Arctic deer live on islands in Canada's arctic regions. They search for food by moving over ice from island to island during the course of the year. Their habitat is limited to areas warm enough to sustain the plants on which they feed and cold enough, at

The argument implies that due to global warming the deer are unable to follow their age-old migration patterns across the frozen sea because of which the population is diminishing. It is very much true that global warming has caused large number of glaciers to melt and an increase in temperature might have led to the defrosting of ice in Arctic regions in Canada. Due to which the deer cannot migrate across islands in search for food. And this, the author concludes, is the reason for reduction in the arctic deer population. This is a valid reason, but it is one among many and the author has not explicitly studied other causes for the declination.

Global warming in itself is the cause of many problems other than defrosting of ice. The author said that these arctic deer fed on plants which are sustained in a particular type of climate. Due to global warming, the balance which those plants need might have got disturbed and which would have lead to scarcity of food for the animals.

Also, global warming may lead to unbalance in environment in which an arctic deer needs to live and grow. We know that all the living organisms mutate for survival. The change in their biosphere might have caused mutation in the new ones which would not have been stable. Or due to this change in their biosphere, there might have been an epidemic causing the deaths of many.

The author also claims that the decline in population was reported by local hunters. The hunters obviously hunt deer and hence these hunting can also be a cause of their decadence. What if the number of deer being hunted have increased, or if there is an increase in the number of hunters – these are also plausible reasons for the reduction in population. So the mention of recent activities of hunters could have helped author to frame the argument more persuasively.

By summing it all up, I would like to conclude that the argument was not substantially reasoned and the study of a few more plausible causes might have made the argument persuasive.