Global warming

        Global warming is an average increase in the temperature of the atmosphere near the Earth’s surface and in the troposphere, which can contribute to changes in global climate patterns. Global warming can occur from a variety of causes, both natural and human induced.

CAUSES OF GLOBAL WARMING

·         One significant cause is that carbon dioxide is expelled from our automobiles, minivans as well as other vehicles, and if these vehicles give off poor mileage you can be sure that there will be more CO2 being emitted into the atmosphere, which only contributes further to global warming.

·         Another cause is methane, which is next in rank to carbon dioxide as a greenhouse gas. The worst part of methane is that it has the undesirable property of being twenty times more effective in trapping heat in our atmosphere, and another worrying aspect to this is that methane levels have risen by as much as, it is believed, one hundred forty-five times in the last century.

·         Another cause of global warming, nitrous oxide, also for many decades, we have seen massive deforestation that is the second most important cause after carbon emissions, in making the world warmer than it should be.

THERE ARE TWO MAJOR EFFECTS OF GLOBAL WARMING:

·         Increase of temperature on the earth by about 3° to 5° C (5.4° to 9° Fahrenheit) by the year 2100.

·         Rise of sea levels by at least 25 meters (82 feet) by the year 2100.

THE THREE GORGES DAM IN CHINA AND ITS IMPACTS ON THE ENVIRONMENT AND COMMUNITIES.

THE THREE GORGES DAM IN CHINA AND ITS IMPACTS ON THE ENVIRONMENT AND    COMMUNITIES.

                   In 2006, the Chinese government completed a decades-long construction on the world’s largest dam ever situated in Central China. The Three Gorges Dam is 1.4 miles Long and 604' tall, over 5 times as large as the Hoover Dam. The three Gorges Dam is fed by the Yangtze River and its 26 turbines provide 18,000 megawatts of power.

Environmental Effects of the Three Gorges Dam

The most immediate environmental effects of the Three Gorges Dam have been an increase in landslide activity. This results primarily from erosion caused by the drastic increases and decreases in reservoir water levels, which, when at their peak, create a body of water almost as long as Britain. Another major issue with the Dam is the ways in which it is affecting biodiversity in the area. Animal and plant life has been greatly threatened due to flooding in some habitats and water diversion in others. Fragmentation of habitat may lead to heavy losses of biological diversity. Fragmentation of habitat, moreover, is disturbing the reproduction patterns of many species. Fragmentation leads to species insularization by creating virtual islands, which confound processes of ecosystem stability and biological enrichment. A number of species will be adversely affected by the construction of the dam. There are 300 species of fish in the Yangtze River. The dam will create a barrier in the river that these species will not be able to cross. Fish will not be able to travel upstream to spawn, so the populations of the species will decrease. Decreases in freshwater flow have meant that more saltwater is creeping up the Yangtze, endangering fish populations already threatened by overfishing. This again signifies a loss of valuable resources. the Dam may have been tied to major earthquakes, including the one in May of 2008 which killed 87,000 people by placing tremendous pressure and fluctuation (by rapidly raising and dropping water volume) on the underlying geological plates, TGD arguably increases seismic activity this leads to increased earthquakes, however, is more difficult. Still, there are already detectable increases in seismic activity. Towns and forests located in areas that will be inundated will have to be demolished and removed in order to increase navigability on the river. The loss of forests and agricultural lands will lead to erosion and the buildup of sediment at the base of the river and reservoir. This could lead to increased flooding upstream. Sediments and silt contain valuable nutrients necessary to agricultural production. The blocking of sediments behind the dam means that these nutrients may not reach fertile farmland downstream of the dam. This could reduce the fertility of the land. Other consequences of the Three Gorges Dam are lower temperature and dissolved oxygen content in water down-gradient from the dam. Dissolved oxygen is necessary for healthy aerobic activity in aquatic ecosystems. Fish and plants depend on oxygen to survive. The presence of the dam will disrupt the natural processes of aeration (the movement of water) and diffusion, ways oxygen dissolves into water. Water will move more slowly downstream, thus making it more difficult for available oxygen to be present in the water. This could have a negative impact on the aquatic ecosystem downstream.

Social Effects of the Three Gorges Dam in China

The most important effect that the construction of the Three Gorges Dam has had on Chinese society has been the displacement of millions of people from the Yangtze River region. In order to establish the reservoir, hundreds (possible thousands) of towns and villages were evacuated and later submerged.

