Environmental Science Worksheet Essay

1. What would you include in a brief summary on the history of the environmental movement? The environmental movement is closely related with the appearance of environmental awareness. Before 1960, very few people knew the term ecology. Environmental concerns were absent in the political and social spheres. However, a groundbreaking book by Rachel Carson, Silent Spring, was published in 1960 and large numbers of people became aware of the consequences of humans’ encroachment upon the nature in terms of the use of highly toxic chemicals like the DDT. Again in this period, various environmental events like oil spills, news about the possible extinction of several species have also helped create an awareness of the issue (Botkin & Keller, 2011, Ch. 1). People were divided into two camps: environmentalists (those having dismal views that life on earth is in peril) and anti- environmentalists (those opposing the environmentalists and saying science and progress are necessary for humans). Today we have overcome this either-or dichotomy and understood that science and progress do not need to be poised against the environment. Environment can be protected while industrialization and progress are maintained. Clean energy, new environmental regulations, and energy-efficiency are belied to help humans protect the nature. 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? Exponential growth is occurs when a population increases by a fixed percentage every year. Exponential growth is encouraged in the nature when a species is introduced to a new environment or when the population of a species is small and environmental conditions are suitable for the species. However, exponential growth does not last long in the nature. Exponential growth is bad since continuously high reproduction rate for a species places extreme pressure on ecosystems. Logistic growth curve explains how exponential growth is stopped by limiting factors like natural resources. A population might grow sharply at the beginning but as the limiting factors (like water, space, food, predators, and disease) come into play, the growth levels off (Withgott & Brennan, 2009, p. 85). As for human population, exponential growth is promoted by new medicines that staved off many diseases, dependable supply of food all around the year through scientific agriculture involving artificial fertilizers, and the eradication of predators. As for the limiting factors, lack of urban space, collapse of habitats supporting human life, war, occasional epidemics (like AIDS or flu), and declining fertility of overused agricultural areas are all serious obstacles to higher population growth. 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? Why should population growth be predicted?†? What will happen if there is exponential human growth? Human population and its dynamics have very important implications for the nature. Exponential human growth would have disastrous effects on the nature because a larger population means greater need for space (and hence, enlargement of cities into virgin territories), for food (turning more virgin territory into agricultural lands), for water (diverting more water resources into cities for human use and endangering animals and plants). So, population growth should be predicted to better reconcile the future needs with the necessity of protecting nature. Population predictions allow decision makers to make adjustments. Healthcare system, education, national security, and economics are the main areas that population predictions affect. Population growth predictions for developed and developing countries differ widely. This is due to the so-called demographic transition. In an underdeveloped country, birth and death rates are high and the actual population growth is low. However, industrialization leads to improvement in health and death rates decrease as a result while birth rate is still high. Then, at the next stage, a high growth rate is maintained. But education and material welfare increase and family-planning methods are widely adopted. Consequently, birth rate decreases and nears the death rate. A zero growth rate occurs. Developed nations like the US, Germany, and Japan are at the furthest stage of population growth while developing nations experience declining death rates and still increasing birth rates. It is difficult to predict the growth of Earth’s human population because there is always the possibility of a natural disaster, and it is not certain whether some developing nations can arrive at zero-growth stage before facing catastrophic circumstances (Botkin & Keller, 2011, Ch. 4). 4. How do principles of system theory apply to the Earth as a living system? Explain interactions between humans and natural ecosystems. The system theory and especially the Gaia Hypothesis see the Earth as a living system. According to this hypothesis, life changes the environment for the continuation of life. Hence the conclusion is the Earth can achieve physiological self†regulation. The principles of the system theory can be summed as follows: systems respond to inputs and outputs through the feedback mechanism. Positive feedback hurts the balance while negative feedback promotes stability. Relations between inputs and outputs of systems can be various: linear, exponential, or defined by a logistic curve. The so-called principle of environmental unity basically holds that every component of the environment affects another component. According to the principle of uniformitarian’s, we can forecast environmental conditions in the future by looking at the past and present trends. Change in the nature can be slow, rapid, sudden or expected. Interactions between humans and natural ecosystems occur can be explained through all these principles (Botkin & Keller, 2011, Ch. 3).