Human population
growth was relatively slow for most of human history. Within the past 500
years, however, the advances made in the industrial, transportation, economic,
medical, and agricultural revolutions have helped foster an exponential,
"J-shaped" rise in human population (Southwick, Figure 15.1, p.
160). The statistics associated with this type of growth are particularly
striking: "Human beings took more than 3 million years to reach a population
of 1 billion people...The second billion came in only 130 years, the third
billion in 30 years, the fourth billion in 15 years, the fifth billion in
12 years..." (Southwick, p. 159). As human population has grown, there
has been simultaneous growth within the industrial sector. Both of these
increases have greatly contributed to environmental problems, such as natural
resource depletion, ecosystem destruction, and global climate change. Also
linked with the increasing human population are many social problems, such
as poverty and disease. These issues need to be addressed by policy makers
in the near future in order to ensure the survival and sustainability of
human life.
One of the major
effects of the huge population increase has been the depletion of natural
resources and the destruction of ecosystems. In the 1960's, theorist Paul
Ehrlich predicted that, given the skyrocketing figures of human population,
the amount of food produced would not grow at a fast enough rate for human
survival (Professor Carr Everbach, personal communication). He predicted
mass starvation and death by the year 2000 as the result of uncontrolled
population growth. Clearly, this did not occur. Ehrlich did not foresee
the advancements made in fertilizer and farming technologies that have enabled
humans to greatly increase food production to sufficient levels.
Though Ehrlich
was ultimately incorrect in his hypothesis of mass human starvation, he
was correct to view the necessary increase in food production as problematic.
As more and more land is needed for agricultural purposes, several natural
resources are being exhausted. Furthermore, ecosystems are being systematically
destroyed in order to support the growing population. The necessary minerals
that give soil its fertility are constantly under threat of depletion by
over-farming, though new fertilizer technology has lessened this problem
somewhat. Difficulties are also occurring as some farmers search for new
agricultural locations. This problem is most evident in the destruction
of tropical rainforests. The large-scale clear cutting of rainforest, practiced
in many parts of South America, has potentially eliminated a significant
number of species that depend on the forests for survival. Humans might
be able to reap benefits from these unknown species, such as treating certain
diseases. Unfortunately, these benefits will remain unrealized with the
elimination of large tracts of rainforest. The systematic destruction of
large areas of forest can also potentially have severe climatic effects.
Some scholars believe that the burning of large Australian forests by ancient
homo sapiens brought about world climate shifts many thousands of
years ago (NPR, 2002). It is very difficult to understand and predict the
entire range of possibilities brought about by an event such as rainforest
destruction. Humans would therefore be wise to proceed with caution when
choosing the methods for obtaining greater agricultural production.
With the increase
in population, there has also been a dramatic increase in industrial productivity.
In particular, the burning of fossil fuels, such as coal and oil, have had
significant negative effects on the environment. Fossil fuels, an excellent
source of high energy, support a significant portion of our industrial activities,
such as powering vehicles, factories, and power plants. Unfortunately, these
resources are finite. Once humans have exhausted the earth of all its sources
of oil and coal, we will need to find alternative sources of energy. This
fact by itself is not necessarily problematic. Proponents of the "tech
fix" believe that humans will always find a new solution to whatever
problem is encountered. Thus, new technologies have been developed that
aid our search for fossil fuels, allowing humans to uncover vast new sources
of oil. Other possible "tech fixes" include discovering and perfecting
new sources of energy such as nuclear power (fusion or fission), solar power,
wind power, or water power.
Though the "tech
fix" argument provides many possible solutions for the problem of resource
depletion, industrialization has had other significant negative effects
on the environment. The burning of fossil fuels has substantially increased
the amount of carbon dioxide in the atmosphere (Quay, 2002). These increases
in carbon dioxide have, in turn, brought about increases in global warming:
heat from the sun that enters the earth's atmosphere is prevented from leaving
by so-called "greenhouse gases," of which carbon dioxide is a
major example. The retained heat has brought about significant increases
in the temperature of the earth's global climate (Hansen, et. al, 2002).
