There is no doubt that the atmospheric buildup of greenhouse gases is largely the result of human activities. By increasing the levels of greenhouse gases in the atmosphere, human activities are strengthening Earth's natural greenhouse effect. Figuring out to what extent the human-induced accumulation of greenhouse gases since pre-industrial times is responsible for the global warming trend is not easy though. This is because other factors, both natu

Improving our understanding of the potential risks, the magnitude, and extent of any man-made global warming will require a significant amount of critical scientific investigation. The climate has been changing for thousands of years on a natural cycle of highs and lows that humans have adapted too. If the temperatures are warming, the events arising from the change will not affect the way humans have been living for thousands of years. Natural variations can be causing the slight increase in global temperatures that are being observed and in that case, people have only Mother Nature to blame. Scientists and politicians who are looking for funding can also be blamed for the distribution of selective facts that are not revealing the whole truth to the public. With the real facts, global warming will have a minor effect on the global community if any at all. Until the uncertainties are discovered and understood to a degree that is necessary to accurately predict the warming trend in the future no economically destructive or expensive standards should be implemented.

One of these variables causing a variety of troubles in predicting global warming is the cooling effect of particles in the upper atmosphere. Most of these particles, that include sulfates, are emitted into the atmosphere via volcanoes. Volcanic activity affects the way the earth atmosphere heats and cools in a tremendous way. Dust from them has a "reverse greenhouse" effect. Small particles of ash rise high up into the atmosphere and lower the overall temperature of the world (Bryson 147). The recent eruption of Mt. Pinatabo in 1992 in the Philippines blew a colossal amount of sulfates (an atmospheric cooling agent) into the stratosphere, causing a worldwide drop in temperature on average of half a degree that lasted two years (Suplee 47). Then there is the volcanic eruption of Toba 73,000 years ago. Toba an Indonesian volcano erupted with enough force to send more than 600 cubic miles of volcanic material into the atmosphere. The eruption was the largest of the past 500,000 years (Warnings 1). Such violent caldera eruptions can drastically alter global climate, by spewing so much ash and sulfur compounds into the air as to block sunlight and lower temperature worldwide by many degrees C (Graedel 20). Thus, an almost total absence of major volcanic blasts between 1920 and 1940 may have been responsible for the period of unusually rapid warming that was recorded, rather then the increase in atmospheric green house gases, which levels were rising at the same time (Silverberg 54). Other natural effects that are uncertain in their effect on variations in the warming and cooling of the earth are the seas and the rain forests. CO2 can remain in the atmosphere for as long as a century, a situation aggravated by the cutting of the Brazilian rain forest, the world's largest land-based absorber of CO2 (Suplee 63). At this time one-third of Brazil's trees have been cut down to provide grazing land for cattle, which produce methane another global warming agent (Brown 77). However, as the trees on Earth are absorbing 0.5 billion tons CO2 a day, the world's oceans are absorbing 4 billion tons (Suplee 47). The oceans serve as a vast "sink" for carbon dioxide by absorption by terrestrial and marine plants, the oceans sediments, and in seawater (Suplee 47). Furthermore, of the 7 billion tons of emissions sent into the air every day, only 2.5 billion tons remain in the air (Eisler 84). A question arises from this: How

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Approximate Word count = 2371
Approximate Pages = 9 (250 words per page double spaced)