Can you post some sources? My cursory research has shown the opposite.

http://en.wikipedia.org/wiki/Polar_bear#Population_and_distr...

http://www.arctic.noaa.gov/essay_schliebe.html

http://www.usgs.gov/newsroom/special/polar_bears/

http://www.polarbearsinternational.org/ask-the-experts/popul...

http://www.wired.com/wiredscience/2008/07/polar-bear-decl/