Habitats of polar bears are expected to shrink dramatically over the coming decades, the International Union for Conservation of Nature warned Thursday, urging immediate action to save the Arctic animals. \"A study by IUCN predicts a dramatic reduction in polar bear habitats over the next 10 to 50 years, due largely to global warming,\" said the conservation group in a statement. The IUCN noted that annual sea ice is expected to shrink between 10 and 50 percent by 2100, due to climate change. A recent study has also projected that summer sea ice would be gone in as early as a decade\'s time, said the environmental group. \"Now is the time to act in order to save the waning polar bear population,\" said Dag Vongraven, who chairs the IUCN\'s polar bear group. \"If we fail to make a stand to save this species, we risk having the population become severely decimated, and quite certainly they will have disappeared from many areas where they\'re found today,\" he added.