Boston Globe: I had always considered global warming an alarming, but strangely abstract concept, until the phenomenon took on a human dimension here in the Canadian High Arctic. Known as one of the great breeding grounds of northern seabirds, much of this eastern island is covered with a tongue of ice that remains from the Wisconsin glaciation, which gave up its grip on most of North America some 15,000 years ago. But here the glacier lives on, indistinguishable from the permanent polar ice. Six …