I'll probably be attacked for posting this. But integrity and accuracy SHOULD be important in trying to address this complex issue. We agree on something, I see.
And yes, the melting of the polar ice cap is not unequivocally due to anthropogenic climate change. Gore didn't say that either, but the writer of this piece mistakenly did.
In your opinion, which is it? Is the word "not" meant to be in your statement? For the record, I don't believe that any melting of the polar ice cap is due to anthropogenic climate change [note how the hot words used by the believers are now "climate change" not "global warming"].
Here is something for the reader to look at and draw your own conclusion:
Arctic sea ice, May 11, 2008 compared to May 11, 1983
The melting of the polar ice cap is consistent with expectations of effects due to anthropogenic global warming, but it is not
unequivocally caused by it. There's a phrase out there called "polar ampliflication" which basically means the as the global warms, the high Arctic will warm disproportionately, i.e., more than the globe take as a whole. Accelerated Arctic sea ice melt would be one consequence of polar amplification. I know that IPCC projections indicate accelerated loss of Arctic sea ice, slower than what has actually been observed over the past decade.
Also note that reduced sea ice cover feeds back negatively, because open ocean waters absorb sunlight and will subsquently warm due to that effect.