Global Warming Too Hot or Not? the Theory of Global Warming Proposes That Man's Activities Are Causing the Earth to Heat Up, but There Is Compelling Scientific Evidence That Does Not Support This Conclusion

Article excerpt

Very few people have heard of the Larsen B ice shelf. For thousands of years in the Antarctic, the place was a desolate frozen wasteland, crisscrossed by crevasses and swept by powerful ice and snowstorms. Beginning in 2002, satellite imagery began to show instability in the Larsen B ice shelf. According to research published by the journal Nature, much of the more than 4,600 square mile ice shelf collapsed. Since then, icebergs have continued to be formed from the formerly stable ice shelf and from glaciers that are now flowing more quickly from the ice-bound continent. The cause of the Larsen B breakup, according to many, is global warming.

Moreover, Larsen B is not the only strange and extreme geological or weather event to be blamed on global warming. In Europe, the famous Matterhorn, reportedly, is falling apart as the glaciers that once held it together retreat. "All the rock fractures generally held together by the ice, which acts as a glue, give way because the ice melts, leading to a situation of instability," global-warming scientist Michelle Comi told ANSA, the Italian news agency. "Geologically speaking, the process is normal. What isn't normal is the acceleration of these phenomena."

Other scientists, working in other regions, claim to be witnessing similar changes. A team of scientists from the University of Texas at Austin noted in August, for instance, that the Greenland ice sheet is melting faster than anticipated. Led by Jianli Chert, the UT team asserted that Greenland is now losing 57 cubic miles of ice each year. "This is a good indication of global warming, that it's there," Jianli Chen told the Houston Chronicle. "At least, it's happening in the Arctic."

According to most media reports, a substantial consensus exists among scientists that global warming is real, that it is of human origin, and that it poses an unprecedented threat. Though this is how the media reports it, there is, in fact, a great deal of debate about the situation. Many climate scientists disagree with the anthropogenic--that is, human-caused--global-warming hypothesis. The UN's Intergovernmental Panel on Climate Change (IPCC), however, represents the alleged consensus. The IPPC argues: "Greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise." According to Science, the journal of the American Association of the Advancement of Science, other major scientific bodies agree with the IPCC assessment. "The American Meteorological Society, the American Geophysical Union, and the American Association for the Advancement of Science (AAAS) all have issued statements in recent years concluding that the evidence for human modification of climate is compelling," wrote Naomi Oreskes of the University of California at San Diego.

Such apparent agreement among scientists suggests that the science behind global warming is robust and persuasive. However, though the evidence, they say, seems to indicate that the Earth is warming, how much, how quickly, and what exactly is responsible remain matters of debate.

The Human Factor

The leading theory on global warming--the one that gets all the press, is debated in Congress, and shows up on popular science programs on cable TV--holds that the planet is getting warmer because human industrial activity over the last century is filling the atmosphere with carbon dioxide (C[O.sub.2]), a greenhouse gas. According to this theory, carbon dioxide in the atmosphere prevents heat from escaping into space. The retained heat causes an increase in temperatures.

The retention of heat in the atmosphere is in fact a natural phenomenon known as the greenhouse effect. Without it, the planet would be far too cold to permit life as we know it. The standard model of global warming holds that this essential natural process is being supercharged by greenhouse gases released by human activities, allegedly causing the Earth to retain more heat than it would normally. …