In an unusual decision, the Interior Department declared the polar bear species to be officially "threatened," under the Endangered Species Act, because of global warming.

Scientific evidence shows that the shrinking Arctic ice cap will no longer support the polar bears' habitat by the middle of this century. The implications of this ruling are not entirely clear. In this video, a Bush administration official and an environmentalist discuss the announcement's impact on the climate change debate.

"The listing today acknowledges the fact that we've lost habitat, which is sea ice, which is essential for polar bear survival." - Lyle Laverty, Department of the Interior

"The U.S. government based its decision to protect the polar bear on computer modeling that were based on the reality of global warming." - Andrew Wetzler, Natural Resources Defense Council

1. What is global warming?

2. What is an endangered species?

1. Why did the government label the polar bear threatened?

2. Do you think the government will do more to address global warming because of the polar bears? Should it?

3. What is the value in protecting animals from extinction?