References

Lin Yang (12 October 2007). "China's Three Gorges Dam Under Fire". Time. http://www.time.com/time/world/article/0,8599,1671000,00.html. Retrieved 2012 -06-02 William C. Jones; Marsha Freeman. "Three Gorges Dam: The TVA on The Yangtze River". Schiller Institute. http://www.schillerinstitute.org/economy/phys_econ/phys_econ_3_gorges.html. Retrieved 2012-05-01.

My thoughts on Rachel Carson's Silent Spring book

      Rachel Carson is best known for her 1962 book, Silent Spring, which is credited with beginning the modern environmental movement in the United States. That book turned public attention on the problem of pesticide and other chemical pollution, and led to such landmark legislation as the U.S. Clean Water Act and the banning of DDT in many countries throughout the world. Whatever Carson's arguments were in Silent Spring, they succeeded.
      The book also focused on the uncontrolled and often indiscriminate use of pesticides, especially dichlorodiphenyltrichloroethane (commonly known as DDT), and the irreparable environmental damage caused by these chemicals. The public outcry Carson generated by the book motivated the United States Senate to form a committee to investigate pesticide use. Her eloquent testimony before the committee altered the views of many government officials and helped lead to the creation of the Environmental Protection Agency (EPA).
         Silent Spring constitutes an extended argument for strictly limiting the use of pesticides, herbicides, and other dangerous agricultural and industrial chemicals, and for their careful application and safe disposal when such use is necessary. This argument rests on both factual and evaluative premises. Factually, Silent Spring's case rests on numerous scientific and accounts of the abuse of these chemicals.In my thoughts Rachel Carson's book made a major impact on the environmental health of the United States .

The link to cholera fact sheet."www.mercer.edu/enp/mph720/fact_sheet_oluwayomi_fabayo.pdf"

Rachel Carson

Rachel Carson is such a significant figure in heightening public health awareness about environmeantal health .

Rachel Carson, "Silent Spring" 1962
        A marine biologist and writer, Rachel Carson is considered the founder of the contemporary environmental protection movement. Rachel Carson's Silent Spring was published in 1962. it generated a storm of controversy over the use of chemical pesticides.She drew attention to the adverse effects of pesticides, especially that of DDT on bird populations, Throughout her book are numerous case studies documenting the harmful effects that chemical pesticides have on the environment. Along with these facts, she explains how the pesticides have done more harm than good in eradicating the pests they were designed to destroy. In addition to her reports on pesticide use, Miss Carson points out that many of the long-term effects that these chemicals may have on the environment, as well as on humans, are still unknown.

      In her book "Silent Spring," a 1963 National Book Association Nonfiction Finalist. At a time when technological solutions were the norm, she pointed out that man-made poisons introduced into natural systems can harm not only nature, but also humans. Her book met with great success and heightened public awareness on DDT, and DDT was banned. Several environmental interest groups including the Natural Resources Defense Council, the Wilderness Society, and the Environmental Defense Fund were formed after the publication of Silent Spring. Additionally, many believe that the establishment of the Environmental Protection Agency in 1970, can largely be attributed to the "concerns and the consciousness" that Rachel Carson raised in her book .

      Silent Spring helped to expose the hazards of chemical pesticide use, and draw public attention to environmental issues that had never really been addressed before. Silent Spring brought environmental issues to the attention not just of industry and government; it brought them to the public, and put our democracy itself on the side of saving the Earth. The onslaught of environmental legislation that occurred after the publication of Silent Spring allowed environmentalism to find credibility in our society, and its practice to become a permanent force in public policy. These describes why Rachel Carson is considered to be such a significant figure in heightening public awareness about environmental health.

Introduction to Cholera.

     Cholera is a severe diarrhea illness caused by ingestion of food or water contaminated with the bacterium Vibrio cholerae. In some developing countries where Vibrio cholerae is present, the bacteria contaminates drinking water, uncooked seafood, and other foods. Every year, there are an estimated 3–5 million cholera cases, and 100 000–120 000 deaths due to cholera. The short incubation period of two hours to five days, enhances the potentially explosive pattern of outbreaks.

 

An Environmental Sensitivity index Map showing the region of oil spillage.

 

 

 

Shorelines on ESI maps are color-coded by sensitivity to oil. Symbols mark localized areas for biological and human-use resources.