Why is the monarch butterfly considered endangered?

The Monarch Butterfly population, as well as numerous other animal species, is suffering the effects of man-made events as well as the consequences of the "global warming" phenomenon.

Scientists assert that the global climate change may cause the Monarch's over-wintering sites in Mexico to become wetter, and the spring and summer breeding areas of the United States west coast and mid-western agricultural belt to become warmer. As temperatures become too warm for this species, their summer migrations may take them even further northward.