The unexpected repercussions of global warming

Interesting story from Canada. Apparently they found a bear that is an offspring of a grizzly and a polar bear, which in the wild is extremely rare because of different mating rituals and roaming territories.

But apparently global warming is responsible for this too, since the grizzly bear population seems to be pushing its territory's boundaries northward now that the weather is warming up.

Obviously, this is a worrisome development because the interbreeding will diminish the gene pool of the polar bear, threatening it's survival and ultimately existence:

"As grizzly bears expand their range north, (inter-breeding) becomes another potential threat to polar bears," said [geneticist] Mr. Paetkau. "If there’s too much inter-breeding, the grizzly bear genes could eventually wash out the polar bear, and they could become basically grizzly bears with a little more northern habitat."