This essay will address the question, what is global warming, and how is it affecting the Earth and its inhabitants? Despite much media coverage of the role of human activity in the furthering of harmful global warming effects, the majority of the general public does not view global warming as a definite and imminent danger. Robert T. Watson supports this in his comment about society s failure to recognize the severity of a potential environmental disaster as a result of global warming. It is important that society treat human-induced global warming as a serious global-scale environmental threat. The overwhelming majority of scientific experts believe human-induced climate change is inevitable. The question is not whether climate will change in response to human activities, but rather where (regional pattern), when the rate of change) and by how much (magnitude). ----- This essay will examine how global warming is affecting world temperature, plant growth, the oceans, agriculture, animal life, and human life.
In recent years, the term global warming has been associated with such phrases as impending environmental disaster , the greenhouse effect and the most serious environmental threat of the 21st century (Newton, 1993). Global warming is defined as an increase in the average temperature on Earth. The increase was first detected in the 1980 s. The cause of global warming is believed to be the greenhouse effect. This is the process of trapping heat with the Earth s atmosphere due to the presence of large amounts of carbon dioxide, chlorofluorocarbons, methane, and nitrogen oxides.
The most prevalent issue of global warming is the increase in overall world temperature. In the thirty year time period of 1951-1980, a 0.47 degrees Celsius temperature increase has been documented (Hansen, 1998). Michael D. Lemonick predicts that unless the world takes immediate and extreme steps to reduce the emissions of heat-trapping gases, global temperatures could be driven up by as much as 6.5 degrees Fahrenheit by the year 2100.(Lemonick, 1997) This drastic temperature change is comparable only with the one that occurred at the end of the last Ice Age. The effects of this temperature rise, in collaboration with projected temperature increases, transcend over almost every aspect of society and ecology.
An alteration in the earth s plant growth will accompany the changing temperatures. The forest regions would be affected adversely. According to Jill Jaeger, the reproductive abilities of many tree species would be reduced by a warming trend that would threaten both tree and plant mortality. Major effects on forests are estimated to begin around the year 2010 with forest dieback starting between 2025 and 2050. A warmer, drier climate would also lead to increased forest fires and what research ecologist, Daniel Fagre, calls a nixing out of such rare alpine plants as the Glacier National Parks northern eye-bright and the whitlewort. While some species of tree, such as the lodge pole pine, would increase in population, the majority overall species could collapse. If, under projected global warming conditions, a 500-year-old cedar forest in the Lake McDonald valley were to be wiped out by a forest fire, the trees reproductive abilities would be so hindered by a hotter, drier climate that they would not be able to restore their species population in the area. (Jaeger, 1998)
Global warming will also incur a serious impact on the world s oceans. Confirmation is already apparent in numerous areas of the world. Glaciers are disappearing globally. In the past fifty years, four Antarctic ice shelves have collapsed. Ice slabs as large as Rhode Island are breaking off and floating into the open seas (Moore, 1997). In the Alps, the ice masses have lost half their size since the middle of the 19th century. El Nino, the Pacific Ocean phenomenon that causes a warm current along Peru s coast, has occurred every year since 1991. El Nino has caused crop failures in Australia and floods in California (Spiegel, 1997).
In the past century, the world s sea level has risen by nearly eight inches. The temperatures of the oceans themselves are also rising. For example, the temperatures of the upper layers of water in the tropics have warmed by 0.57 degrees Celsius in the past 50 years (Spiegel, 1997). Warming temperatures cause the ocean waters to expand, mountain glaciers, to liquefy, and possibly some portions of the polar ice caps to melt (Newton, 1993). Rising sea levels are a particular concern of scientists around the globe because they can lead to changing shorelines or even the entire submergence of some island nations (Newton, 1993). A personal anxiety of the United States is suggested by George J. Mitchell in the fact that five thousand to ten thousand square miles of United States dry land could go under the ocean sometime in the ensuing hundred years. Globally, the submergence of coastal lands is anticipated to displace a quarter of the world s population by the end of the next century. Mitchell also points out that rising temperatures, combined with the effects of rising seas, could possibly wipe out entire fragile oceanic coral reef systems. Since the first observations of coral demise in 1979, coral reef extinction has been recorded in sixty places (Moore, 1997). This example of the destruction of an ecosystem is just one of the harmful ways that life on Earth could be disrupted.
Seas level elevations would also induce increased erosion. James G. Titus, a senior scientist with the U.S. Environmental Protection Agency, concludes that even a 30-centimeter rise in sea level would result in beaches eroding 20 to 60 meters or more. On an economic note, Titus also suggests that sea level rise would increase the costs of flood protection and flood insurance in coastal areas (Newton, 1993). Kathlyn Gay poses another impact of sea-level rise. If sea levels were to elevate enough to reach freshwater sources, it would mean the intrusion of salt water into rivers, streams, and groundwater sources. This would affect the amount of drinking water available to land animals and the human population causing the transformations of entire ecosystems (Gay, 1995).
