Argument45 [OB小组]_第13次作业_北极鹿之减少

ldongxpUID: 2311083

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: 609         TIME: 00:30:00 +25         DATE: 2007-7-25 22:01:54

In this argument, the author concludes that the decrease of arctic deer populations is due to deer being unable to follow their age-old migration patterns across the frozen sea because global warming trend caused that the sea ice melt. To support this conclusion, the author cites a report of the local hunters, in which the deer populations are decreasing. The author also notes that there is a coincidence between the recent global warming and the decreasing of the deer population. However, this argument suffers from several critical flaws and is therefore unconvincing as it stands.

First of all, whether the populations of arctic deer are indeed declining is questionable. The author fails to provide evidence that the reports from local hunters are able to reflect the real situation of the arctic deer populations. Perhaps many arctic deer move from the island the hunters did not check the number of arctic deer to the islands the hunter had checked. Thus the hunters made a mistake in counting the number of arctic deer and they thought the population of the arctic deer declined. Or perhaps the hunters did not go to all the islands to check the numbers of arctic deer so that they overlook some arctic deer. Unless the author substantiates that the reports reflect the true population of arctic deer, he cannot make me convinced based on such reports.

Another problem with this argument involves the assumption that the decline in arctic deer populations is caused by being unable to follow their age-old migration patterns across the frozen sea. The author overlooks other factors that can also lead to this result. For instance, the plants on which the arctic deer feed might die out because sudden cold weather and thus many arctic deer starve to death. Or perhaps, the hunters hunted more arctic deer for their fur and therefore fewer deer left. It is also possible that there is an epidemic disease among the deer causing death and therefore the number of arctic deer declined. Without ruling out these and other explanations for the declining of the arctic deer populations, the author cannot make a sound conclusion based on such an assumption.

Even assuming that the decreasing in arctic deer populations is due to being unable to follow their age-old migration patterns across the frozen sea, the author unfairly  assumes that the global warming caused the ice melting in the areas where arctic deer live, letting alone stopping them from migration. The global warming does not necessarily indicate that the temperatures in the habitat of arctic deer increased. Maybe the habitat of arctic deer  become slightly colder though the temperatures in most places in the world increased; thus the ice for arctic deer to move over might not melt and the deer can follow their migration as before. Even the temperature in the habitat of arctic deer increased, the temperature may increase just a little and this do not accelerate the melt of the ice. For that matter, the global warming may not affect the life of arctic deer at all. Without accounting for these and other possibilities, the author cannot assume the global warming cause the declining of population of arctic deer, letting alone making a persuasive conclusion.

In sum, this argument is unpersuasive as it stands. To bolster this conclusion, the author must provide clear evidence that the populations of arctic deer are indeed declining and that the decreasing is caused by the global warming. To better assess this conclusion, more information about the situation of the places where the arctic deer live and more detail about the declining of the arctic deer population are needed.