Provide a brief summary of the history of the environmental movement.
The environmental movement began when people saw either a problem with their waters, forests, and other natural resources. Even as early as the middle ages, farmers in the East and what would become South America realized the need for crop rotation to prevent soil erosion. In Europe, the plague prompted improvements in the public health system, particularly to improve the water. Also, due to Englanders nearly depleting all of their forests, they switched to coal—a resource that would later cause many more health problems, especially in the larger cities. Beyond that, as health problems arose over the centuries, people saw a need to improve their environment. The environmental movement became more organized in the 1960s when the Cuyahoga River in Cleveland, Ohio, caught fire and in 1969 when UNESCO’s Man and His Environment conference prompted the international community to work together on environmental issues. In the early 80s, the Environmental Protection Agency was founded and spearheaded massive cleanup efforts to improve the environment. In the 80s, the Chernobyl disaster, along with several other worldwide incidents, sparked further reform. In 1987, world leaders signed the Montreal Pact, promising to support the environmental cause. The same year, reports on ozone layer depletion served to bring about the ban of aerosols by the 90s. When George W. Bush was elected president in 2001, however, environmental regulations became more relaxed in spite of the mounting evidence for global climate change.
2. Explain the main point concerning exponential growth and whether it is good or bad. Compare exponential growth to a logistic growth curve and explain how these might apply to human population growth. What promotes exponential growth? What constrains population growth?
The population growth is dependent and thus proportional to the birth rate, which is the main variable. Exponential growth contends that the population will increase (exponentially) given that the population does not lack resources such as food or water and if it is never limited by diseases. The logistic growth curve, which is an S shape, is determined by numerous variables or constraints, including death, environmental factors, and disease. However, just because the population growth slows, the birth rate may not. Exponential growth will ultimately occur when the birth rate is high, health conditions are good, and resources are plentiful.
3. Compare predictions for human population growth in developed countries versus developing countries. Why is it difficult to predict the growth of Earth’s human population?
Most population growth is occurring in developing countries where there is still a lack of birth control. Even still, many developing countries are experiencing medical advances, which do result in fewer deaths. In developed countries, where they are more educated and have access to birth control, the population growth is steady.
It is difficult to predict the growth of the Earth’s population growth because of the possibility of diseases, famines and wars. In the past, the population growth was predicted to be 9 billion by the year 2050; however, due to several factors—including the AIDS epidemic in Africa—researchers are now predicting that it will be around 8.9 billion.
4. Explain how principles of system theory apply to the Earth as a living system.
The systems theory holds that different parts of a system have a structural and functional relationship with each other. The relationship between systems can have a cause and effect on the other. When a nonlinear interactions occur between the systems occur, the results are chaotic. While humans (which can be considered a system) interact with and attempt to control the Earth, which is itself a living system, the effects could be devastating. What must ultimately occur is a balance between the systems so that one system does not harm the other. As a living system, the Earth will attempt to self-regulate on its own when other systems fail to achieve equilibrium with it.
Kovarik, W. (n.d.). Environmental history timeline. Radford University. Retrieved on July 6, 2011, from: http://www.radford.edu/~wkovarik/envhist/about.html.
Population growth over human history. (2006). Global Change. Retrieved on July 6, 2011, from http://www.globalchange.umich.edu/globalchange2/current/lectures/human_pop/human_pop.html.
Pidwirny, M. (2006). Definitions of Systems and Models. Fundamentals of Physical Geography, 2nd Edition. Retrieved on July 6, 2011, from: http://www.physicalgeography.net/fundamentals/4b.html
Walonick, D. (1993). General systems theory. Retrieved on July 6, 2011, from: http://statpac.org/walonick/systems-theory.htm.