The effects of global warming have the potential to be disastrous. Polar
ice caps could begin to melt, leading to an increase in the water level
of the oceans, and the subsequent flooding of coastal areas. The temperature
of the oceans could rise, leading to the destruction of the many forms of
marine wildlife that can only survive within a restricted temperature range.
The shifts in climate could also negatively impact trees and plant wildlife,
as these species are unable to swiftly travel the large distances necessary
to accommodate the climate change. Though these problems could be solved
by human intervention, such as transportation of marine and plant wildlife
to their appropriate climates, there is little evidence to suggest that
humans are prepared for or willing to undertake these activities. The loss
of trees to climate change would be especially problematic, as it would
exacerbate the problem of global warming. One major source of carbon dioxide
uptake from the atmosphere is the trees and plants that use it for photosynthesis.
Elimination of a significant number of plant species would result in rising
levels of carbon dioxide, and, subsequently, increased global warming.
The large increase
in population has also had several negative social effects that interact
with technology and the environment. The greater population has necessarily
brought about greater consumption of natural resources, as more people demand
food, shelter, and material goods. Such high consumption of goods is associated
with increased levels of pollution (Southwick, p. 160). For example, as
more people drive cars, demand for oil, as well as air pollution levels,
increase. There have also been increases in poverty. Southwick points out
some very sobering statistics on world conditions: "One out of five
people in the world, including one out of three children under the age of
five, is hungry or malnourished. One out of five people has inadequate housing...One
out of three people have poor health care and not enough fuel to cook food
or keep warm. One out of four adults cannot read or write. Over a billion
people are seriously ill with preventable infectious diseases, including
malaria, tuberculosis, schistosomiasis, trypanosomiasis, and filariasis"
(Southwick, p. 160). As technology has advanced to help cope with rising
population numbers, many jobs have been eliminated, particularly within
the domain of unskilled or manual laborers. For example, computer operated
machinery has often been the replacement for humans on assembly lines at
automobile factories. This technology is necessary in order to accomodate
the growing demand for automobiles world wide, yet it has simultaneously
brought about the unemployment of the people who used to manually assemble
the parts of a car. As a result of the increasing unemployment and poverty,
cities have suffered overcrowding and homelessness. Overcrowding has also
helped spread infectious diseases, as dense population conditions allow
these diseases to thrive. These are just a few of the many social and environmental
effects of human population increase and technological advance.
Despite the widespread
negative effects of human population increase and industrial growth such
as resource depletion, ecosystem destruction, global warming, and poverty
increase, humans have met with many successes in solving or lessening some
of these problems. "Green chemistry" practices have sought to
reduce chemical pollution and provide cleaner methods of industrial production
(Poliakoff, et. al, 2002). Governmental policy regarding the use of CFC's
has significantly reduced the size of the ozone hole (Kerr, 2002). Finally,
technological advances and education programs on birth control have begun
to dramatically slow the birth rates of industrialized countries, and stem
overall population growth (Wattenberg, 2003). Researchers must continue
to search for new, environmentally safe methods of sustaining the burgeoning
human population before these problems reach the threshold of catastrophe.
References
Hansen, J., Ruedy, R., Sato, M., & Lo, K. (2002). "Global Warming Continues." Science, 295, 275.
Kerr, R. A. (2002). "A Brighter Outlook for Good Ozone." Science, 297, 1623-5.
NPR Radio Broadcast, March 17, 2002. http://discover.npr.org/features/feature.jhtml?wfId=1140067
Poliakoff, M., Fitzpatrick, J. M., Farren, T. R., & Anastas, P. T. (2002). "Green Chemistry: Science and Politics of Change." Science, 297, 807-810.
Quay, P. (2002). "Ups and Downs of CO2 Uptake." Science, 298, 2344.
Southwick, C. H.
(1996). "Chapter 15: Human Populations." Global Ecology in
Human Perspective. Oxford University Press, 159-182.
Wattenberg, B. J. (March 8, 2003). "It Will Be a Smaller World After All." New York Times: Editorial/Op-Ed Section.
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