What Is Global Warming?

There is one of the most sensitive global climate issues for years, which is global warming. In general, we know that the origin of global warming is the emission of carbon dioxide. It was verified that the relationship between carbon dioxide and temperature: when there is more carbon dioxide the temperature gets warmer. This topic should be discussed under current situation to advocate people concerning with this severe environmental issue. Meanwhile, people should consider how to reduce the emission of carbon dioxide and take some actions to stop global warming. What is global warming? What caused global warming? What are the negative effects caused by global warming? What can we do to save the earth? Are there any positive effects? In the next paragraphs, I will explain these questions in details.

What is global warming? Global warming is the increase in the average temperature of Earth's near-surface air and oceans since the mid-20th century and its projected continuation (Brown 22). According to the 2007 Fourth Assessment Report by the Intergovernmental Panel on Climate Change, global surface temperature increased 0.74 ± 0.18 oC (1.33 ± 0.32 oF) during the 20th century (Keppler). In nearly 100 years, the average global temperature goes through four fluctuations: cold, warm, cold again, and warm again. After 1980s, the temperature was ascending obviously.

What caused global warming? It is caused by several factors. First, population explosion is one of the main factors of global warming; it also threatens the balance between man and nature. Second, atmospheric pollution is being on the rise, and it has already become an international major problem. It is also the basic problem of global warming. Third, marine ecology and environment took a turn for the worse. That may lead to the damage of fresh water resouces. Forth, erosion, salinization, and desertification of land make the ecological environment deteriorated, and flood and sand storm may happen more frequently. Fifth, the forest resources are sharply decreased by natural changes and human actions. Sixth, acid rain can destroy the forests, acidate lakes, and endanger animals. Seventh, water pollution destroyed the balance between the demand and supply of fresh water. Last, toxic chemical wastes have threats on the ecological environment on the earth' surface. (Brown 46).

What are the negative effects caused by global warming? This serious environmental problem generates amount of destructive effects to the entire planet: ice melting, climate change, animals and plants' extinction, and threat of human society. Primarily, as the temperature increases, ice melting is regard as the most intractable issue. Melting of ice raises the sea level. Jonathan Overpeck, an earth scientist at the University of Arizona in Tucson thinks sea level rise will occur at rates of up to a meter or three feet per one hundred year (Brown 102). This statistic reveals the raising temperature is detrimental to global climate and the main reason why global warming results in sea level rising are strongly due to thermal expansion (Brown 102). When the temperature of the sea becomes warming than before, the sea level will rise. In addition, as a result of ice melting, landscape also transforms. Meanwhile, global warming also causes climate change to bring about many other awful effects such as more destructive storms, more fire disaster and more intense droughts.

The second effect of global warming is to make many animals and plants endangered. Considerable data verified that more than 200 native plant species in the United States have gone extinct; more than 760 plant species in the U.S. are federally listed as endangered or threatened and 20 percent of our native plant species are in decline and on a conservation watch list (Keppler). As same as plants, there are also many endangered animals generating which are imputable to global warming, such as Polar bears. Some scientists believe the Polar bears in Alaska would become extinct in 50 years' time (Keppler). These data warn us that we call for paying effort on survival of species.

The last negative effect of global warming is more related to humankind. Global warming will also threaten human society. It will cause the infectious diseases too easy to spread and infect. Bacteria will hard to control through fast breeder reactor, and threat our lives. The house will be eroded by destructive insects and it may lead a vagrant life eventually. What's more, global warming impedes outdoor activities. Some outside entertainment sports such as skiing and snowboard will be influenced by ice melting and climate change.

Nevertheless, when we face these negative affects which caused by global warming, what we could do to against it? A survey conducted by Yale University and George Mason University found that the number of Americans who believed that climate