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

This argument concludes that the decline in deer populations is the result of global warming. It is based on premises that arctic deer live on islands in Canada's arctic regions, that they search for food by moving over ice from island to island during the course of the year, that their habitat is limited to areas warm enough to sustain the plants on which they feed and cold enough to allow the deer to travel over for the ice to cover the sea separating the islands, that local hunters report that the deer populations are declining, that these reports concide with recent global warming trends that have caused the sea ice to melt, and that the deer's being unable to follow their age-old migration patterns across the frozen sea as a result of former premise. However, this argument is logically flawed. There are many evidences are needed.

First, the effect of global warming is large enough to make deer unable to follow their age-old tradition. Despite the argument treat this as definitely true, it is worth to doubt. What if the global warming just made small part of the sea ice melt? In addition, the effective areas could be environments where deer don't like to live. As a result, that should have never caused the decrease of deer. What's more, the global warming could increase the number of deer regarding that the areas which are warm enough are more.

Second, deer have to follow their old rule, i.e. searching for food by moving over ice from island to island. Although animals might have tendency to follow their old habits, there are still examples that plenty of animals change their patterns to adapt to the change of circumstances. For instance, deer can find some place warm enough to grow the plants which they need and their food and provisions are enough to subsist on. That is, they don't need to migrate anymore.

In the end, the argument that focusing on the decline in deer populations is the result of global warming is rather weak. If the author give the evidences that the effect of global warming is large enough to make deer unable to follow their age-old tradition, and that deer have to follow their old rule to search for food from island to island, this argument will be greatly enhanced. In spite of this, there is no reason to accept the conclusion, because there are many evidences needed to be included.