Canlorbe: You say polar bears are far less endangered by global warming than by environmentalists dreading ice melt. Could you expand?
Dr. Soon: Yes, indeed. I have argued that too much ice will be the ultimate enemy for polar bears. Polar bears need less sea ice to be well fed and to reproduce. Why? Think about this for a minute: Polar bears eat a lot. Any large colony will need a great deal of food. The bears' staple diet is seal blubber. But seals are a long way up the food chain. So a fully functional and healthy eco-system is required. And that means oceans warm enough to support the lower links in the food chain from plankton all the way up to seals.
Indeed, a good puzzle for polar-bear science is to answer the question how polar bears survived during the ice ages, when ice covered coastal zones and large parts of the global ocean. Ice was piled miles deep on land, making it extremely difficult for eco-systems to provide enough food. Of course, areas of relative warmth, which population biologists call refugia, always exist. They may well be the key to explaining how polar bears survived the Last Glacial Maximum about 21,000 years ago.