TOPIC: ARGUMENT45 - The following appeared as an editorial in a wildlife journal.
"Arctic deer live on islands in Canada's arctic region. They search for food by moving over ice from island to island during the course of a year. Their habitat is limited to areas warm enough to sustain the plants on which they feed, and cold enough, at least some of the year, for the ice to cover the sea separating the islands, allowing the deer to travel over it. Unfortunately, according to reports from local hunters, the deer populations are declining. Since these reports coincide with recent global warming trends that have caused the sea ice to melt, we can conclude that the decline in arctic deer populations is the result of deer being unable to follow their age-old migration patterns across the frozen sea."
WORDS: 524 TIME: 00:53:03 DATE: 2008-10-4 10:52:25
The author of this argument claims that the global warming led to the falling of the Arctic deer populations. To justify his or her claim, the arguer cites a survey result from local hunter which indicates the decline of deer number. Moreover, the author also points out that global warming in the same period time was responsible to the melting of sea ice. This excerpt seems to be convincing and plausible; however, after close scrutiny, I find it contains logical flaws in several critical respects, as the following discussion shows.
The first problem with this argument is that the author's conclusion is based on the research of a group of local hunters, which is not statistically reliable. When statistic results are used to make general claims about a particular phenomenon, an author is responsible to assure its randomness and representativeness. In this argument, the author failed to take this rule into consideration, which makes the conclusion unfounded. It is entirely possible that those hunter's active regions are quite limited and deer happened not to appear in these sites. Without ruling out this or other similar situations, the speaker cannot confidently draw the conclusion that the populations of deer have dropped.
Secondly, by citing the global trend of warming to support his or her conclusion, the speaker relies on the unwarranted assumption that the worldwide situation applies specifically to Canada's arctic region. Without any supporting evidence that the climate in North Canada are also getting warmer, it is hasty to conclude that the frozen sea in arctic region is melting and the habit of Arctic deer has been changed. Perhaps the effort of Canada government to prevent climate change in this nation has positive effects on average temperature in Canada's arctic region, while the temperature in other countries has risen sharply in recent decades.
Finally, even if the population of Arctic deer is descending as the hunters described and if the average temperature in North Canada is rising year by year, the author's conclusion is still open to doubt. The argument relies on the groundless assumption that Arctic's disappearing was attributable to the global warming. Yet, the only foundation for this causal relation is that there was a correlation between these two phenomena, and the arguer failed to account for other instead factors which were reasons for Arctic deer's falling. Perhaps large scale of hunting has killed those deer; or perhaps an unknown disease was spread among deer groups. Since the argument failed to eliminate these alternative explanations, the author's assertion is indefensible.
To sum up, the author's conclusion about Arctic deer's population and global warming is not well supported. To bolster his or her argument, the speaker must prove that the survey on deer's number is believable and their population did suffer from a decline. Similarly, to better support the conclusion, the author is expected to provide more information which can show that the climate of arctic region in Canada is also influenced by the global warming. Furthermore, to make it logically acceptable, the arguer should also demonstrate that a warmer climate is the most important reason for the falling of Arctic deer populations.