Wow! You've really outdone yourself this time, Adrena! The polar bear defense is infallible! How did I not see it before?!

You're looking at the subject with blinders. Polar bear population has increased due to hunting of polar bears being restricted. The loss of the tundra would be a calamity for the polar bear. Again, such parochial views are irresponsibly dangerous.

See:

http://www.iucnredlist.org/search/details.php/22823/all
http://neptune.gsfc.nasa.gov/publica...%20Warming.pdf
http://umanitoba.ca/ceos/files/publications_pdf/058.pdf
http://goliath.ecnext.com/coms2/gi_0...f-sea-ice.html
http://icb.oxfordjournals.org/cgi/content/full/44/2/163
http://amap.no/workdocs/index.cfm?di...CIA%2Foverview
http://www.bioone.org/perlserv/?requ...F2006-180&ct=1
http://pubs.aina.ucalgary.ca/arctic/Arctic52-3-294.pdf
http://dx.doi.org/10.2193%2F2006-180
http://www.usgs.gov/newsroom/special...ast_lowres.pdf
http://www.biology.ualberta.ca/facul...imate_2007.pdf