Polar bears face up to warmer future

For the past 30 years or so, people living in Canada's north have been noticing a phenomenon that many scientists now believe is a direct result of our planet warming up.

The waters of Hudson Bay - and many other northern seas - are beginning their annual freeze later each year.

This November, local residents are saying that the waters are up to a month late in freezing up. Similarly, in spring the ice is breaking up earlier.

The net result - polar bears have less time on the solid ice to hunt