Polar Bears: On Thin Ice
It prowls the globe's frozen north, a massive white bruin that fears no predator. The polar bear is both a totemic symbol of Canada and an important part of the Arctic ecosystem. But as four decades of intensive study has shown, climate change is threatening polar bear populations. CBC Digital Archives presents a dozen clips about how these bears of the great white north have gone from trophy hunter's quarry to nuisance to protected species.