponential rise in human population from 1400 to the present while it remained fairly stable centuries before 1400, and no one knows for sure why this happened (Cohen 341). Another reason for the uncertainty in determining the carrying capacity of the earth is that the governments of the world do not exactly know what factors ultimately determine carrying capacity. Among the factors being considered there are food, nutrients, space, technology specifically and the availability of each (The Carrying Capacity). Still, other experts say that the problem is not within the environment but with people’s social, political and economic activities, which are all affected by culture, religion, language, values and ethnicity (Cohen 341). Others like Hardin theorize that the earth actually has its own natural way of correcting its own carrying capacity and the problem is that people’s ethical beliefs, like “Human life is sacred”, interfere with the earth’s own natural affairs; thus, the world ends up with more problems concerning its carrying capacity (Hardin 345). Nevertheless, there is a need to delve into the study of the human carrying capacity of the earth because of the clear and present danger that faces human beings now: “The population would double in 43 years if it continued to grow at its present rate of 1.6% a year” and “can earth support the projected population of 12.5 billion people by the year 2050 [and] if so, at what levels of living?” (Cohen 341-342). There is indeed a clear and present danger based on the information provided by Joel Cohen in his article, “Population Growth and Earth’s Human Carrying Capacity,” but just like Hardin, he finds out that every possible solution has a flaw in it and the best course of action would be perhaps to leave Mother Earth to take its course and take care of its own system of checks and balances. Nevertheless, one still has to know what specific natural forces drive the human carrying capacity of the earth towards imbalance. The Driving Forces One of the driving forces that cause an imbalance and other undesirable changes in the carrying capacity of the earth is the growing inequality of income between the rich and the poor. According to information by Sandra Postel, while the wealthy people’s share had increased from 70% in 1965 to 83% as of 1994, the poorest 20% of the world saw their shares in the income go down from 2.3% to 1.4% in the same year (5). Considering that this is data from 18 years ago, the situation is indeed much worse now. Nevertheless, the point is this worsening inequality in income is the main cause of environmental decline where it fosters poverty and lack at the bottom of the income ladder and an overwhelming degree of overconsumption of natural resources among the rich. While the rich use up energy and raw materials in their extravagant habits, the poor do the same by cutting down trees and grazing cattle from one day to another in order to survive (5). The gradual loss of resources will then eventually drive more and more people into famine, disrupting the carrying capacity of the earth. The next type of force that drives the carrying capacity of the earth towards imbalance is economic growth. Although the term “economic growth” seems a positive one, it fosters the overconsumption of natural resources like timber, minerals, fossil fuels and water, thus causing considerable damage to the environment and this has naturally led to an imbalance in the carrying capacity of the earth. The third and last driving force that is worth mentioning and that is much easier to comprehend with is population growth. The United Nations projection of 8.9 billion people by 2030, and the 12.5 billion projection by 2050 are both alarming and threatening to the human carrying capacity for very obvious reasons (Postel 5; Cohen 341). Thus, the three previously mentioned driving forces are the ones that humans have to deal unless we want the human race to be extinct or we want to see another world war. However, aside from knowledge of the forces that cause changes in the carrying capacity, one also needs to know the basic current resources of the earth, which are those that maintain the carrying capacity. Any disruption of these resources will also eventually result in imbalances in the capacity of the earth to sustain human beings. The Current Resource Base of Earth The first and perhaps the most important resource base is cropland, for it is where the grains and food are harvested for all humans of the world to eat and survive. However, with advancement in industries and technology, huge portions of croplands are being lost to road construction, housing and establishment of businesses – all in order to accommodate an increasingly growing population plus increasing demands (Postel 7). Unless the factors that cause destruction and conversion of croplands are stopped or mitigated, eventually there will be less and less grains and plant food produced. Perhaps, there will be either an increase in the prices of food or a decrease in its consumption because of high prices. Either way, the human carrying capacity of the earth is disrupted. A second resource base is pasture and rangeland, which once covered around 3.4 billion hectares of land, and which was twice as large as that devoted to crops (Postel 8). However, overgrazing and conversion have also overtaken this natural resource base, thus food economies will begin to weaken as soon as a decrease in cattle production is felt. This will also impact on the economy through an increase in the prices of meat, which will make people work harder and destroy more croplands and rangeland in the process. Furthermore, if protein becomes expensive, there will be a corresponding decrease in the nutrition of those who will not be able to afford it. Fisheries are another resource base that helps maintain the human carrying capacity of the earth. However, the problem with fisheries is the overconsumption of fish, not even counting fishing methods that would destroy small fishes, corals, and other breeding grounds of fish. Although there are better fishing management methods now, the destructive threat to the fisheries remain (Postel 9). Less fish would mean less food and a consequent imbalance in the carrying capacity of the earth. Fresh water is another natural resource base that is slowly dying out (Postel 9). In fact, a considerable decrease in the supply of water will slow down eventually food production as well as impede agricultural production because of slow irrigation. If food production is disrupted, the carrying capacity of the earth is once more negatively affected. The last but certainly not the least natural resource base is the forest and woodlands. Without woodlands, there would be no logs, lumber, fruits, nuts, and fuelwood for cooking and heating of food or of the temperature. The forests also maintain ecological cycles like water cycles, storage