To understand the reason for the researchers’ cautious optimism, we must first understand the factors that are threatening the polar bear’s existence. Polar bears consume a diet of mainly young seals. In order to hunt these seals, polar bears need to rest at the top of sea ice---the same ice that is increasingly melting for most of the year thanks to climate change. In another 50 years, experts expect that the Arctic will be too warm for sea ice to form for half of the year, leaving polar bears without a reliable food source and in serious danger of starvation.