【Flyer杀G作文组】第十八次作业7月26日Argument45-By 但我

但我UID: 2763822

45. 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."
The assertion is that the cause of the decline in artic(arctic) deer population is deer being unable to follow their age-old migration patterns across the frozen sea, for the sea ice is melting due to the global warming trends. To support his argument, he takes the local hunters' report as an example, which said the deer populations were declining with the global warming trends. At first glance, the author's assertion might sound reasonable, however, the consequent conclusion are undermined by several logic flaws.
One of the premises of this assertion is the temperature in local areas is really increasing. But the arguer didn't offer any data to prove that. He or she only has the evidence that the globe has warming trends. But the global warming trends cannot be representive of the local climate, it is only the average level of the worldwide climate, perhaps the temperature in some areas of the world is increasing sharply to upraise the average level while in Canada's artic region the temperature trend is the opposite direction or remain static.

The arguer infers the number of deer(deer单复数同形) is declining only on the basis of local hunters' reports. It is not adequate to prove that the actual number of deer is really in decline. It is quite possible that hunters deem that the deer populations are declining only because they couldn't hunt as many deer as before. But whether the time, areas or habits of these hunters are in accordance with those of arctic deer is still in doubt. All of these factors will influence the number of deer they saw.
Another premise that the increase in temperature will lead to a decrease in the number of deer may not be established either. For the arguer didn't provide any evidence to verify if the temperature is ascending, and the environment is changed, then the deer would die. The temperature rises may lead to a change in the deer's habit, and their activity patterns may need to make some change, but all these may not bring about the death of deer.

Moreover, the consectary of the argument is too arbitrary. He thought the increase of deer populations lead to the change in the form of migration mode other than other factors. Whereas the over-hunting of hunters, a sharp decline in the food of deer will also lead to the same outcome.

In total, to strengthen the persuasion of this argument, the author still needs to provide the current population of deer and exact evidence to validate the local warming trends. Moreover, whether the habit of deer is being threatened requires to be further investigation.