of carbon and the protection of air quality as well as sheltering millions of species of plants and animals. The problem is that with around 4.5 billion hectares of forests around 300 years ago, the number has been recently reduced by 24% to 3.4 billion (Postel 9). The extinction of exotic plant and animal species may not greatly affect carrying capacity, but the loss of lumber and fuelwood will certainly do as well as the destruction of the water cycle. The question now is whether something should be done about the gradual destruction of the resource base of the earth. If so, then what is it? If not, then why? This is where Hardin comes in. The Present Problem and the Moral Dilemma Garrett Hardin, in his article “From Shortage to Longage: Forty Years in the Population Vineyards,” theorizes that almost all efforts of the government at maintaining the carrying capacity of the earth are futile, and that at best we should just leave the task of maintaining the carrying capacity to Mother Nature. According to Hardin, efforts of the government to save lives by supplying starving people with food have one of the most destructive long-term consequences to carrying capacity. If, therefore, there is overpopulation and starvation, the natural consequence is that “an excess of population is soon corrected by excess mortality” (Hardin, “From Shortage to Longage,” 344). However, if food is supplied to the starving people in a particular country like India, the result is that they will ask for more food the following year and every other year since the environment is basically the same (Hardin, “Carrying Capacity,” 53). What is worse, the starving people who were fed last year will have already multiplied by the time they receive the next help. Indeed, the man does not live on bread alone but on a means to acquire it – perhaps, energy or a resource base in the starving country should be established. Yet things are always much easier said than done. For Hardin, perhaps, the starving people are better left alone. Another theory that Hardin wants to debunk is the population control program of governments as a means for decreasing populations to hopefully restore the earth’s carrying capacity. According to Hardin, “Population control is a community need [but] birth control is a personal activity,” which means that childbirth can never be actually stopped as long as humans are able to and intend to exercise their free will (Hardin, “From Shortage to Longage,” 346). Thus, population control cannot really do much; perhaps, not until a human being has experienced the dire consequences of overpopulation can he learn to control his desires for having more children. Hardin is implying that nature has its own checks and balances in order to maintain stability. A third theory that Hardin criticizes is the child-survival hypothesis which states that since the poor are poor, they tend to consider their children as a form of insurance. The converse statement is therefore obvious – make the poor extremely wealthy in order to reduce childbirth. However, Hardin asks, “Is this true?” (Hardin, “From Shortage to Longage,” 347). Perhaps, the factor here is attitude and not exactly economic status; probably, the proponents of the child-survival hypothesis have not thought that when poor people have become rich, they would think they have enough means to bring up children – only this time it is more rational. A fourth point raised and criticized by Hardin is the idea of granting social welfare to the poor together with laissez-faire birth control methods. However, even if people decided to have fewer children, with social welfare they would eventually think that the state will hold responsibility for their children, and so there will be more childbirths. On the other hand, if there is no social welfare, the couples will be able to at least learn how to take responsibility for the number of children they have and will have (Hardin, “From Shortage to Longage,” 348). A fifth point raised by Joel E. Cohen in his article entitled “Population Growth and Earth’s Human Carrying Capacity” is the idea of developing more technology, which is the idea of people that Cohen would call the “bigger pie” school (Cohen 344). The last point raised is to “improve the terms under which people interact,” which is the idea of the “better manners” school (345). Unfortunately, Cohen is pessimistic about these two points as people naturally have a tendency to neglect the consequences of their actions to the environment and to others. This is called “the tragedy of the commons,” and when they neglect the consequences of having too many children, it is called “the second tragedy of the commons” (345). Indeed, it would be next to impossible and downright futile to impose anything to change the attitude of human beings. Cohen, however, implies two solutions – considerable scientific data in order to rationally convince people of the consequences of their action and instilling in them the spirit of voluntary social action in order to act positively without thinking that they are being told to do so. Conclusion The human carrying capacity of the earth is and will most likely be affected by the existence and occurrence of growing inequality of income between the poor and the wealthy, the consequences of economic growth, and the reverberations of population growth. Moreover, the carrying capacity is also driven to imbalance when negative changes occur to the natural resource base – the croplands, pasture, fisheries, fresh water and woodlands. The question that comes up is what should be done to prevent the imbalance. However, although the governments of the world have answered it with charity, population control, social welfare, technology, financial assistance, and education, ecologist Garrett Hardin and population professor Joel Cohen believe that any human effort towards maintaining the human carrying capacity or increasing it will have negative consequences because of the human factor. Cohen, however, believes that more available and accessible scientific information and the development of voluntariness in each one could help solve this dilemma. Top of Form Bottom of Form Works Cited Cohen, Joel E. “Population Growth and Earth’s Human Carrying Capacity.” Science, 269.5222 (1995): 341-346. Print. Hardin, Garrett. “Carrying Capacity as an Ethical Concept.” University of Montana. The Social Contract, Fall (2001): 48-57. Web. 26 Oct. 2012. Hardin, Garrett. “From Shortage to Longage: Forty Years in the Population Vineyards.” Population and Environment: A Journal of Interdisciplinary Studies, 12.3 (1991): 339-349. Print. Muir, Patricia. “Carrying Capacity (K)” 2000. Oregon State University. Oct. 2011. Web. 30 Oct. 2012. Postel, Sandra. “Carrying Capacity: Earth’s Bottom Line.” Challenge, March-April (1994): 1-12. Print. “The Carrying Capacity (K) of Earth.” Cornell University, n.d. Web. 27 Oct. 2012. Read More