Yes they are a threatened species. But not by number, but by their average weight. Due to short ice seasons, polar bears cannot hunt and build their fat for the winter season. Without this coat, females are unable to reproduce or survive the winter conditions. So the polar bears numbers will decrease as the temperature up north will increase. I praise the US for putting the polar bear on the list.
Alex_murderer, you are truly clueless aren't you. Stop jumping to conclusions based on your point of view. Evolution takes hundreds maybe thousands of years to occur. The reason why the polar bear cannot adapt is because these changes were harsh and very rapid. The perfect example of evolution is our society, from cavemen to the roman empire to the middle ages to the industrial period to today. These changes were progressive, it all happened in a period of over 3000 years. Animals dont just change from one day to another, for example: why dont you grow gills like a fish when you drown? It is survival, yes, but genetics doesn't work that way.