Global warming will also alter agriculture. As Kathlyn Gay proposes, changes in agriculture are likely to occur as effects of alteration in precipitation patterns, shifts in water supply, and variations in water distribution brought about by global warming. Furthermore, Gay believes that the United States will feel the greatest agricultural impacts from a greenhouse warming out of all industrial countries. Gay states, any significant drop in the yield of corn and wheat plus soybeans (the three most valuable U.S. agricultural products) could have a detrimental effect on the nation s economy as well as create food shortages on a global scale. Unlike developed countries, third world nations will be even more affected by variations in agriculture patterns because they do not have the scientific knowledge that is needed to create farming equipment adapted to a warmer climate. Those that are not now selfsufficient in terms of food reserves may lack the funds, technology, and even the desire to make farreaching changes in farming practices that could possibly save their inhabitants (Gay, 1995). David E. Pitt believes that the greenhouse effect, the major cause of global warming, will lead to famine in under-developed countries primarily because of their projected inability to adapt. Pitt cites a scientific study conducted by Dr. Rosenzweig of Columbia University and Prof. Martin L. Parry, director of the Environmental Change Unit at Oxford University, as basis for his theory. The study predicts that rising temperatures resulting from greenhouse gas emissions will cause only a slight to moderate decline in world grain production, causing prices to rise, but leaving most industrial nations more or less unharmed-and actually increasing crop production in some. But people in already impoverished countries are likely to face more starvation and malnutrition than ever before, despite the efforts of farmers to counter the effects of rising temperatures on their harvests. The staple crop of rice, for example, can be grown only in a narrow range of temperature and humidity. If the earth s temperature were to rise by even a few degrees, it would be enough to seriously reduce the amount of rice that could be harvested for human consumption. Therefore, even the slightest of temperature variations could seriously impact the agricultural world and the amount of food available to the human population.(Pitt, 1997)
Perhaps the group most unjustly affected by global warming is the animals. Though they seem to have no role in the causes of global warming, they are the ones that are the most helpless in the face of the harmful effects that global warming will and has incurred. History has told us that when the climate changes, species will either disappear from areas where they were once found or migrate to new areas that are suitable for their needs. A tiny butterfly called Edith s checkerspot was used in the first study of how a species reacts to warmer temperatures across its entire habitat. The populations of the butterfly were documented at one hundred and fifty-one cities of different latitudes across the world. The butterfly populations on the southern edge of its range decreased, with Mexican populations four times as likely to be extinct as those in Canada. It was also observed that southern groups of the butterfly had migrated to higher, and therefore, cooler elevations (Moore, 1997). It can be concluded from these results that a climate change procured from increasing temperatures will result in migrations and partial extinction of some species just as other climate changes have in the past. Some species, however, will not be as fortunate as the Edith s checkerspot butterfly. With the exception of five prehistoric eras of mass extinction, only 2 to 4.6 families of species per million years have become obsolete. However, it is predicted that in the next century alone, we will see the extinction of fifty families of plants which will result in extensive expirations of many of the associated animal families and insects (Mitchell, 1997). The website of the Wildlife Federation of America claims that the a species of tree frog has become extinct and relates this directly to global warning cite this with the website.
The human populace, the primary instigators of the global warming effects, will also suffer increases in vector-borne diseases such as malaria and yellow fever as a consequence of a warmer environment (Watson, 1997). In Rwanda, for example, the number of malaria cases has doubled since the 1960 s. This increase is correlated with a temperature rise of nearly 1.73616 degrees Celsius in that area. The disease even spread into areas where it had been almost completely absent. The unusual spread of malaria was probably related to the fact that mosquitoes, the primary carriers of the disease, thrive in warmer weather (Moore, 1997). It can be presumed that a warmer climate will mean the spread of diseases to areas of the world where the inhabitants have no previous immunity. A future filled with new waves of epidemics could be in store for the human race.
The concept of global warming predicts an ominous future for the inhabitants of planet Earth. Every aspect of life will be affected, from the smallest insects to the human population. Temperature augmentations will affect agriculture, the world s oceans and topography, and biological ecosystems. Evidence of this is already apparent in such examples as the Edith s checkerspot butterfly, glacial melt, and the coral reefs. Many scientists feel, however, that a combined effort of the whole human race may be able to reverse the current effects of global warming and prevent even worse future ones. A switch to energy resources that do not emit greenhouse gases would be one possible option. Robert T. Watson suggests a conversion to renewable energy sources such as wind, solar power, and biofuels. Improving the management of forests and agricultural lands would combat the effects of global warming, in addition to improving the air quality of the planet. It is believed that a better understanding of the earth s complex environmental system will be helpful in the attempt to combat global warming.
Environmentalists and scientists emphasize the fact that humans are primarily responsible for global warming and therefore it is up to us to slow or reverse the process. Now things lie up to President Bush many say. The key question is whether he will choose some new way to get governments to agree to binding cuts in greenhouse gases or revert to the approach sought by his father, who at the 1992 Earth Summit in Rio signed the Framework Convention on Climate Change, the treaty that called only for voluntary reductions in the gases.(Revkin, 2001) Now the only question left is that with global warming becoming more of a problem every year will society do anything to prevent the inevitable or will we continue to ignore the fact that global warming is negatively affecting the Earth and its inhabitants.